Processing Chrome Tannery Effluent to Meet Best Available … · 2018-06-13 · EPA-600/2-79-110 July 1979 PROCESSING CHROME TANNERY EFFLUENT TO MEET BEST AVAILABLE TREATMENT STANDARDS

Processing Chrome Tannery Effluent to Meet Best Available Treatment Standards

EPA-600/2-79-110 July 1979

PROCESSING CHROME TANNERY EFFLUENT TO MEET BEST AVAILABLE TREATMENT STANDARDS

Lawrence K. Barber A. C. Lawrence Leather Co., Inc. Winchester, New Hampshire 03470

Ernest R. Ramirez Swift Environmental Systems Chicago, Illinois 60680

William L. Zemaitis Envirobic Systems

New York, New York 10001

Grant No. S 804504

Pro j ec t Officer

Jack L. Witherow Food and Wood Products Branch

Industrial Environmenta1 Research Laboratory Corvallis, Oregon 97330

INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY OFFICE OF RESEARCH AND DEVELOPMENT

U.S. ENVIRONMENTAL PROTECTION AGENCY CINCINNATI, OHIO 45268

FOREWORD

When energy and material resources are extracted, processed, converted, and used, the related pollutional impacts on our environment and even on our health often require that new and increasingly more efficient pollution control methods be used. The Industrial Environmental Research Laboratory- Cincinnati (IERL-Ci) assists in developing and demonstrating new and improved methodologies that will meet these needs both efficiently and economically.

The A. C. Lawrence Co. has demonstrated a highly efficient wastewater treatment system at their chrome tannery in Winchester, N. H. The system uses flow equalization, primary treatment by chemical addition and air floation, and secondary treatment in an oxidation ditch. Removal of both carbonaceous and nitrogenous materials was accomplished. This study will be of great interest to the entire leather tanning industry. The Food and Wood Products Branch, IERL-Ci, may be contacted for further information on the subject .

David G. Stephan Director

Industrial Environmental Research Laboratory Cincinnati

iii

resale or denatured (pulped) hair, most of which enters the waste stream in the form of fine particles. Section 2 describes the shearling process, and Section 9 presents designs for complete cattlehide processing systems.

The wastewater treatment system selected for the Winchester tannery was chosen from a number of options. sometimes called LectroClear, was favored for several reasons:

The electrochemical primary system,

1.

2.

3.

4.

5.

The presence of large quantities spent fatliquor solutions and emulsified lanolin, wool grease, and animal fat all well dispersed, dictated a clarification system that would involve flotation rather than gravity separation. Laboratory-scale demonstrations clearly indicated that the floated skimmings would have a much higher solids content (perhaps on the order of 10x) than a gravity system could deliver. handling, and dewatering would thus be expedited. The continued flotation effect provided by the electrodes in the flotation basin seemed to maximize primary clarification. The electrolytic generation of chlorine coincident with the other products of electrolysis appeared to have the beneficial side effect of providing some disinfection. At the time of selection, ammonia reduction was thought to be occur- ring within the LectroClear system. but it was later found to be untrue.

Sludge storage,

This effect was a possible plus,

The secondary system was likewise selected from a number of possible choices. The carrousel concept, which is a technical modification of the Passveer oxidation ditch, was brought to our attention by EPA and leather industry representatives who visited Holland in 1974. They reported rather en- thusiastically the simplicity of design, low cost, minimum land requirement, adaptability to northern winter climate operation, ease of control of dissolved oxygen, and low operating cost. In addition, the most important, this system was claimed to have the capability of both nitrifying and denitrify-

Because all of these factors seemed to indicate superiority over other known systems, consultant help was secured, and the decision made to install a carrousel unit.

- ing.

The choice of a sludge dewatering device was affected by the fact that the land area of the tannery property was limited, and solid waste from the treatment plant thus had to be deposited at the regional solid waste manage- ment facility. Samples were submitted. The material was accepted with the stipulation that the dry solids content would consistently have to reach 35% to 4% (and preferably 4%). Only one device, a filter press, could relia- bly be expected to provide this performance.

The choices made in assembling this treatment plant have proved to be wise. Consistently high-degree removals of pollutants have been achieved, in most cases well in excess of discharge permit requirements.

2

SECTION 2

WET PROCESS DESCRIPTION

Shearling processing is a complex procedure using a much greater water- to-hide ratio than most tanneries. Because the wool is retained and it is desirable to keep the wool fibers attached to the pelts free from interweav- ing and tangling, the practice of swimming the skins in chemical solutions has been adopted. Other categories of tanning operations limit the chemical floats to the smallest possible amounts, The liquor-to-skin ratio, by weight, for each fill and drain is on the order of 2.5 to 1. With side leather, the ratio is apt to be 1 to 1, and in some individual instances, it may be as little as 0.25 to 1. water per pelt (7,500 gal per 1,000 lb of green salted weight as received), or on a weight basis, a ratio of 60 to 1. This seems very high, but is ne- cessitated primarily by the extremely soiled condition of the pelts as received. The tannery processes some 3,000 skins per day and discharges just under 300,000 gal of wastewater per day.

The Winchester tannery uses approximately 90 gal of

The process used at Winchester has evolved over many years of trial and error and has gradually been optimized by experience. There is no close- knit shearling trade group in the U.S. exchanging ideas for mutual benefit, nor is there any standard procedure for converting raw pelts into finished products. Many tannages are used in this tannery, ranging from glutaraldehyde to modified mineral and vegetable tannages, depending on the end use and characteristics desired in the finished shearling. The shearling process consists of soaking and washing, pickling, tanning, retanning, dyeing, and fatliquoring, drying, and dry finishing. This section describes the wet processing steps, or those contributing to liquid waste volumes.

Chemicals used in the soaking and washing process are soda ash, de- Skins are immersed in water in tergents (biodegradable), and bactericide.

batches of about 100 in a horizontal, semicylindrical wooden tub, on which a paddle wheel is mounted. The above chemicals are added, and the paddle wheel is rotated to provide a swirling action that enhances liquid contact with both the skin and the wool. the wash and rinse cycles. This is a overnight operation.

A number of fills and draws are executed during

3

PICKLING

Chemicals used in the pickling process include sodium chloride and sulfuric acid. Skins are immersed again in paddle vats and gently agitated, this time in 5% salt brine containing sulfuric acid sufficient to adjust and maintain the pH to about 1.8. Equiblibrium at the pH specified is achieved.

This operation is also an overnight one.

TANNING

Chemicals used in the tanning process are sodium chloride, basic chromium sulfate, and sodium formate.

Skins are again immersed and gently agitated in paddle vats to which the chromium tanning solution has been added. This requires a 2-day expo- sure. In some cases, depending on the product desired, the chromium solutions are retained and reused. In others, certain dyes are added that prevent reuse.

Chemicals used in this process are sodium chloride, basic chromium sulfate, sodium formate, emulsified animal, vegetable, fish, and mineral oils, and various dyestuffs. Similar equipment to that described in the foregoing steps is employed. The only significant difference in the dyeing and fatliquoring sequence is that much higher temperatures can be tolerated by the now chrome-tanned skins, and such elevations can be used to advantage in the exhaustion of the dye baths and fixation of the dyestuffs. The time periods required are relatively short - on the order of 2 to 3 hr.

All of the above operations are carried on at the ground-floor level of the tannery, and the liquid contents of the paddle vats discharge by gravity to in-floor drains and sewers. This means that it is possible for a number of vats to be discharging dissimilar solutions to the wastewater collection system at the same time. Generally the soak waters are the first to be sewered in the workday, beginning at about 3 a.m. and lasting until 3 p.m. The pickle liquors are dropped from about 11 p.m. to 11 a.m. The tan liquors from 7 a.m. to 2 p.m., and the color-fatliquor solutions from 7 a.m. to 3 p.m, The equalizing tank at the front end of the wastewater treatment works blends dissimilar solutions and absorbs surges in hydraulic flows.

The blended waste stream is thus a complex mixture of organic and in- organic chemicals, mineral and vegetable tanning materials, animal, mineral, and vegetable oils, both raw and solubilized, and a spectrum of dyes. It is a murky brew at best, sometimes red, sometimes blue, usually dirty gray, but always a challenge to any sanitary engineer. A typical analysis of a compo- 'site sample from the equalizing holding tank is as follows:

4

5

Treatment plant components are described briefly as follows. Sche- matic views of the primary and secondary treatment systems, the constant head box, the primary clarifier, and the carrousel are presented as Figures 1,4, 9, and 11.

The screen house contains a screen pit with a horizontal cylindrical rotating monel screen. has 5/32 in. perforations on 1/2 in. centers . mounted bar rakes that continuously remove accumulated coarse suspended solids

The screen measures 3 ft. diameter by 5 ft. long and It is equipped with link chain

Manufacturer: Exeter Machine Co., Inc. Lomura , Wisconsin

Raw Wastewater Pumps - 3

These are submerged pumps located in a sump adjacent to and having a water level the same as the screen pit referred to above. These pumps ele- vate the wastewater to the equalizing tank as required, and axe actuated by float switches in the collection sump.

Manufacturer: Flyte Corp. Model No. - 6 - CP - 3126 Capacity - 600 gpm. Mhp - 9.4

Holding and Equalizing Tank

See Figure 2.

This is used to accumulate wastewater during working hours, absorb flow surges, and serve as a supply tank to allow constant flow through the treatment system .

Construction: Concrete, circular. Size - 40 ft. diam. x 18 ft. deep Capacity - 170,000 gals.

6

F i g u r e 7. Bubble Classifier

13

Figure 10, F i l t e r P re s s

18

Fi.gur.6 1.3. F i n a l Cl-sri f i e r

20

22

Evaluation of processes for primary wastewater treatment began at Win- chester in 1971. During that year, following laboratory bench-scale work, a pilot plant using electrolytic microbubbles and suspended solids flotation was designed and constructed to treat 15 gpm. equipment were encouraging 'out not successful because of incomplete flotation of solids.

The preliminary runs with this

Modifications were made, and during the summer of 1972, preliminary test runs were repeated, These pilot tests clearly showed that the electroflotation basin alone was inadequate to give reproducible and consistently acceptable treated wastewater. Finally in 1973, an electrocoagulation cell w a s developed, designed, and installed just ahead of and in series with the electroflotation basin (Figure 9 ) . This step was the key to success.

During the summer of 1974, round-the-clock runs were made operating the pilot unit at 12 gpm. These tests lasted for several weeks, and the results conclusively showed that the two-step electrocoagulation electroflotation technology could provide the results desired.

1,2,3,4,5,6 Theory of the Electrocoagulation Process

The key step in this primary treatment is the addition of microbubbles to the wastewater after metal coagulants have Seen added and before the addition of a polyelectrolyte. that have suspended material of high specific gravity (3 and higher). In the electrocoagulation cell, the surface charges on the pollutant particles are neutralized by the metal coagulant. aggregate size of pollutants. Under these circumstances, the high density of the pollutants invariably leads to a rapid settling action.

This step is especially important in wastewaters

This condition brings about a growth in

The notable contribution of this new two-step technology is the addition of a buoyancy factor (microbubbles) to the pollutant particles. of particles and microbubbles is enhanced either by vortex action or other turbulence, which increases the probability of collision between pollutant aggregates and microbubbles. Once the microbubble and pollutant particle have collided and united, the addition of the polyelectrolyte flocculates the solid-gas aggregate

Pairing

and forms a gross floc that is buoyant.

23

SECTION 6

EXPERIMENTAL PROCEDURES

SELECTION OF PARAMETERS

Soon after this demonstration project was approved and accepted by E.P.A. a meeting w a s held at Winchester at which a l l of the principals of the program were present, including the project officer, the project director, the consultants, and local operating personnel. Data collection and analysis were discussed in detail. The parameters considered essential are listed in Table 2 , along with where and how the samples for them should be taken. In addition to those listed a number of daily measurements and readings were specified which would be needed to properly assess the performance and allow operating costs to be calculated. These were:

Pelts processed Lime consumed Alum consumed Polymer consumed Electricity consumed Dissolved oxygen at aerators one and two Depths of the top of the sludge blanket in the final c l a r i f i e r Primary sludge volume Secondary sludge volume wasted Outside temperature

Values for all of the parameters and readings f o r the special periods of this project are given in Section 7, Tables 6, 7, 8, and 9. The absence of chemical oxygen demand (COD) as an analytical parameter and measure of performance w i l l be noted throughout this report. the waste stream, unchanged during the treatment process, interfered with the analytical procedure to such a degree as to render the determination useless.

The high concentration of chloride in

SAMPLING PERIODS

Activated sludge operations are temperature-dependent, and most full- scale wastewater treatment systems are expected to reduce BOD more efficiently in summer than in winter. The claimed superiority of the carrousel design in this respect prompted a large share of the interest in this project. A special condition for data collection and analysis was set forth in a grant amendment dated August 23 , 1976. This condition was:

The sampling and data collection procedure in part IV-e of the proposal shall:

31

---be performed on not less than 25 days of typical operation during the winter and on not less than 25 days of typical operation during the summer.

At the time of selection of parameters and data readings it was established that operating temperatures for mixed liquors would be limited to a minimum of 21OC for summer operating conditions, and a maximun of 160C for winter. On eight occasions during the winter this rule was violated slightly, particularly toward the end of the operating week, when the warm wastewater from the tannery was sufficient to offset atmospheric cooling. temperature recording in the carrousel at S3 during the winter period was 15.60C. atmospheric interference, since the average of the outside highs and lows was minus 8.8, and the lowest low minus 260C.

The average

This result demonstrates the innate resistance of the carrousel to

SAMPLING

The following procedures were used for procuring samples at sample

S1 - wastewater from the holding and equalizing tank. points S1 through S4. See Figure 1 .

This is also called raw wastewater in this report. Four 1 liter grab samples were taken from the tank at approximately 2-hr intervals. at the end of each day.

An Isco sampling instrument was used. Ice was employed in the instrument. The device was programmed to sample 10 ml every 15 min.

sel. refrigerated, and composited at the end of each day.

times a day at about equal intervals, refrigerated, and composited.

These were refrigerated, and composited

S2 - effluent from LectroClear primary treatment.

S3 - grab samples taken at the discharge overflow weir of the carrou- These were taken four times a day at about equal intervals,

S4 - grab samples taken after discharge from the final clarifier four

The analytical methods used were those specified in: Methods for Chemical Analysis of Water and Waste 1976 U.S. Environmental Protection Agency

Since two periods of intensive sampling were specified for this project, 25 days of summer conditions and 25 days of winter conditions, sampling and analysis were performed five days each week for five consecutive weeks beginning September 12, 1977, and for 25 working days of seven consecutive weeks beginning December 12, 1977, and extending into February, 1978.

33

Discussion of graphs of a n a l y t i c a l r e s u l t s .

The r e s u l t s as depicted i n the graphs ind ica te opera t ional features and dependent va r i ab les t h a t have occurred dur ing the th ree periods. ments upon each graph follow:

Com-

Figure 14,

Figure lj.

Figure 16.

Figure 17.

Figure B .

Figure19 .

Figure20.

Figure 21.

Figure 22 .

BOD VS. Week: consistency w a s not e s t ab l i shed u n t i l about the 20th week of opera- t i o n , The o v e r a l l r e s u l t s ind ica te a BOD of 10 t o 20 lb/day (4 t o 8 mg/l) is r e a d i l y achieved. The special t es t periods do not ind ica te any abnormali t ies .

This graph i n d i c a t e s t h a t b i o l o g i c a l s t a b i l i t y o r

pH and Temperature VS. Week: t h a t t h e plant w a s pu t i n t o operat ion dur ing a very cold period

A notable ind ica t ion i n t h i s graph is

which w a s genera l ly much co lde r than the winter of 1977-78. curve might seemingly indicate t h a t the reason f o r the long break- i n period w a s t he cold weather, b u t o the r f a c t o r s such as opera- t i o n a l problems i n the primary and secondary and o v e r a l l p l a n t break- in problems were equally s i g n i f i c a n t .

F/M VS. Week: w a s not reached u n t i l about t h e 20th week of operat ion. BOD e f f i c i e n c y is seen t o occur dur ing the lowest F/M loading periods.

This

This curve shows that the design F/M of 0.06 The b e s t

Sludge Age VS. Week: This curve ind ica tes t h a t the sludge age is over 30 days which insures the sludge t o be ae rob ica l ly d iges ted .

MISS, MLVSS, and SVI vs . Week: This curve ind ica tes a very good set of values f o r SVI, bu t it a l s o shows t h a t t h e MISS is much higher than designed o r expected.

Suspended S o l i d s VS. Week: This graph ind ica tes a higher than expected amount of suspendedsdlids i n the e f f l u e n t . The very high MISS o r s o l i d s i n t h e ae ra t ion u n i t can be imagined t o be the cause, bu t o the r reasons including f i n a l c las i f ier upset , erratic sludge r e t u r n , and i n a b i l i t y t o waste excess s ludge were respon- sible i n p a r t .

Nitrogen VS. Week: The n i t rogen p l o t s ind ica te a trend toward cons i s t en t n i t rogen removal which seems t o be independent of tempera tu re o r pH. ment i n opera t ional procedures, b u t no change i n t h e des ign.

The errat ic values ind ica te a need f o r r e f ine-

Ammonia VS. Week: This curve i n d i c a t e s a p o t e n t i a l f o r high ammonia removal. It a l s o seems t o indicate t h a t n i t r i f i c a t i o n and d e n i t r i f i c a t i o n maximizes dur ing t h e summer o r wa , rm water temperature period.

Fats , O i l s and Grease vs . Weeks This p l o t t i n g ind ica tes erratic primary and secondary removal, but a. very cons i s t en t o v e r a l l removal.

53

I SPRING I SUMMER FALL I WINTER 1 1

4 -

I

BREAK-IN *.-. BIOLOGICAL I PERIOD STABILITY

Figure 14. BOD l eve l s i n raw wastewater, a f t e r primary t r e i bment, and a f t e r total treatment. F i r a t sixty weeks.

5 4

-8- loo0F SPRING I SUMMER 1 FALL I WINTER I

I

1 8 j ' P

FLgure 15. Teaperatura and pH in the c a ~ r o w e l . F irs t sixty weeks.

55

loa

U 6 % \ P, n 0 m sc

1c

I:

1 .c

- \I

0 0.05

t a 0.02 - = . i 0.01. .

0 L 10- -

WEEKS

Food t o microorganismu r a t i o and relation- ship t o flnal BODS. F i r s t sixty weeks,

56

Figure 17. Average age of suspended s o l i d s in the car- Pou8Ol. F i r s t sixty weeka.

57

Figure 18. Suspended so l id s in the carrousel and sludge volume index. Firat sixty week$.

58

10,000

I

\

F

6

I

v) n - v) 1,000

W

z W

v) 3 v)

n n

n

1oc

I I r l̂- .. _ _ _ 1 --/--.-- __

I

Figure 19. Suspended solids i n rew wastewater; af ter primary treatment; and af ter to ta l treatment. Firs t sixty weeks.

59

A

I 1,

I I

I /

5 \ \ \

I \

0 10 20 WE E KS

Figure 2 0 , Nitrogen i n F&W wastewater; after primary treatment; and after total treatment. FLrat sixty weeks.

60

c 1 I I I - 1 1 E 1

L 5 1 ° F

1 10

Figure 21.

_. - I _ _ 40

_.. . - . I 20

WEEKS

. . - . __ _. 60

I 50

__ .... ..

Ammonia nitrogen in raw wastewater; and a f t e r t o t a l treatment. First s i x t y weeka.

61

T- lo,oooFF7--.7.--~---

Figure 22.

. -.

Fats, oils, and p e a s e in raw wahlteuater; a f t e r primary treatment; and a f t e r t c ta l treatment. First sixty weeks.

6 2

Figure2.3. Chromium v s , Week: The c h a r a c t e r i s t i c s of t h i s p l o t are s i m i l a r t o t h e previous Fa ts , O i l s and Grease curves. f i n a l e f f l u e n t is low and cons i s t en t .

Content i n t h e

Figure BOD vs % Frequency:

r e s u l t s would be better if the s o l i d s were f i l t e r e d from t h e samples p r i o r t o analyzing f o r BOD. t h e same f o r t he two special test per iods. about what they would be expected t o be.

Th i s se t of p l o t s i nd ica t e s good removal and 24, 25 o r s a t i s f a c t i o n of BOD as shown by t h e e f f l u e n t BOD a t S4. The

The e f f ic iency is seen t o be The va r i a t i ons are

Figure Suspended So l id s vs . % Frequency: t h i s se t of p l o t s is t h e r e l a t i v e l y poor removal of s o l i d s i n t he

The primary s ign i f i cance i n 26, 27

secondary c l a r i f i e r . than the des ign , w i l l u l t imate ly be cor rec ted , including i n a b i l i t y t o waste excess sludge on a set schedule because of clogging of r e t u r n pumps. This d i f f i c u l t y a l s o contr ibuted t o the high s o l i d s content i n t he f i n a l e f f l u e n t . t l i n g upse ts and s h o r t c i r c u i t i n g assumed t o be due t o changes which t h e u n i t could not handle. over 90410 and does not vary g r e a t l y with seasonal changes.

The MISS i n t h e ae ra t ion u n i t is much higher This w a s due t o a combination of reasons which

The secondary c lar i f ier w a s sub jec t t o set-

The ove ra l l p l a n t e f f i c i ency is

Figure SVI vs. p Freq uency:

changed somewhat from t h e f i rs t test period t o t h e second bu t the amount of MISS a l s o changed appreciably.

Suspended So l id s ( 4 % Vola t i l e ) vs . % Frequency: d i d no t i nd ica t e anything s i g n i f i c a n t except t o show t h e great v a r i a t i o n i n t h e primary e f f luen t and the cons i s t en t ly low MLVSS content i n t h e ae ra t ion u n i t , The low v o l a t i l e percentage can be assumed t o be due t o carryover of suspended s o l i d s from t h e primary sec t ion .

The cons i s t en t value of less than 100 in- 28, 29 dicates a very s t a b l e sludge condi t icn . The sludge condi t ion

Figure This se t of p l o t s 30, 31

Figure Nitrogen vs. % Freq uency: These p l o t s i nd ica t e one of t h e most 32, 33 important determinat ions of t h i s demonstration p ro j ec t , t h e a b i l i t y

of t h e secondary t reatment t o remove over 7@ of the t o t a l ni t rogen summer o r winter . occured i n the e f f l u e n t than dur ing the win te r test period, bu t t he o v e r a l l ni t rogen removal f o r t h e t o t a l p l an t w a s greater i n the win te r 9@ t o 84$, The erratic r e s u l t s were due t o opera t iona l trials, changes, and adjustments, bu t t he o v e r a l l a b i l i t y t o remove s u b s t a n t i a l amounts of n i t rogen can be seen. done on optimizing t h e operat ion through instrumentation i n order t o e l imina te opera tor con t ro l and e r r o r .

During t h e summer more n i t r a t e and less ammonia

More work must be

Figure TKN VS. % Frequency: This se t of p l o t s is very s i m i l a r t o t h e t o t a l 34, 35 ni t rogen p l o t s , Figures 15 & 24. When nitrates are present t h e

t o t a l n i t rogen includes them, as i n Figure 20, bu t they are not included i n t h e TKN. indicate the degree of n i t r i f i c a t i o n .

The TKN inc ludes NH3. It does not , by i tself ,

6 3

t-

I 0.1 L -.

0 I 60

I 50

I 40

I 30

- _.- - - -. - 2 0

1 10

i 1

1

f 4

i 1 i

WEEKS

Figure 23. Chromium Ln raw wastewater; af ter primary treatmaat; and af ter total treatment. First s i x t y weeks.

64

Is I /l /

1,000-

t

Figure 24. BO% l eve l s i n raw wastewater; after primary treatment; and after to ta l treatment.

65

Frequency Of Occurrence, 96 Figure 25. BOD5 levels i n raw wastewater; a f ter prim-

ary treatment; and a l t e r t o t a l treatment.

66

Frequency Of Occurrence, %

Figure 26. Suspended s o l i d s l e v e l s i n raw wastewater; a f t e r primary t reatment; and after Botal treatment

67

Frequency of Occurrence, %

Figure 27. Suspended s o l i d s l e v e l 8 i n raw wastewater; after primary treatment; and after t o t a l treatment.

68

40 I _ _-- L---I__I_ .--1_ 1 1.1..11111 80 90 95 98 99 99.5 L . i 0 .l 1 5 10 50

Frequency Of Occurrence, %

FLgure 28. Sludge volume index for carrouael activated sludge

69

Frequency of Occurrence, %

Figure 29. Sludge volume index f o r c a r r o u s e l activated aludge.

70

0 0.1

Figure

/- A

*/ e /

0

s2' *

1 5 20 50 80 90 95 98 99

Frequency Of Occurrence, % 30. Volat i l e auapended so l id s l e v e l s a f t e r primary

treatment, and i n the carrousel.

7 1

-----------I

/" 56

s2 / e

Frequency Of Occurrence, 70 Volatile suapended so l ids levels after primary treatment, and i n the eaFrouse1.

Figure 31.

72

2 5 20 40 60 80 90 98

Frequency Of Occurrence,% Figure 32. Total nitrogen levels is raw waate-

water; a f t e r primary treatment; and after t o t a l treatment.

73

t - 1

Frequency Of Occurrence, yo Figure 33. Tota l nitrogen l e v o 1 8 h a raw waste-

water; after primary treatment; and a f t er total treatment.

74

1,ooc

>r (P 0

loa - I

z w CJ 0 U I- z -.I X

-.I 10 W 3 Y

-

a n

1 .o

1

1 I

Frequency Of Occurrence - % Kjeldah.1 nitrogen l e v g l s in raw wastewater; af t er ppiraary treatmeat; and after t o t a l treatment.

Figure 34.

75

Frequency Of Occurrence - %

Figure 35. Kjeldahl nitrogen l e v e l s in raw wastowater; afCer primary Oreatment; and afOer total treatment.

76

Figure Ammonia vs. % Freq uencyr This graph indicates very good removal 36, 37 o r conversion of NH . It also i nd i ca t e s better e f f i c i ency dur ing

the summer test per 2 od. Figure Fa t s , O i l s and Grease (FOG) VS. % F’requencyr This p l o t shows con-

s i s t e n c y , good removal, and low e f f l u e n t concentra t ion. 38, 39

Figure Chromium VS. $ Frequency: set of p l o t s is t h e cons i s t en t ly high removal e f f i c i ency and the low f i n a l e f f l u e n t concentra t ion.

The m o s t important observation i n t h i s 40, 41

77

1,000 ---

I F

I

= 10

" E z * " t E E /'

Frequent? pf Opufrence - 2 Fiaure 36. ammon a eve EI n raw w stewater u - and after total treatment.

78

10(

1 s

0: - 2 5 10 20 40

I I .--~--- i _ -

60 80 90 98

Frequency Of Occurrence - 9/0 Figure 37. Ammorifa leve ls in raw waatewater,

and a f t e r total treatment.

7 9

10,OOl

1,ooc

tu Y - I

W cn W U (3

z

a

1 oc n a m-

0 a- I- a L

J I

10

1 .o

-3

4 !

Frequency Of Occurrence - % Figure 38. Fats, oils, and grease lerela in

paw wastewater; after primary treatment; and after total treatment.

80

Frequency Of Occurrence - Figure 39. F a t s , o i l s , and grease l e v e l r in raw

waatewater; aster primary tt-eatment; and a f te r to ta l treatment.

81

Frequency Of Occurrence - % figure 40. Chromium l e v e l s i n raw waatewater;

a f t e r pr imary tmatment; and a f t e r t o t a l Oreabment, expreeaed as Cr.

82

l- i

i-

0 d 5 I. 10 I - 20 1 - 40 J l l I I 60 80 90 I 98

Frequency Of Occurrence - % Figure 41. Chroaivrm levels €a raw warte water;

a f t e r primary Qmatment; anal a f t e r t o t a l treatment, expressed as Cr.

83

SECTION 8

CONCLUSIONS AND EVALUATIONS

CONCLUSIONS AS TO PARAMETER REMOVALS

The f i r s t ob jec t ive of t h i s demonstration g r an t w a s t o determine the e f fec t iveness of t h i s t reatment system i n f i n i t e terms. One of t h e p r inc ipa l f u r t h e r ob jec t ives w a s t o determine t h e effect of cold weather upon b a c t e r i a l a c t i v i t y i n t he secondary por t ion , marized t o show t h e t o t a l po l l u t an t removal e f f i c i ency of t h i s wastewater treatment p l an t while operat ing under summer condi t ions as w e l l as winter condi t ions , This summary follows:

The d a t a i n t a b l e s 8 and 9 has been sum-

TABLE 11. AVERAGE PERCENT OF POLLUTANT REMOVAL TOTAL TREATMENT* SUMMER AND WINTER TEST PERIODS

Po l lu t an t

% Removal Summer Winter

BOD^ Suspended s o l i d s

Ni t rogen- tota l

TKN

Ammonia

Fa t s , o i l s and grease

Chromium

99.1 80.9 94.7 94.1 96.4 90.0 99.0

97.6 84.1

83.5 87.4 74.6 99.0 98.8

"On b a s i s of d i f f e r ences between samples taken a t SI and S4.

It is evident from t h i s t a b l e t h a t winter operat ing condi t ions d i d reduce carbonanceous and nitrogenous b io log i ca l a c t i v i t y not iceably but substan- t ia l reduct ion continued t o occur.

BOD Remuva l s

Cold weather has a s u b s t a n t i a l effect upon many b io log i ca l wastewater t reatment systems i n lowering t he e f f i c i ency of BOD removal. I n t h i s s tudy

84

t h e average BOD r educ t ion du r ing win te r w a s only s l i g h t l y less than i n summer, I n a d d i t i o n , Table 9 r e v e a l s t h a t s i n g l e - d i g i t r e s u l t s i n mg/l were frequent ly achieved i n w i n t e r , t h u s i n d i c a t i n g e x c e l l e n t r e s i s t a n c e by t h e c a r r o u s e l de- s i g n t o atmospheric cond i t i ons w e l l below f r e e z i n g .

Table 11 shows i n excess of 97% removal of BOD r e g a r d l e s s of s easona l c o n d i t i o n s , The average r e s i d u a l BOD is shown by a n a l y s i s t o be on t h e o rde r of 6 mg/l. This is o n e- f i f t h of t h e u n o f f i c i a l EAT s t anda rd . Obviously t h i s wastewater t rea tment p l a n t is very e f f e c t i v e i n reducing b i o l o g i c a l oxygen demand.

Suspended S o l i d s Removal

Shor t of a n a c t u a l f r e e z e low temperatures would no t be expected t o be much of a d e t e r r e n t t o removal of suspended s o l i d s , Actua l ly t h e record shows t h e removals t o be a l i t t l e b e t t e r i n w in te r t han i n summer, but exa- minat ion of t h e data r e v e a l s t h a t temperature was no t a f a c t o r i n t h e i n c i - dence of r e s i d u a l suspended s o l i d s as d ischarged .

Table 12 shows suspended s o l i d s t o be i n excess of t h e u n o f f i c i a l BAT requirements . c lar i f ier , p l i a n c e seems t o be a t t a i n a b l e .

Terminal removal is dependent upon t h e e f f i c i e n c y of t h e f i n a l Obviously some a d d i t i o n a l f i n e tun ing w i l l be r equ i r ed bu t com-

N i t r i f i c a t i o n - D e n i t r i f i c a t i o n

The data shows t h a t t h e c a r r o u s e l is capable of suppor t ing n i t r i f y i n g

Ana ly t i ca l re- and d e n i t r i f y i n g b a c t e r i a , n i t r a t e s , and t h e la t te r conver t s n i t r a t e s t o free n i t r o g e n , s u l t s r epo r t ed i n Table 8 and Table 9 b e a r t h i s ou t . chemical ly i n t h e primary s e c t i o n , n i t r o g e n and o rgan ica l ly bound n i t rogen e n t e r i n g t h e c a r r o u s e l a t S2 were s u b s t a n t i a l l y reduced i n t h e d i t c h , more i n summer than i n w i n t e r . Table 9 a l s o r e v e a l s t h a t on some days du r ing w i n t e r ope ra t ion very low concentra- t i o n s of NH3-N and TKN did occur at S4, i n d i c a t i n g t h a t lower average n i t r i - f i c a t i o n a c t i v i t y i n w i n t e r may have been more a t t r i b u t a b l e t o occas iona l incidence of an unknown form of t o x i c i t y t han tempera ture .

The former conver t s n i t rogenous compounds t o

Some TKN removal occurs The t a b l e s c l e a r l y show t h a t ammonia

Conversion of n i t r a t e s t o n i t rogen is n o t only an i n t e r e s t i n g and perhaps unique feature of t h i s system b u t it a l s o has broad imp l i ca t ions i n t h e whole f i e l d of wastewater t rea tment . Support of d e n i t r i f y i n g b a c t e r i a seems t o be somewhat more d i f f i c u l t than t h a t of t h e n i t r i f y i n g s t r a i n . Addi t iona l s tudy toward e s t a b l i s h i n g a more s t a b l e environment f o r t h e s e organisms would c e r t a i n l y be worthwhile, D e n i t r i f i e r s were r a t h e r late i n developing du r ing t h e summer per iod b u t they were extremely a c t i v e and e f f i c i e n t du r ing the w i n t e r per iod . Later on, after t h i s g r a n t p r o j e c t w a s completed, t h e d e n i t - r i f i e r s were adverse ly a f f e c t e d f o r a time, bu t they have now r e t u r n e d . may have been sub jec t ed t o some form of chemical t o x i c i t y , o r perhaps the balance of aerobic/anoxic condi t ions w a s no t ag reeab le , Work is cont inuing t o g a i n f u r t h e r i n s i g h t .

They

85

F a t s , O i l s and Grease Removal

A s wi th suspended s o l i d s the removal of fats, o i l s and grease would

Average removal w a s a c t u a l l y a l i t t l e h igher i n w i n t e r than i n no t seem t o be very temperature dependent, and t h e r e s u l t s are cons i s t en t wi th t h i s . summer but it is no t poss ib le t o f i x t o t h i s any real s i g n i f i c a n c e .

I n comparison wi th u n o f f i c i a l 1983 BAT l e v e l s t h e average r e s u l t s are b e t t e r than requi red , with r e s i d u a l p o l l u t a n t i n t h e e f f l u e n t approximately 4% of t h a t allowable by BAT. 95% removal is achieved.

Chromium Removal

Chromium is probably t h e most important parameter, from t h e po in t of view of removal, of any of t h e components of tannery e f f l u e n t . Controversy exists as t o t h e relat ive t o x i c i t y of tannery chromium discharged, it exis ts e n t i r e l y i n t h e t r i v a l e n t form and as such is highly insoluble at pH's encountered i n a b i o l o g i c a l t reatment system, bu t many i n v e s t i g a t o r s are s k e p t i c a l and suspec t t h a t a por t ion may e x i s t as o r be converted t o t h e hem- va len t form which is highly t o x i c , at t h e r e s i d u a l l e v e l after primary treatment has never poisoned the b a c t e r i a i n t h e secondary o r l imi t ed b i o l o g i c a l a c t i v i t y i n 'any way, thus ind ica t ing r a t h e r conclusively t h a t it is a l l t r i v a l e n t , v i r t u a l l y inso lub le , and benign.

Actual ly

The exis tence of chromium i n t h i s system

The a n a l y t i c a l d a t a shows a high degree of removal, 9% on t h e average, both summer and winter . p e l t t h e average amount discharged is wi th in the BAT requirement.

I n terms of kilograms discharged per kilogram of r a w

SYSTEM EVALUATION AND DISCUSSION

The proposal f o r t h i s grant states on page 20, P a r t I V - h , Sampling and data c o l l e c t i o n procedures, t h a t methods f o r eva lua t ing t h e r e s u l t s of t h e p r o j e c t w i l l c o n s i s t of :

a. Evaluat ing t h e cha rac te r of t h e f i n a l e f f l u e n t i n terms of a t t a i n - ment of BAT requirements.

b . F ix ing t h e c o s t of operat ion while producing e f f l u e n t at BAT l e v e l s i n terms of :

Cents pe r f o o t of f i n i s h e d l e a t h e r product .

Cents per pound of f i n i s h e d l e a t h e r product.

Cents per pound of BOD p lus COD removed.

Cents per pound of suspended s o l i d s removed, compacted and placed at f i n a l d e s t i n a t i o n .

Cents per pound of n i t rogen removed.

86

The g r a n t amendment da ted August 23, 1976, added o the r means of evalua t ing the r e s u l t s . These are:

Page 5 A , item 3 C Include t h e c o s t i n cen t s per 1,000 ga l lons t r e a t e d ,

Page 5 A , item 5 The grantee s h a l l include a s e c t i o n which compares t h e demonstrated processes with o t h e r processes used f o r t h e same o r s i m i l a r purposes i n t h e tanning indus t ry and desc r ibe what changes i n des ign o r c o s t would be expected when applying t h e demonstrated technology t o a t y p i c a l ca t t le hide tannery. S p e c i f i c items t o be addressed are:

a. comparison on a cos t- e f fec t ive b a s i s of t h e LectroClear with a v a i l a b l e information on conventional primary t rea tment o r d i s - solved a i r f l o t a t i o n being u t i l i z e d by t h e indus t ry , o r wi th t h e p o s s i b i l i t y of no primary t rea tment .

b. comparison of t h e performance and o the r d a t a on t h e car rouse l wi th ava i l ab le information on the u n i t i n Ois terwi jk , Nether- l ands t r e a t i n g tannery wastewaters.

c. based on t h e demonstrated des ign c r i t e r i a and a v a i l a b l e information, make a prel iminary des ign and c o s t estimate f o r i n s t a l l - ing t h e system a t a t y p i c a l ca t t le hide tannery i n the U.S. t o meet t h e 1983 gu ide l ines .

I n t h i s s e c t i o n of t h e r e p o r t t he above s p e c i f i e d means of evalua t ion w i l l be d e a l t wi th i n t h e order of l i s t i n g , wi th t h e exception of item _Ec, which w i l l be d e t a i l e d i n a sepa ra te s e c t i o n , See Sect ion 9.

ATTAINMENT OF BAT REQUIREMENTS

The BAT requirements f o r 1983 ( u n o f f i c i a l ) axe compared i n Table 12 wi th t h e r e s u l t s obtained dur ing* summer and win te r opera t ing periods of t h e Winchester p r o j e c t . cept suspended s o l i d s , TKN i n t h e win te r , and fecal col iforms. The la t te r can be con t ro l l ed only by d i s i n f e c t i o n . Chlorinat ion has not been provided as a funct ion of t h e t reatment f a c i l i t y . Undoubtedly some ch lo r ine genera- t i o n occurs as a r e s u l t of e l e c t r o l y s i s i n both t h e coagulat ion c e l l and t h e f l o t a t i o n bas in bu t t h i s was no t evalua ted . cidence of col iform colonies dur ing t h e first t e s t period when e l e c t r o l y t i c a c t i v i t y w a s g r e a t e r . It is i n t e r e s t i n g t o note t h a t t h e average l e v e l of .40 kg of TKN p e r 1,000 kg of raw pelt i n t h e t r e a t e d wastewater during win- tertime condi t ions , while i n excess of BAT, r ep resen t s an 8% removal of TKN from t h e raw wastewater.

Compliance is achieved i n almost every category ex-

It may account f o r t h e lower in-

87

v3 c1 0

v3 a3 0

ch N 0

0

0 v3 rl

0

cl (v.

v3 0

0

D- 0

0

v3 0

0

5 0

0

0

cv rl

0

$ 5 .rl

1 u

88

I

I

I

I

v3 0 0

0

CJ 3-4 0

0

5 d 3 0

I m

I

0 0 0

b .b

I

0 v3 v3

5 m 0 FI

0 0 5-

rl E 0 0 rl \

H 0 k .rl rl 0 u rl

0 Fr

$

r l m cd -4

* $

COSTS OF OP&UTIOnT

One of the study objectives was t o determine the operating cos t s of producing t rea ted e f f l uen t a t BAT l eve l s i n terms of cents per foot of f in- ished l ea the r product, cents per pound of f in ished l e a t h e r product, cents per pound of BOD removed, cents per pound of suspended s o l i d s removed, compacted and placed a? f i n a l des t ina t ion , cents per pound of nitrogen removed, and cents per 1,090 gallons of wastewater t rea ted .

Operating cos t s f o r the 12-month study period were as follows:

Plant personnel - - - - - - - - - - - $46,860,68 Chemical suppl ies and e l e c t r i c i t y - - Repairs and equipment - - - - - - - - Total - - - - - - - - - - - - - - - -

78,301.20

8,423 . 00

$133,584.88

Production during the 12-month perid was:

Skins produced (dozen) - - - - - - - 58,466 2 Skins prodtlced ( f t ) - - - - - - - - 5,846,600

Cents per Foot of Ficished Leather Pr&uct

The cost of producing BAT l e v e l e f f l uen t per foo t of f in ished l ea the r pxxltlct is detemined as follows:

Operating cost/year - - - - - - - - - 2 Skins produced ( f t ) - - - - - - - -

Cost per square foo t of prcduct - - -

$133,58!+. 82 5,846,600

$ ,0228

Cents per Pound of Finished Leather Product

Cost of the BAT-level e f f l uen t per pound of f in ished l ea the r product is determined as follows:

Operating c o s t / y e a - - - - - - - - - $133, !34 Skins produced (dozen)- - - - - - - - 55,446 Averwe weight per dozen ( l b ) - - - - 24

Total weigh-L (lb) - - - - - - - - - - l,bO2,7Ob

Total cos t per pound - - - - - - - - $0 0?5 Cents per Pound of XLI Removed

Cost o f renoving BOD is determined as follows:

Operating c o s t / y e a - - - - - - - - - $133,5@I.*88 Operating days/yeax - - - - - - - - - Operating cost/day- - - - - - - - - - 250

$534

89

BOD removed/day ( l b ) - - - - - - - - - - - 2 , 050 Cost/lb BOD removed - - - - - - - - - - - $0 2.6

Cents per Pound of Suspended So l ids Removed, Compacted, and Placed at F i n a l Des t ina t ion

Cost f o r removing suspended s o l i d s , compacting them, and p lac ing them a t t h e i r f i n a l d e s t i n a t i o n is determined as fol lows:

Operating cost/day - - - - - - - - - - - - $534 Suspended s o l i d s removed/day ( l b ) - - - - 2,394 Cost/lb suspended s o l i d s removed - - - - - $ .22

Cents pe r Pound of Nitrogen Removed

Cost f o r removing n i t rogen is determined as fol lows:

Operating cost/day - - - - - - - - - - - - Nitrogen removed/day ( l b )

$534 272 - - - - - - - -

, Cost/lb n i t rogen removed - - - - - - - - - $1 -96

Cents pe r 1,000 G a l . of Wastewater t r e a t e d

Cost pe r 1,000 g a l of wastewater t r e a t e d is determined as fol lows:

Average d a i l y flow ( g a l ) - - - - - - - - - 301 ,ncn Operating cost/day - - - - - - - - - - - - $534 Cost/1,000 g a l wastewater t r e a t e d - - - - $ I -* 77

OPERATING COST OF MICROBUBBLE: GENERATION BY ELECTROLYSIS, DISPERSED AIR, AND DISSOLVED AIR.

Elsewhere i n t h i s r e p o r t it is s t a t e d t h a t t h e LectroClear e l e c t r o l y- t i c c e l l , as a primary source of microbubbles, was discontinued f o r two reasons ; an ino rd ina te amount of d i f f i c u l t y w a s encountered wi th maintaining e l ec t rodes i n t h e coagulat ion c e l l ope ra t iona l , and clear evidence was es tab- l i s h e d t h a t t h e e l e c t r o l y t i c genera t ion of microbubbles could not compete cost-wise wi th d ispersed air generat ion.

E l e c t r o l y s i s

The c o s t of opera t ion of t h e LectroClear e l e c t r o l y t i c c e l l , t h e o r i - g i n a l p r i n c i p a l LectroClear microbubble genera tor is determined as fol lows:

Design amperage requirement - - - - - - - 2,900 Design vol tage requirement (DC) - - - - - 6 Kilowatts requi red pe r hour - - - - - - - 17.4

90

Power cos t per kilowatt hour - - - - - - - Cost of power per hour - - - - - - - - - -

Cost per 1,000 gal lons - - - - - - - - - -

$0 035 $0.609

$ .034 Hydraulic flow rate (g$m)- - - - - - - - - 300

Dispersed A i r

The cost of operation of the dispersed air generator is detemined as follows :

Design power requirement (hp) - - - - - - 2

0 * 746 $0 035 $0.052

$0003

Kilowatts per horsepower - - - - - - - - - Power cos t per kilowatt hour - - - - - - -

Hydraulic flow rate (gpm)

Cost per 1,000 gal. - - - - Cost of power per hour - - - - - - - - - -

- - - - - - - - 300 - - - - - - -

Dissolved A i r ’* The estimated. cos t of operation of dissolved air f l o t a t i o n f o r t h i s

application, 300 gpm throughput with 507; rec i rcu la t ion f o r microbubble forma- t i o n is calculated as follows:

Design rate of flow (gpm)- - - - - - - - - Recirculation r a t e - 5@$ (gpm) - - - - - - Back pressure for air so lub i l i za t ion (p s i )

Required p u p

Kilowatts required per hour - - - - - - - Power cos t per KWH - - - - - - - - - - - - Cost of power per hour - - - - - - - - - - Hydraulic flow rate (am) - Cost per 1,000 gal lons - - - - - - - - - -

300

150 60

7 5 *2

$0.085 $0 182

$0.010

- - - - - - - - - - - - -

- - - - - - - 300

These calcula t ions show t h a t t he cost of e l e c t r o l y t i c generation of microbubbles is on the order of eleven times t h a t of dispersed a i r genera- t i on , Considering t h i s , along with less than adequate e lect rode r e l i a b i l i t y , leads t o r e j ec t i on of t he e l e c t r o l y t i c concept as a pr inc ipa l source of en- courwement t o f l o t a t i on . system designed t o provide microbubbles by means of dissolved air f o r f l o c f l o t a t i o n is i n excess of the cost determined by ac tua l operation f o r d ispersed air.

Likewise the calculated cost of operation of a

91

TABLE 13. COI\IPARISON OF COSTS OF OPEBATION OF SYSTENS TO PROVIDE ~IICROBUBBLES FOR A FLOTATION SYSTZPI

FOR SUSPiZNDED SOLIDS SDARATION

Xicrobubble generation mode

Cost of operation Per

1,000 ga l s treated

LectroClear

Dissolved A i r

Dispersed A i r

CONSIDEI?ATICNOF THZ POSSIBILITY OF EO PRIMARY TFfEATNZNT

The pos s ib i l i t y of el imination of primary c l a r i f i c a t i on , rznd depen-

The existence of a r e l a t i ve ly large amount of chromium i n the dence upon a biological treatment system plus a f i n a l c lar i f ier only has been considered. non-clarified wastewater as a substance po ten t ia l ly tox ic t o act ivated sludge bac te r ia has been a de te r ren t t o experimental by-pass of the primary sect ion. Other toxic chemicals which may be absorbed i n the agglomerated prec ip i ta tes i n the primary sec t ion and removed there are suspected of being present i n the raw wastewater a l so , which could i n t e r f e r e with bac t e r i a l a c t i v i t y i n the carrousel , although these were not i den t i f i ed i n t h i s study, Chromium and a l u m i u m hydroxides formed by pH adjustment t o 7.5 t o 8.5 t o remove them, as well as t o provide agreeable environmental conditions f o r bac te r ia i n the secondary, are gelatinous p r ec ip i t a t e s which do not rapidly se t t l e t o a reason- ably compact bottom sludge l aye r , emulsified fats and o i l s encountered i n the waste stream, led t o a laboratory bench scale t e s t i n g decision i n the design stage t h a t removal of the suspended solids introduced t o the system would best be removed by f l o t a t i o n , These considerations, i n addit ion t o the compaction feature provided by microbubbles continuously r i s i n g , r a i s i ng and dewatering the sludge blanket a top the f lo- t a t i o n basin, M adequately demonstrated the d e s i r a b i l i t y of m a x i m u m separa- t i o n of suspended so l i d s i n a primary c l a r i f i c a t i o n sec t ion p r i o r t o activated sl'udge treatment .

These facts, and the high incidence of

COMPARISON OF THE PERF'ORNWCE OF THIS CARROUSEL WITH ONE AT OISTERWIJK, XZTHiBLANDS l3

A f u l l scale carrousel has been i n operation at Oisterwijk, Nether- lands s ince 1973 t r ea t i ng tannery wastewater. The tannery is i n the category 1 c l a s s i f i c a t i on , chrome tan- hair burn, and is of medium s ize , processing not much more r a w hide weight (55,000 lb/day) than the Winchester tannery (43,200 lb/day green s a l t ed shear l ings) , d i r e c t proportion on a green hide o r skin weight bas i s t o the volume used a t Winchester (.350 m g d ) .

Water usage at 0,475 mgd is i n

Following is a t ab l e showing waste loadings t o the

92

Oisterwijk car rousel as wel l as the Winchester ca r rouse l , and the degree of removal of p o l l u t a n t s a f fec ted s i g n i f i c a n t l y by secondary t rea tment , BOD, NH3-N and t o t a l N .

TABLE 14. COMPARISON OF CARROUSEL TREATMENT EFFICIENCIES WINCHESTER, N . H . vs . OISTERWIJK, NETHERLANDS

Treatment In f luen t Ef f luen t Removal p lan t m g / l m g / l %

Winchester BOD5

Oisterwijk BOD5

W inchester-NH3-N

Oisterwijk-NH3-N

Winchester-total-N

Oisterwijk-total-N

317 1,100

32 264

107 408

6 20

5 248

12

270

98 98

84

6

89 34

The loadings t o the ca r rouse l at Oisterwijk are far greater than t o the ca r rouse l a t Winchester as shown above. This may be due t o removal of BOD and nitrogenous material i n t h e Winchester primary s e c t i o n , whereas it is the understanding t h a t the Oisterwijk treatment p l a n t does not have p r i - mary coagulat ion and c l a r i f i c a t i o n .

Comparison of t h e e f f i c i e n c y of each i n terms of removal of parameters c l e a r l y shows s u p e r i o r i t y of the Winchester operat ion. Fur ther proof of t h i s is demonstrated by quoting from a recen t ly issued DRAFT of an E.P.A. d e v e l o p ment document f o r the l e a t h e r tanning and f i n i s h i n g i n d ~ s t r y ? ~ Inves t iga to r s who prepared t h i s document s t a t e , on l i n e s 6863 through 6866, "This ( ana lys i s of d a t a ) i n d i c a t e s t h a t t h i s (Winchester) a c t i v a t e d sludge system produced b e t t e r r e s u l t s than the Netherlands (Oisterwi j k ) app l i ca t ion , including demonstration of i n s e n s i t i v i t y t o win te r temperatures i n removal of carbonaceous oxygen demand (BOD5) and nitrogenous oxygen demand (ammonia) by n i t r i f i - cat ion ."

The Oisterwijk app l i ca t ion , according t o a n a l y t i c a l data a v a i l a b l e , w a s not very e f f e c t i v e i n n i t r i f i c a t i o n and d e n i t r i f i c a t i o n . Experience a t Winchester at times o t h e r than t h e demonstration periods has shown t h a t de- n i t r i f i c a t i o n i n p a r t i c u l a r is a s e n s i t i v e process. t h a t t h e Oisterwijk f a c i l i t y w a s not being operated wi th any emphasis upon nitrification-denitrification at the time t h e above d a t a was recorded. More operat ing background and understanding is needed t o f u r t h e r e s t a b l i s h relia- b i l i t y at high l e v e l s of nitrification-denitrification.

It is a l s o poss ib le

93

SECTION 9

UPLLCATION OF THE SYSTEM

TO

CONSIDEBATION AND COWAHISON OF PHOCESSgS

Three of the seven ca tegor ies of t anner ie s r e l a t e t o f u l l - s c a l e c a t t l e - hide processil-,g - including h a i r removal, tanning, color ing and f a t l i q u o r i n g , and f i n i s h i n g . h a i r and chrome tan, (2) s ave h a i r and chrome tan, and ( 3 ) save h a i r and vegetable t a n .

The three ca tegor ies are c a t t l e h i d e t anner ie s t h a t (1) pulp

Few if any chrome t anner ie s save h a i r . t o soak, wash, and hair-burn using s t rong sodium s u l f i d e l iquors . Most tan- n e r i e s operat ing t h i s way reclaim s u l f i d e l i q u o r s and separa te pulped h a i r s o l i d s from those so lu t ions , d i r e c t i n g the s o l i d s t o l a n d- f i l l , t hus keeping as much as poss ib le of those materials out of the waste stream. Similar ly systems have been developed by most chrome tanners t o conserve chromium by p r e c i p i t a t i o n and reuse o r by recycl ing of chrome t a n l i q u o r s , and most are conscious of the need f o r water conservation, not only from t h e po in t of view of i n i t i a l c o s t , bu t i n cons idera t ion of the e f f e c t s of wasteful d i l u t i o n , and the hydraulic load c o s t of d i sposa l and sewerage t rea tment ,

More and more the mode has been

In a d i f f e r e n t but similar manner most vegetable t anner ie s employ a h a i r save process. This system uses much less s u l f i d e and produces a valua- b l e by-prduc t i n the form of c a t t l e h a i r . Not unlike chrome tanners , vege- t a b l e L ~ . L : I ~ ~ S have been able t o reduce o r e l iminate some process s t e p s which formerly required much water.

The n e t r e s u l t of these in- plant a c t i v i t i e s has been t o reduce high potency waste l i q u o r s t o l e v e l s which are no t s o d i f f e r e n t from those encoun- te red a t the shea r l ing tannery. Because a shea r l ing tannery is not t y p i c a l , s ince it does not process c a t t l e h i d e and has no beamhouse, t r a n s f e r of iden t i- cal wastewater treatment technology is no t poss ib le . Nevertheless, very real similarities d o exis t i n the na ture of the respect ive tannery d ischarges , which lead t o specula t ion t h a t adapta t ions should be explored.

94

COMPARISON OF WASTEWATERS

In order t o r a t h e r de f in i t e ly e s t ab l i sh the s imi l a r i t y the fol loxing t ab l e of typ ica l analyses of wastewater from these A. C . Lawrence tanner ies , a l l of which are considered t o be more o r less representa t ive of complete t inning operations i n t h e i r respective categor ies are presented.

TABLE 15. TYPICAL TANNEBY WASTEWATER ANALYSES

Parameter

Category 1 Category 3 Catel;o;ry 7 Cattle hide Catt lehide Shemiings Chrome tan-pulp kxir Veg b e h a i r Chrors tan South Pa r i s , Maine Haeelwocd, N.C. Winchester

mg/l mg/l mg/1 -

BOD. 686 812 Suspended s o l i d s 2 , 718 1,080 1,150 Total s o l i d s 5,620 5 , 314 14,000

Calcium-Ca

Fats , o i l s , greases

PH Chromium-Cr

Ammonia-N

64.9 580

187 14

10.9

550 400*

201 4-50

99 73 32

9 .9 5.1 -

TKN-N 126 179 75 Volume-mgd 0.8 0 .3 0.3 Raw hide o r pelt lb/day 130,000 52, ooo 41,500 Water usage-gal/lb hide 6.1 5.8 6.9

*Added at treatment p lan t

Examination of t h i s t ab le shows that there is a remarkable s imi l a r i t y i n the nature of the w a s t e w a t e r from each. The volumes are not the sanie, of course, but the s ign i f ican t d i f ferences i n pol lutant s t reng ths are on the order, f o r the most pa r t , of about 2X. Total volume is considerably greater f o r the s i de l e a the r tannery s ince t h i s is a function of capaci ty , f igure of 14,000 m g / l f o r t o t a l s o l i d s i n the Winchester column r e f l e c t s the very large comparative amount of curing salt i n and on a raw pel t or entrapped i n the wool, and the use of long br ine f l o a t s i n paddle p i t s while processing shear l ings as opposed t o sho r t brine f l o a t s i n drums f o r hides.

The

It seems i n order then, t o take the stance t h a t t h i s treatment system, with some modifications, is su i t ab l e f o r any tannery, One of the requirements of t h i s demonstration pro jec t is t o prepare a preliminary design and cos t estimate f o r a system sui table f o r a t yp i ca l U.S. ca t t l eh ide tannery t o meet 1983 BAT guidelines. This exercise w i l l include a system f o r a chrome

95

tan- pulp h a i r ca tegory 1 tannery , and a system for a vegetable tan- save h a i r category 3 t annery . Since A . C , Lawrence Leather Company ope ra t e s and has i n t ima te knowledge of f a i r l y t y p i c a l t a n n e r i e s process ing c a t t l e h i d e s i n both of t h e s e c a t e g o r i e s those t a n n e r i e s w i l l comprise t h e b a s i s f o r t h e des igns .

Comparison of parameters , as i n Table 15, seems t o impart v a l i d i t y t o t h e s ta tement t h a t t h e only apparent d i f f e r e n c e s between wastewater a treatment f a c i l i t y s u i t a b l e f o r a hide tannery , and a s h e a r l i n g t anne ry , would be: (1) s i z e , (2) provis ion f o r i n i t i a l sedimentat ion t o remove some of t h e heavy bearnhouse and tanhouse s o l i d s before in te rmixing t h e two streams and ( 3 ) , proper b u i l t - i n precaut ion , p a r t i c u l a r l y i n t h e case of t h e chrome-pulp h a i r t annery , t o c o n s i s t e n t l y main ta in t h e pi-i i n t h e mixed beamhouse-tanhouse l i q u o r above 8.5 t o prevent evo lu t ion of hydrogen s u l f i d e as an obnoxious and perhaps p o t e n t i a l l y l e t h a l gas . i n t h e des igns .

These cons ide ra t ions are incorpora ted

96

PLANT FOR A CIiROIX

TAnT-P'JLP iiAIi? CATSGORY 1 CATTLL3HII)ii TAhNERY

This exercise is addressed by expanding t h e d e t a i l e d information on the i l inchester t reatment p lan t components as presented i n Section 3 of t h i s r e p o r t , and- cos t information f o r t h e complete system presented as Appendix E. Two r e p o r t s , e n t i t l e d "Supplemental Report. on Combined Wastewater Treatment F a c i l i t i e s , P a r i s U t i l i t y Distr ict , South P a r i s , Laine" by Whitman and Howard, h c . Boston, Lass. and t h e o ther , "Activated Sludge Treatment of Chrome Tan- nery Uastes" by A , C. Lawrence Leather Co,, South P a r i s , Iliaine, F.W.P.C.A. Publ ica t ion ORD-5 are used f o r background information i n developing the chronie-tan pulp h a i r prel iminary des ign, Co'sting of components is est imated by comparing flows and parameter loadings at South P a r i s and Winchester where appl icable , and a r r i v i n g at a reasonable es t imat ion . made t o provide engineering des igns or obta in equipment or const ruct ion con- t r a c t o r s b ids for any i t e m . Costing of concrete cons t ruct ion has been e s t i - mated by examlnation of c o s t s presented i n the above documents, and has been detemdned t o be about $&.OO per cubic f o o t of t o t a l tar& volume, a f t e r u p d a t i n g 1974 and 1976 p r i c e s by compounding a t @: p e r year .

No attempt has been

See Fib- 42 f o r schematic diagram.

97

a

I -X Z O u m t;o= Z U O W V I

0 W

a 4: W -I V 0

I- a

s

-I V

98

Basic Design Parameters - Chrome Tan, Fulp-Hair :sibi'l?P

'rota1 flow (m&) - - - - - - - - - - - - - - 0.8

Beamhouse flow (m@) - - - - - - - - - - - - - - 0.575 Tanhouse flow (mgd) - - - - - - - - - - - - - - 0.225

Treatment p l a n t opera t ing day ( h r s )

lQualized beamhouse flow (gpm) - - - - - - - - 479

P o l l u t a n t loadings - see Table 15. - - - - - - 20

Equalized tanhouse flow (gpm)- - - - - - - - - Total equalized treatment p l a n t operat ing

200

679 flow ( gpm) - - - .. .- - - - - - - - - - Design and Cost dst imation of Components

C uarse E creen ing 1

This is not r iecessari ly a p a r t of a treatment system per se, Coarse screening at the po in t the e f f l u e n t stream emanates from the tannery is es- s e n t i a l whatever the d e s t i n a t i o n may be, f o r p ro tec t ion of t ransmission l i n e s if nothing else. Therefore, t h i s item is no t being included as such, bu t provision f o r removal of s o l i d s which can be separated by simple sedimenta- t i o n is included i n t h e plans f o r the a l k a l i n e and acid wastewater holding tanIcs,

R a w iistewater Pumps

These are needed only i n the event t h a t grades are no t adequate f o r g rav i ty flow, and are r e l a t e d t o t ransmission r a t h e r than treatment. I n most cases the holding tanks can be located below grade i f necessary, and the constant flow purnps w i l l provide whatever e l eva t ion is needed.

Iiolding and Xqualizing Tanks

The wastewater flow f ron 5i.e ta-rx?ry a r r i v e s at the treatment p l a n t i n two streams, Leainhouse flow tihich is highly a l k a l i n e because of its lime and sodium s u l f i d e content , and tanhouse flow which is a c i d i c . 30th flows are e r r a t i c because each is dependent upon batch operat ion dumps. flows may contain suspended s o l i d s i n s i z e s ranging f ron f'i e t o gross . In view of d i f f i c u l t i e s encountered with entrained ment p l a t s where t h e i r presence was no t s u f f i c i e n t l y recognized dur ing the design stage, it is considered e s s e n t i a l t o include s o l i d s removal i n the holding and equal iz ing tanks for each waste s t r e a n i n t h i s exercise. This s t e p w i l l he lp t o a l s o br ing the cha rac te r of the combined flows more i n t o l i n e wi th the s i n g l e Winchester tannery e f f l u e n t stream by i n i t i a l l y removing an appreciable amount of undissolved lime. over- all holding capaci ty a s designed for South P a r i s and found t o be adequate i n p r a c t i c e , but include t r a v e l l i n g bottom scrapers i n the major por- t i o n of each t o d i r e c t sedimented s o l i d s t o a sludge w i t h d r a w a l well a t the en te r ing end, very s i m i l a r t o a standard rec tangular ca tch basin.

Also both

solids at e x i s t i n g treat-

The tanks have the sane

99

Cemhouse flow holding, equal iz ing , and c l a r i f y i n g tank

This tank is envisioned t o be of concrete, rectangul.ax, and is d i- vided i n t o two s e c t i o n s by a w a l l loca ted two t h i r d s of t h e t o t a l l eng th of the tanlr from the en te r ing end. t o the bottom, with a three inch hor izonta l opening i n the w a l l a c ross the f u l l width of the tank, two feet from t he bottom of the tank. ta l s l o t opening al lows flow t o pass Prom t h e f i r s t seckion i n t o the second sectiori wnwe the constant flow head box is located , whi l s t minimizing back- passage of turbulence and discouraging wash-through of s o l i d s a t times when the l i q u i d l e v e l may be low. The afore~~ient ioned sc raper f l i g h t s are located i n the first sec t ion , t r a v e l l i n g i n the direc.tion counter t o flow ac ross the bottom, thence v e r t i c a l l y upward t o near t h e t o p of the tank, hor i zon ta l ly i n the d i r e c t i o n of flow across the t o p of the tank, and v e r t j x a l l y downward t o the be,inning. In order t o avoid excessive l eng th f o r t h e wooden f l i g h t s the width of the tank should not exceed twenty fee t ,

The w a l l extends from the t o p of %he tank

This horizon-

Design parameters

Detention t h e (I-) - - - - - - - - l l idth of tank - s e e above ( f t ) - - - - - - - - I ; l t t x 20

- - - - 10

Beamhouse flow (mgd) - - - - - - - - - - - - - - 0.575

Siz ing and s p e c i f i c a t i o n s

Construction - concrete

Voluiie - 239,000

Volume (ft 3 ) - - - - - - - - - .. - - - - - - 32,000

;{idth (ft) - - - - - - I - - - - - - - - - - Lellgth (ft)

10 x 575,000 (gal) - - - - - - - - 7 *5 Constai t-gal /f t 3 - - - I - - - - - - -

20

100

16

$8.00

- - - - - - - - - - - - - - - Depth (ft) - - - - - - - - - - - - - - - -

Cost est imate

Zstimated u n i t c o s t - see above ( f t 3 )- - - - 3 Volwne ( f t ) - - - - - - - - - - - - - - - - 32,000

Construction c o s t - - - - - - - - - - - - -$256, ooo To ta l c o s t including sedimentation

equipment j e s t ) - - - - - - - - - - - - $275 000

Tanhouse flow holding, equalizing, and cbriFjizg tank

This tank is a l s o e n v i s i o i i d as beir_g constructed of concrete, rec- t a n g d a r , wid of the same t o t a l concept as t h e Leanihouse flow tank, except t h a t it is smaller, and the second s e c t i o n would not conta in a constant flow head box, but would be the loca t ion of t he tannouse wastewater flow purnps.

100

10

0.225 ma.x 29

94,000

12,500

7 05

20

16 40

h

$8 .oo J Gstimated u n i t c o s t ( f t ) - - - - - - - - - - - Volume (ft 3 ) - - - - - - - - - - - - - - - - - 12,500

$100,000 Construct ion c o s t - - - - - - - - - - - - - - - Tota l c o s t including sedimentation

equipment (est)- - - - - - - - - - - - - - - $115,000

Constant Flow Quipment

The concept of constant flow through the treatment system w a s incor- porated i n t o the des ign of the iirinchester, W.W,T,P, Pumps i n the holding tank e l e v a t e wastewater t o an overflow weir box of special design (see Sectiori 3), from whence it flows t o and through the system a t a constant rate. This mode of operat ion s i m p l i f i e s process con t ro l s i n c e a l l of the coinponents of the primary treatment s e c t i o n operate i n unison without adjustment f o r flow v a r i a t i o n s . The primary s e c t i o n opera tes e i t h e r al l- on o r a l l - o f f , depending upon t h e a v a i l a b i l i t y of e f f l u e n t t o be t r e a t e d , thus allowing constant s e t t i n g s f o r dosing pumps aid the d ispersed air microbubble genera tor , and e l iminat ing weax and t e a r when flows are low o r non-existent, The on-off con t ro l is provided i n t h i s s i t u a t i o n through l e v e l sens ing switches located i n the beamhouse flow holding tank, which a c t i v a t e o r i n t e r r u p t the cons tant head sspply punps and t he tanhouse flow pumps according t o the a v a i l a b i l i t y , i n t h i s case, of a l k a l i n e tannery e f f l u e n t ,

101

Constant flow l ied box

See Sect ion 3 Design parameter

Eiorizontal c ross sec t ion (gal/ft2/uiiri) - - - - - - - 32

Total volume of beanhouse f low ( e @ ) - - - - - - - - 575 ? 000

Design t reatment p l an t operatirig day ( h r ) 20

EIOW rate through weir box (gprri) - - - - - - - - - - 479 15

Diameter ( f t) - - - - - - - - .. 4.5 9 Gepth (f t) - I - - - - - - - - - - - - - - - - - - -

Siz ing of vesse l

- - - - - 2 Cross s e c t i o n a l area needed 3 32 g a l / f t / n i n - (f t2)

- - - - - - I - -

Cost es 2; imate

Constant flow qupply pumps - beanihouse flow holding 'tank

These are submerged punips t o be loca ted near the bottom of the beamhouse flow holding t m k a t the end opposite from the flow ent rance , e l eva te the beaihousc wastewater t o the constant- flow head box arid thence i n t o the treatment system, cluded here t o avoid in"ierruption i n case of s i n g l e pump f a i l u r e .

They

Two pumps, each capable of supplying f u l l flow are in-

Tanhouse Mastewater Flow Pumps

Tanhouse rcraste w i l l be co l l ec t ed i n the tanhouse flow holding tank and dispensed therefroill a t a constant rate as long ils a l k a l i n e waste is ava i l ab le u r h s s h t e r rup tec i by the pH sensing device located i n the main flow l i n e dotrzstreani of the c o m i a n t flow head Lox, s i g n a l l i n g t h a t the danger condit ion ~f yi. 9 .C is L C in(- approa,ched. It is est imated t h a t the constant florr r a t e LOI this nm,mrinl. > i i l l be 200 Gpm, which would dep le t e the design supply i n 18.75 hou-s, slightly sooner thaii the des icn supply of a l k a l i n e beanihouse waste €ror: the bcanihousc fjow hold ing -tank. Actual p rac t i ce o r p i l o t p l an t

1 0 2

work might d i s c l o s e t h a t a h igher r a t e of ac id waste flow could be t o l e r a t e d but it seeins .i;iiportant t o have the two waste stream become exhausted a t about the sanie time. Two pumps, each capable of supplying f u l l flow a r e speci f ied here, as i n the beamhouse l i n e , t o avoid i n t e r r u p t i o n i n caSe of s i n g l e pump failure

Design parameter ~ l o i j rate (gpm) - - - - - - - - - - - - - - - - - - - -

Capacity - each (gpm) - - 200

Siz ing and s p e c i f i c a t i o n - - - - - - - - - - - - - - 200

Hanufacturer - Flyght Corp . Norwalk, Conn .

rkdel No - 4 - CP - 3105

5 R P M - - - - - - - - - - - - - - - - - - - - - - - 1,750

Plvllps - 2 $1,000 each - - - - - - - - - - - - - - - - $2,000

IGotor HP - - - - - - - - - - - - - - - - - - - - -

Cost estimate

pH Sensi.ng f o r Acid Vaste Flow Control

A s noted i n the foregoing t h i s sensor would funct ion only as a safe- guard q a i n s t development of an ac id condi t ion i n the mixed wastewater flow.

Design p a r a i e t e r s pH range - - - .. - - - - - - - - - - - - - - - - 7.5 t o 11 Power i n t e r r u p t i o n l e v e l (pH) - - - - - - - - -

Spec i f i ca t ions 3 00

Manufacturer - Beckman Instrument Co.

Fiodel No. - 940 pH analyzer

Cedar Grove, N. J ,

Specia l feature - dead band @ pH - - - - - - - 8.0 t o 9.0

$1,500 Remote sensor connection - 150 f t . - - - - - - - - 200

$1 , 700

Cost estimate b s t r m e n t - - - - - - - - - - - - - - - - - - - - Tota l - - - - - - - - - - - - - - - - - - - - -

Dosing Pump - A l u m

A l u m is used t o develop agglomerated f loccu la t ion which not only a i d s i n entrapping and removing f i n e l y divided suspended s o l i d s , but also a i d s i n en- trappirig microbubbles t o enhance f lotat i .Cn. The a l u m is purchased and used i n 45% w t . s o l i d s s c l u t i o n , sp . gr. 1.330.

103

http://flotati.Cn

De s ign parariie t e r 1,000 mg/!Lto be added t o combined beamhouse-tanhouse flow

Aqualized bemhouse flow (gpm) - - - - - - - - - - - - - Equalized tanhouse flow (gpm) - - - - - - - - - - - - - Tota l equalized flow (gpm) - - - - - - - - - - - - - - Weight of flow ( lb /ga l ) - - - - - - - - - - - - - - - Weight of flow (lb/min) - - - - - - - - - - - - - - - Veight of alum d 1,000 mg/l(lb/min) - - - - - - - - - Weight of s tock alum s o l u t i o n needed @ 45;: s o l i d s ( lb )

Weight of s tock alum s o l u t i o n ( lb /gal ) - - - - - - - Volume of s tock alum s o l u t i o n needed (gym) - - - - - Pump capaci ty needed (gpm) - - - - - - - - - - - - - f4anufacturer - Liqu i f lo Equipment Co.

S e r i e s 34 3 gpm T i n . 316 5s

Siz ing arld pump s p e c i f i c a t i o n

Warren, N . J . 1

Motor ~p (UC) - - - - - - - - - - - - - - - - - - Speed - var iab le . I l iax rpm

Cost estimate Pump and motor - - - - -

D ikpersed A i r Generator

See Figure 5. Microbubbles are used t o prov

479

679

5 8 770

200

8.5

5.77 12.82

11.1 1.15

- + 1.15

0 075 1, 725

$250

de f l o t a t i o n f o r the suspnded s o l i d s removal p r i n c i p l e used i n t h i s t k a t m e n t system. expensive means f o r providing the same, see sec t ion 8.

Dispersed a i r is the least

Design paramter

F t 3 of air /100 g a l of flow - - - - - - - - - - - - - 0 0 . 5

Tota l equalized flow rate (gpm) - - - - - - - - - -- 679 S iz ing and s p e c i f i c a t i o n s .

Iknufac tu re r - Greey Corp.

hodel No. 6 - LBC - 300 316 SS

Toronto, Canada

Motor Hp - - - - - - - - - - - - - - - - - - - - - Cost estimate

Generator wi th motor, complete - - - - - - - - - - 104

3

$4,500

Coagulation C e l l

See Figure 6.

This u n i t is used t o provide de ten t ion time t o allow microbubbles and suspended f l o c t o become in t imate ly associa ted , thus enhancing f l o t a t i o n .

Design parameter

Effec t ive residence time 2 minutes

S iz ing and spec i f i ca t ions .

To ta l equalized flow rate (gpm) - - - - - - - - - - - C e l l volume required f o r 2 min, flow (gal) - - - - - C e l l volume required f o r 2 min. flow ( f t ) - - - - - Diameter of t o p s e c t i o n ( f t ) - - - - - - - - - - - - Depth of t o p s e c t i o n ( f t ) - - - - - - - - - - - - - - Width of bottom s e c t i o n ( f t ) - - - - - - - - - - - - Length of bottom s e c t i o n ( f t ) - - - Depth of bottom sec t ion ( f t ) - - - - - - - - - - - - Manufac-turer - Local s h e e t nietal f a b r i c a t o r

3

- - - - - - - -

679 1,358

181

7.5 2 *5 8,0

a .o 2 .o

Cost es t imate

Same as 1976 updated @ 8$ per year (est) - - - - - - $10,500

Dosing Pump - Polye lec t ro ly te

This pump is used t o continuously add about 12 d l of po lye lec t ro ly te i n 0.2$ s o l u t i o n t o t h e waste stream t o aid f loccu la t ion and f l o t a t i o n ,

Design parameter

12 mg/lto be added t o combined flow.

Po lye lec t ro ly te so lu t ion s t r e n g t h - 0 . 8

Siz ing and s p e c i f i c a t i o n s .

To ta l equalized flow rate (epm) - - - - - - - - - - - Weight of flow ( lb /gal ) - - - - - - - - - - - - - - - Weight of flow (lb/min) - - - - - - - - - - - - - - - Weight of po lye lec t ro ly te needed 8 12 m g / l (lb) - - - Solut ion s t r e n g t h (7:) - - - - - - - - - - - - - - - - Weight of s o l u t i o n needed/min ( l b ) - - - - - - - - - - Factor - lb /ga l (3 SI), gr. 1.015 - - - - - - - - - - - Volume of s o l u t i o n needed (gpm) - - - - - - - - - - -

679

5,700

a .4

0.068

0.2

314

8 *5 4

105

Pump capac i t j Eecded (gpm) - - - - - - - - - - - - - 14

P;a,nuTacturer - Liqui€lo Zquipnent Co.

Se r i e s 36 5 gpm 3/4 i n . 316% I.Iokor (11p) - - - - - - - - .. - - - - - - - - - - - - 0 . 7 9 C

Variable speed, is ‘,-2:; q m iiiax.

Cost e s t irnatc

Pump and inotor (es t ) - - - - - - - - - - - - - - - - $300

Bubble Classifier

See Figure ‘7

This u n i t is an open top, r ec tangula r , s teel tank through which the waste stream is passed, a f t e r in t roduct ion of microbubbles, t o allow oversize bubbles t o escape before en te r ing the f l o t a t i o n bas in . Ia.rge bubbles d i s r u p t the f l o a t i n g sludge blanket at the e n t e r i n g end of the LectroClear tank.

Cost; estimate

Tank complete (est) - - - - - - - - - - - - - - - - $750

LectroClear S o l i d s F lo ta t ion Basin

See Figure 8 For d e s c r i p t i o n see Sect ion 3 Design parameters

Surface area - ft2/100 gpm - - - - - - - - - - - - 100

15 20 20

Vertical c ross e c t i o n perpendicular t o d i r e c t i o n 2 Width - maximunl (ft) - - - - - - Electrode dens i ty - number/100 C1;pIn - - - - - - - -

of flow - f t /IOO gpm - - - - - - - - - - - - - - - - - - - -

106

Sizing and spec i f i ca t io r i s

Total equalized flow rate (gpm) - - - - - - - - - - - C?9 A r e a of v,y-ticx.l crcss-sect ion

Depth of vesse l , s a y ( f t ) - - - - - - - - - - - - - - iiidth of vesse l ( f t) - - - - - - - - - - - - - - - - - Surface area GI 1.00 f t /IOO gpm (ft ) - - - - - - - - - hn i , l i , (1: vc:;sel (~t) - - - -

102

6 I?

679

2 3 15 ft / loo gpm (ft ) I - - - - - - - - - - - - -

2 2

- - - - - - - - I - - - 40

>:anufac turer - Local machinery f a b r i c a t o r

Cost es tirriate

Cost of Ainchester LectroClear (1976) - - - - - - - - $31,200

535 , 000 2,100

Up5iaLe €or 1978 3 8,4per year - - - - - - - - - - - - volume of a inches te r u n i t ( f t 3 ) - - - - - - - - - - -

3 Volume o€ u n i t s i zed as above ( f t ) - - - - - - - - - Conparative s ize (x) - - - - - - - - - - - - - - - - Corqmrative cos t of u n i t (1978) - - - - - - - - - - - Cost o€ electrodes, each - - - - - - - - - - - - - - Total c o s t of electrodes - - - - - - - - - - - - - - Total co s t OP f l o t a t i o n bas in , i n s t a l l e d (est) - - -

4,080

1.94 $67,900

136 $95

Zlec-brales needed - - - - - - - - - - - - - - - - -

$12,920

$80,820

Current Rectifier

Di rec t cur ren t is required f o r microbubble generation by e l e c t r o l y s i s i n the LcctroClear f l o t a t i o n bas in ,

Design parameter

2,600 amperes at 7 v o l t s , U.C.

S iz ing and s p e c i f i c a t i o n s

Manufacturer - Oxymetal I n d u s t r i a l Corp. , Warren, IIich.

idcdel - Udali te No. 4 idDV-5000

Type SASS e 460V Water cooled

Cost estimate

Xinchester co s t (1976) including switches and wiring, i n s t a l l e d - - - - - - - - - - - - - - - $10,500

$12,250 Estimated t o t a l co s t ugdated t o 1978 - - - - - - - -

10 7

Skimmings Pump

Floated s o l i d s i n the LectroClear u n i t are skimmed off and d i r e c t e d i n t o a receiv ing tank, see f i g u r e 8, from which they are Turiperi -to s1i;dge holding tanks.

Design parameters

Open impel ler t r a s h pump des ign.

Capacity 2 times Winchester u n i t .


PIanufacturer - Gorman Rupp Co.

4 inch in take , 3" discharge

1-lotor 3 HP, 1750 rpm, d i r e c t connected

Cost est imate pump, i n s t a l l e d - - - - - - - - - - - - - - - - - $1,500

Sol ids S lu r ry Pumps

So l ids separa ted by sedimentation i n the two holding tanks have t o be t r ans fe r red t o the sludge holding tank t o be compacted along with skimmed s o l i d s from the LectroClear and wasted s o l i d s from the car rousel . These w i l l be ac t iva ted by t imers. f i e r , beamhouse and tanhouse, and a t h i r d f o r a spare . s tandardiza t ion c a l l s f o r speci fy ing three a l i k e .

Three pumps a r e needed, one a t each i n i t i a l c l a r i - The advantage of

Design paraineters

Vaughn choy3er pimps

Corrosion r e s i s t a n t cons t ruct ion


To ta l volume of beamhouse flow (mgd) - - - - - - - - - Suspended s o l i d s removed by sedimentation ( m g h ) (est)- Constant ( lb /gal ) - - - - - - - - - - - - - - - - - -

Weight of suspended s o l i d s removed (lb/day) - - - - - 2,445 Weight of s o l i d s s l u r r y b 1% s o l i d s (lb/day)- - - - - 244,500 Constant (Ib/gal) - - - - - - - - - - - - - - - - - -

0 *575

8.5 500

Weight of beamhouse flow (l'o/day) - - - - - - - - - -4,887,500

8 .j Average purnping rate d 20 hr. day (gpm) - - - - - - - 24

Tota l v o l w ~ e of tanhouse flow (mgd) - - - - - - - - - Suspended s o l i d s removed by sedimentation (est) (mgh)

0.225

1-r-00

Weight of tanhouse flow (lb/day) - - - - - - - - - - 1,912,500

108

Meight of suspended s o l i d s rernoved (lb/day) - - - - ideight of s o l i d s s l u r r y U 1% s o l i d s (lb/day)- - - - Weight of s l u r ry ( I b l g a l j - - - - - - - - - - - - - Volme of tarlhouse flow s o l i d s s lu r ry (g@) - - - - Average pumping rate 8 20 h r . day (gpm) - - - - - -

Rum’uer of pumps requi red - 3 Manufacturer - Vaughn Co., Inc.

Montesano, Wash . Model 150. Motor 5 HI?, 1,750 rpm

Interchangeable

760 76,000

8,950

8 .5

7.5

Sludge Storage Tanks

These tanks are used t o accumulate and s t o r e sludge during t h e e n t i r e wastewater flow period s o t h a t the f i l t e r p r e s s can be operated mostly during the nonnal working day.

Design parameters

Storage capaci ty - 28 hrs.

S t i r r e r s f o r uniformity and s o l i d s suspension


Volume of flow i n t h i s W.W.T.P. (mgd) - - - - - - - 0.8

0 - 3 2 a 7

Volume of flow i n Winchester W.W.T.P. (nigd) - - - - Factor for flow-increase (x) - - - - - - - - - - - - Suspended s o l i d s a n a l y s i s , combined wastewater,

Suspended s o l i d s a n a l y s i s , raw wastewater, Winchester

t h i s W.W.T.P. W L ) - - - - - - - - - - - - - - - 2,718

1 ,295 (&) - - - - - - - - -- - - - - - - - - - - - - - Factor f o r suspended sol ids- increase (x) - - - - - - 2.10

Volume of sludge generated a t Winchester,

Estimated sludge volume generated t h i s W .W .T 2.

see t a b l e 9 ( g p d ) - - - - - - - - - - - - - - - - 18,000

18,000 x 2.7 x 2.1 (gpd)- - - - - - - - - - - - - 102,060

4

Estimated sludge volume - 28 h r s ( g a l ) - - - - - - - 120,000

Number of tanks needed - - - - - - - - - - - - - - - Construct ion - reinforced concrete, rec tangular with s t i r rers .

109

Sludge Compaction

Compaction i n t h i s exe rc i se calls f o r the use of a f i l t e r p ress , thus r equ i r ing a s i c c i a 1 charging pulilp, and a hea t exchanger t o improve t h e rate of f i l t r a t i o n .

Sludge compaction pumps

Design parameters

Sand P ipe r , air ac tuated , o r equivalent

Maximum de l ive ry pressure ( p s i ) - - - - - - - - - 100 Siz ing and s p e c i f i c a t i o n s

Tota l volume of sludge (gal/day)- - - - - - - - - 102,600 Sludge compaction opera t ing day (h r ) - - - - - - Average rate of sludge flow t o f i l t e r p ress (gpm)

16

12

142.5

Sludge pump operat ing time (hrs) - - - - - - - -

Peak rate of sludge flow t o f i l t e r p ress (start of batch) (gpm) 300

Pump capaci ty required (gpni) - - - - - - - - - - 300

Cost es t imate

Manufacturer - Warren Rupp Pump Co, ,

i4cdel no. - SA3A

N a n s f i e l d , Ohio

Number required. @ 300 gpm - - - - - - - - - - - - 2

$1,400 $2,800

Estimated c o s t , each - - - - - - - - - - - - - - Tota l c o s t - - - - - - - - - - - - - - - - - - -

110

F i l t e r press

According t o information ava i l ab le t h e p l a t e and frame f i l t e r press is capable of dewatering sludge t o a g r e a t e r degree than any o the r equipment designed f o r t h a t purpose.

Design parameters

Piaxiniwn dewatering is economically e s s e n t i a l .

Solids content of press cake (%) - .. - - - - - - - - - - 35 Siz ing and s p e c i f i c a t i o n s

To ta l volume OP sludge, Winchester (gpd) - - - - - - - - 18,000

Tota l volume of s ludge, t h i s unit (gpd) - - - - - - - - 102 600

2, [boo 13,680

Factor of s i z e illcrease (x) - - - - - - - - - - - - - - 5.7 2 Tota l f i l t e r area, Winchester f i l t e r press ( f t ) - - -

F i l t e r area needed, t h i s u n i t ( f t ) - - - - - - - - - 2

Cost estimate

Cost of Winchester f i l t e r p ress , i n s t a l l e d 1976 - - - Cost of Winchester f i l t e r press, j n s t a l l e d 1978 - - - Zstimated c o s t of unit 5.7 times l a r g e r - - - - -

$55, coo

$365 ,650 $64,150

- - Heat exchanger

Design parameters

S t a i n l e s s s tee l cons t ruct ion (316) Temperature increase - 2 5 O C t o 65'C


88

50 300

6

2 Contact area of blinchester u n i t ( f t ) - - - - - - - - Peak rate of sludge flow Winchester u n i t (gpm)- - - - Peak rate of sludge flow t h i s un i t (gpm)- - - - - - - Factor of increase i n contac t area needed - - - - - - Estimated contac t m a , t h i s u n i t ( f tL) - - - - - - - 528

$4 # 000

$4,645 $28,000

Cost estimate Cost of Winchester u n i t 1976 - - - - - - - - - - - - Cost of Winchester u n i t 1978 - - - - - - - - - - - - C o s t of u n i t 6 times larger - - - - - - - - - - - -

111

A i r Compressor

Since the sludge compaction pulp i o air actuated it is importazt to have an adequate and r e l i a b l e a i r source r e a d i l y ava i l ab le . t h a t the tannery cornpressed a i r would be adequate, but i n -the absence of information, compressed air generat ion is being incl*uded.

It is poss ib le

Ilesign parameters

A i r p ressure required ( p s i ) - - - - - - - - - - - A i r volume required , each pump (cfm)- - - - - - -

max 100

i n a x 125 Siz ing and s p e c i f i c a t i o n s

Number of compaction pumps spec i f i ed - - - - - - Air requirement VS. Winchester W,W.T,P. (x)- - - Nariufacturer - Kellog American

k d e l no - A 462-TVI Oakmont, Pa.

2

2

25 83

$3,000

3,500 $5,000

Motor HP - - - - - - - - - - - - - - - - - - - - Capacity :g 100 p s i (cfm) - - - - - - - - - - - -

Cost of Winchester compressor 1976 - - - - - - - Cost of Winchester compressor 1978 - - - - - - - Cost of compressor wi th 2x capacity (est>- - - -

Cost estimate

Carrousel Oxidation Ditch

Design parameters

The volurne of the oxidat ion d i t c h and the number a d s i z e cf a e r a t o r s is determined by the amount of oxygen dernanding material i n the feedwater en te r ing the d i t c h . BOD and TKM each use oJuygen. Both are s u b s t a n t i a l l y reduced i n the p r b a r y treatment phase, s i d u a l material after primary treatment determines the load on the secondary,

BOD by 60$, and TLN by bo$. The re-

Design MLSS (mg/l) - - - - - - - - - - - - - - - 7,500 Design F/N r a t i o - (BOD/MLSS) - - - - - - - - - .06

Fixed design average swd i n ca r rouse l ( f t )- - - - 13.4 13 Fixed design s i n g l e channel width ( f t ) - - - - -

Oxygen required t o s a t i s f y BOD and 'IXN i n the ca r rouse l

1.5. x 3OU + 4.6 x TKN Oxygen r a t i n g p e r a e r a t o r 02/hp/hr - - - - - - - - 3 -5

1 1 2

Sizinc; and. s p e c i f i c a t i o n s

303 present i n conibiried flow rail wastewater Grg/l) - - - 1,630

652 126

76

4,353 507

Residual l3OU a f t e r 60/; removal i n pr imaq !m&) - - - - liw presext in combined flow rag wastewater (ngb) - - - ~ e s i d u a l TiIi after 40;: removal i n primary (rrg/i) - - - - Average d a i l y t o t a l flow (mgd) - - - - - - - - - - - - E03 en t e r ing the secondary (lblday) - - - - - - - - - TKN en t e r ing the secondary (lb/day) - - - - - - - - -

I , r-7

0 *8

Oxygen furnished yer a e r a t o r (02/hp/hr) - - - - - - - 3 0.5

Calculat ion of volume of car rouse l

ROD 5 0.06 == LIES (lb) 4353 0.06 = 72,550

72,550 lb 5% 7,500 mg/l = 1.15 E! g a l

l . l 5 l c G = 152,520 f t 3

3 Volume (ft ) - - - - - - - .. - - - - - - - - - - - - - AverGre depth (ft) - - - - - - - - - - - - - - - - - Surface =ea ( f t 2 ) - - - - - - - - - - - - - - - - -

Calculat ion of t o t a l channel length

Calculat ion of sur face area of car rouse l r.

152 J 520 13 05

11 , 300

S u r f a c e a r e a ( f t ) - - - - - - - - - - - - - - - - - - 2 11,300

Design channel width ( f t ) - - - - - - - - - - - - - - 13 Tota l channel length ( f t ) - - - - - - - - - - - - - - 870

Selec t ion of number of channels

870 f t , t o t a l channel l eng th required, i nd i ca t e s using a configura- t i o n of t h e channel c i r c u i t s , six s i n g l e channels, each 135 f t . long p lus 80 f t of c ros s channel automatical ly included. rarigement‘ calls f o r three ae ra to r s .

Calculat ion of a e r a t o r horsepower required

Oxygen required = 1.5 x BOD + 4.6 x TKN

O2 = 1.5 x 4353 + 4.6 x 507

HI? = 8,862

Three a e r a t o r s w i l l be used, see channel s e l e c t i o n above. Each a e r a t o r (m) - - - -.. - - - - - - - - - -

This ax-

= 8,862 lb/day O 2 (3.5 x 24) = 105.5

- - 40

113

Cost estiniate

Voluxe or” i l inchester ca r rouse l (gal) - - - - - - - - - - - 380,000 3 Volume of : / inchester ca r rouse l ( f t ) - - - - - - - - - - -

3 volume of this c a r o u s e l ( f t ) - - - - - - - - - - - - - - Coniparative s i z e of t h i s carrousel t o Winchester

Cost of Uinchester ca r rouse l u n i t 1976 - - - - - - - - - - Cost of Uinchester ca r rouse l uriit 1978 (8,;:yeear) - - - - - Astimated cos t of t h i s ca r rouse l u n i t ( 3 . 4 ~ ) - - - - - - - Carrousel l i c ense f e e ($.lo/gal) - - - - - - - - - - - - Total co s t , carrousel. unit - - - - - - - - - - - - - - - -

camoilsel (x ) - - - - - - - - - - - - - - - - I - - - -

TIL:

Secondary C l a r i f i e r

Although the p r h a r y s e c t i o n produces a c l e a r e f f l u e n t passing i n t o the secondary, b io log ica l a c t i v i t y i n the secondary generates a high l e v e l of suspended s o l i d s which have t o be renioved. dens i ty and therePore somewhat d i f f i c c l t t o separate

They a r e r e l a t i v e l y l i g h t i n

Design parameter6

Surface area at ye& flow (gal/f t2/day) - - - - - - - - - 300 Peak flotr =- 2x riorrnal aver;ltl;e flow,

S iz ing aid s p e c i f i c a t i o n s

Tota l average wastewater flow (gpd) - - - - - - - - - - - - 8G0,000

P e A flow ( g ~ ) - - - - - - - - - - - - - - - - - - - - -1,6c0,000

5,333 82

82

8

Peak flow 4 309 ( f t , 2\ - - - - I - - - - - - - - - - - - 2 Dianeter of 5,333 f t c i r c l e ( f t ) - - - - - - - - - - - - -

Diameter of f i n a l clarif ier ( f t ) - - - - - - - - - - - - - Depth of f i n a l c l a r i f i e r ( s w d ) ( f t ) - - - - - - - - - - - - Kanufacturer: Clow Carp.

Lodel: Veollow . P e r i f e r a l feed cen te r sludge draw, cen te r

Florence, Ky

e f f l u e n t o u t l e t

Cost estiniate

13 9 295 3 Volme of Winchester f i n a l c l a r i f i e r (f-t ) - - - - - - - - Volwiie of t h i s f i n a l c l a r i f i e r ( f t ) - - - - - - - - - - - 3 42,664

114

Cost of i,linchester unit 19'?6 - - - - - - - - - - - - - $33,590 Cost of kiinchestcr urAt 1978 - - - - - - - - .. - - - - $37,650 Xstimated cost of tiiis c l a r i f i e r ( 3 . 2 ~ ) - - - - - - - $120,000

Sludge Return Pimps

Chemical Tanks, Piping, Power and Wiring

The foregoing items and c o s t s a s ca lcula ted , and smnar ized i n t a b l e 16, are, i n par?,, f o r equipment i n place, including excavation where required. A major por t ion of the cos t of cons t ruct ion of any treatment p l a n t Is f o r small tanks, pmps m d piping, poiqer and wiring. i 'relirninary es t imates for these i t e m , i n the absence of engineering drawinds, nus t be w l c u l a t e d from e x i s t i n g data. Winchester t reatment p l a n t , t o t a l cos t , and ca tegor ica l c o s t s for tanks , pumps, pi2ing aid e l e c t r i c a l . Taken as a group tinesc t o t a l $122,jOO out of a t o t a l of $611,900, exclusive oP housing and labora tory ,or %Q:. This percent of t he t o t a l est imated c o s t of equipment f o r t h i s exe rc i se , a,s itemized i n t a b l e 16, amounts t o $380,700. iIowever, some items o€ pmips a r e included i n t a b l e 16, q g r e g a t i n g t o $25,350, and thus must be deducted from the t o t a l , So doing leaves an estimated balance ar?ount, t o cover chemical tar is , piping, power and wiring, of $355,300

Appefidix B lists c o s t s f o r many of the major items i n the

Housing

The dosing s o l u t i o n tanks, dosing pumps, f l o t a t i o n bas in and sludge compaction equipment m u s t be protec ted froin weather if located i n o t h e r than a t r o p i c a l cl imate. Considering .the s i z e and poss ib le arrangement of equipment it is estimated t h a t a bui ld ing about 200 f t x 100 f t would be requi red ,

115

Spec i f i ca t ion

A l l s tee l , insu la ted , 13utlcr bui ld ing or equivalent

Forced v e n t i l a t i o n at roof peaks.

Approximate s i z e 100 ft x 200 f t .

Concrete s l a b f l o o r wi th d r a i n s .

Cost es t imrtte

S ize of Winchester bui ld ing - h n g t h (ft) - - - - - - - - - - - - - - I - .. - 104

40 Floor area (Pt") - - - - - - - - - - - - - - - - - 4,160

Size of bui ld ing needed, t h i s exe rc i se Length (ft) - - - - - - - - - - - - - - - - - - - Width (ft) - - - - - - - - I - - - - - - - e -

200

100

Floor area ( f t ) - - - - - - - - - - - - - - - - - 20,000

Cost of Yinchester build-ing 1976 - - - - - - - - - - $87,500

Cost of blinchester bui ld ing 1978 (es t ) - - - - - - - $102,000

Estimated c o s t of housing, t h i s p r o j e c t - - - - - - $400,000

- 2

This estimate has been reduced from $gOO,OOO i n deference t o s i z e , r e a l i z i n g t h a t the re would be sonie economy i n s c a l e .

116

Item c o s t

Beamhouse flow holding, equal iz ing , and c l a r i f y i n g tank $275 ? 000 Tanhouse flow holding, equal iz ing , and c l a r i f y i n g t m k 115,000

Constant flow head box 750

Cot1stant flow supply pumps 3,000 Tanhouse wastewater flow punlps 2,000

pH serisirig for ac id wazs.Le fLor-r con t ro l 1 t 700 Dosing pmip - alum 250

Dispersed air genera tor 4,500 Coagulation c e l l 10,50G

Dosing p u q - po lye lec t ro ly te 300 Subble c l a s s i f i e r 750 lectroC1ea.r s o l i d s f l o t a t i o n bas in 80,820

12,250 Current r e c t i f i e r

SIiiriiirlgs pump 1,500

Sludge s t o r q e tanks 150,000

Air compressor 5,000

F i l t e r press 365 9 650 28,000

Secondary c lar i f ier 120 * 000

Sludge re turn pwrips 5,000

Sol ids S1UX"y $JUlTiYS 10,500

Sludge coilpaction pmp 2,800

Heat exchanger

Carrousel oxidat ion d i t c h , conplete 708,085

Tota l f o r above

Chemical tanks,

Housing

Tota l

Cor1tint;ericie 2 - To~ts!. es-ti1,,a tecl

piping, power and wiring

1 C k , ;

c o s t of' p ro jec t

$1,903 , 355 355 , 300 400,000

$2,658,700 265,800

1 1 7

Estimated Cost of Operation

Examination and s tudy of t a b l e 15 r evea l s t h a t a c a t t l e h i d e , chrome, pulp h a i r , tannery could be expected t o emit e f f l u e n t i n s l i g h t l y less volume per pound of r a w hide o r pelt than a shea r l i ng tannery, 6.1 ga l / lb hide vs . 7.2. I n terms of BOD and suspended s o l i d s , t he ca t t l eh ide tannery wastewater contains about double t h e amount of the shea r l i ng tannery i n each ins tance . Since most of the cos t of operation is i n removal and depos i t ion of suspended s o l i d s , and i n e l ec t r i c power f o r a e r a t i on t o support b io log i ca l a c t i v i t y for BOD reduct ion, it fol lows t h a t the cos t of operation of a treatment f a c i l i t y f o r a c a t t l e h i d e , chrome, pulp-hair tannery would be about double t h a t of a shea r l i ng tannery. Sect ion 8 r evea l s a cos t of $l . .7yper thousand ga l lons of wastewater t r ea t ed . Assuming some economy of scale t he cos t of operation f o r t h i s model would be expected t o be on the order of $3.00 per one thousand ga l lons t r e a t e d .

118

Comparison of parameters i n Table 15 for the category 3 tannery - veg t an , c a t t l e h i d e , h a i r save - with category 7 , s'nearlings, r evea l s a high d.e- C r e e of s i m i l a r i t y . BCi.9, Suspzrdcd Solids, and volune of e f€ luen t , t h e nos t s i g n i f i c a n t p a r m e t e r s , axe all very c lose t o being the same. as i n categord' I, alkal ir ie betinhouse wastes and ac id tanhouse wastes are involved . Therefore the s m e approach t o tmatinent , par t j -cular ly as it per- t a i n s t o the prlrnary sec t ion , would be used as f o r the category 1 tamiery. See schematic di,ag", Figure 43. formation a r c used in t h i s exe rc i se as used f o r the category 1 development preceding .

I n category 3,

Also the same sources f o r background in-

%sic Design Parameters - Vegetable Tan, Save Hair \I .IJ .TOP . 0 .3 0 215

Tota l flow (mgd) - - - - - - - - - - - - - - - - - - - - deamiiouse flow ( r n g ~ ) - - - - - - - - - - - - - - - - - - - Tmhouse f low (mgd) - - - - - - - - - - - - - - - - - - - P o l l u t a n t loadings - see Table 15 Treatmefit p l a n t operat ing day (h r ) - - - - - - - - - .- - Zqualized tanhouse f l o x (gpm) - - - - - - - - - - - - - Tota l equalized treatment p l a n t operat ing f l c w (gp1n)- -

0,085

20

Jqual ized beamhouse flow (gpm) --- - - - - - - - - - - - 179 71 250

Design and Cost Zst imation of Components

C o m e Screening

Raw Wastewater Purips

Not inclucied. See coinments page 99

Holding and. Equalizing Tanks

See genera l comments page 99. The s i z i n g of the two tanks i n t h i s case are ca lcu la ted on the b a s i s o f volume needed t o accomcdate 10 hours of flow from each source, a l k a l i n e and. acid .

119

a a W J 0 0

I- o W A

a

.A W cn 3 0

a o

a a

0 I I W

0

I - X z o u m

z a L O = o w o x

- b U a

W v )

%! I

\

120

Eexihousc f lox holding, equa l iz ing , anil c l a r i f y i n g tank

This tank is of concrete rec taagular . See genera l comments page 10 0,

Design p ~ m c t c r s

Detention time (hr) - - - - - - - - - - - - - - - - Beamhous? flow (mgd) - - - - - - - - - - - - - - - -

9 0 Siz ing of t Volume - 7% x 215,000 (gal) - - - - - - - - - - - - Constant - ga1.jf.t 3 - - - - - - - - - - - - - - -

10 0.215

89 , 600 7.5

11,944-

65 13

14

95 $110

Tanhouse f l o ~ holding, equal iz ing , and c l a r i f y i n g tank

This tank is a l s o constructed of concrete , rec tangular , an1

552 000

of the same t o t a l concept as t h e beanhouse flow tank except t h a t it is smal le r . comments pagc 100

See

0.005

10

35 , 4.20

4,722 I4 13 26

7 *5

1 2 1

Cons-Last Plow Squipmen-t

See general conmerits page 101-.

Constant flow head box See s e c t i o n 3

Design parameter 32

3

Horizontal cross- sect ion (ft"/gal/min) - - - - - - - -

Consta1t flotr su.pply puTil;s

See general corments p q e 102

1 2 2

Dosing Pump - A l w n

See general comments page . l O 3 . I)esig-n paxmieter

1,000 mg/l -to be added t o combined beamhouse- tanhouse flow A l u m solution 45:: s o l i d s 8 s p g r 1.330, 11.1 lb/gal.

1 2 3

Siz ing and pump speciPica t ion

R u a l i z e d beamhouse flow (gpm) - - - - - - - - - - N u a l i z e d tanhouse flow (gpm) - .. - - - - - - - -- T o t a l equalized flow (bpi~~) - - - - - - - - - - - - Weight of flow ( lb /gal ) - - - - - - - - - - - - - J e i e h t of f l o x (lb/min) - - - - - - - - - - - - - Weight of alum 4 1,000 mg/l (lb/min) - - - - - - - J e i e h t of alum s o l u t i o n P 43,; s o l i d s (lb/inin) - - Volume of alum s o l u t i o n 9 11,l lb /gal (gpm) - - - Pump capaci ty required (gpm) - - - - - - - - - - Manufacturer - Liqu i f lo r7idipnent Go, S e r i e s 3b 3 gpm 0.5 i n 316 SS blotor 1.p - - I - - - - - - - - - - - - - - - - Variable speed - max rpm - - - - - - - - - - - - -

Cost estimate

Pump and motor (est) - - - - - - - - - - - - - - - Dispersed A i r Generator

See Figure 5 See genera l comments page 104.

Design parameter 3 F t of air/100 giL of flow - - - - - - - - - - - -

Siz ing and s p x i f i c a t i o n s

lhnufsc tuyer - Lighting Mixer Corp , I4cdel No, - 4 - L8C - 200 j i n 316 S S i { o t o r W - - - - - - - - - - - - - - - I - - - -

Cost estimate Generator crith motor, complete - - - - - - - - - -

Coagulation C e l l

0.75 ijc 1,725

$250

2

$3,500

See F i g w e 6 See genera l comments pagelO5.

Design p a r m e t e r

Zffective residence time 2 min-ates

1 2 4

Sizing and spec i f ica t ions

Total equalized flow r a k e (gpm) - - - - - - - - - - Cell volume requi red f o r 2 min flow (ga l ) - - - - - Cel l volume required f o r 2 min floli ( f t ) - - - - - Uiameter of top s ec t i an ( f t ) - - - - - - - - - - - Depth of top sect ion ( f t ) - - - - - - - - - - - - - Diameter of bottom sec t ion ( f t ) - - - - - - - - - - Depth of bottom sec t ion (ft) - - - - - - - - - - - B4anufacturer - Local sheet metal shop

3

Cost est imate

Same as l!inchester 1976 updated t o 1978 - - - - - - Dosing Pump - Polyelect rolyte

See general comients page 105.

Design parameter

12 mg/l t o be added t o combined flow Polyelectrolyte so lu t ion s t reng th - 0.2$

Sizing and spec i f ica t ions

Total equalized flow rate (gpm) - - - - - - - - - - IJeight of flop; (lb/gal) - - - - - - - - - - - - - - Weight of flow (lb/min) - - - - - - - - - - - - - - Weight of polyelect rolyte needed Q 12mg/l (1b)- - - Solution s t reng th ($) - - - - - - - - - - - - - - - Weight of so lu t ion needed @ 12mg/l ( l b ) - - - - - - \?eight of so lu t ion (lb/g&l) - - - - - - - - - - - - Volwne of solu.tion needed ( g p n i ) - - - - - - - - - - Pump capacity needed (gpn) - - - - - - - - - - - - Fianufacturer - Liqui€ lo Xquipment Co . Ser ies 36 - 5 gpn 0.75 i n 316 SS Motor Hp - - - - - - - - - - - - - - - - - - - - - Variable speed 1,725 r p m m a

Cost es tiniate

pump and motor (est) - - - - - - - - - - - - - - -

250

500

67 7 *5 2 -5 7.3 1.8

$10,500

25.0

2,100

8.4

,024

0.2

12

8.5

1 .'+ 1.4

$300

125

Subble Classifier

See 2’igure 7

See general comments page 106.

Des igri pai-ai~c tc? r

Depth -: 1 ft/100 gym

Siz ing and s p e c i f i c a t i o n s

Tota l equalized. flow r a t e (gpni) - - - - - - - - - - - 2 2 Surface a r e a 3 3 f t /IOO gpin ( f t ) - - - - - - - - -

Depth (ft) - - - - - 250

7 . 5 2 .5 - - - - - - - - - - - - - - -

I”,anufactuer - Local sheet metal shop

Cost estimate Same as 1976 ulrxlated 3 8$/:/yr (est) - - - - . - - - - - 8 500

LectroClear So l ids F lo ta t ion B a s i n

For desc r ip t ion see s e c t i o n 3 .

The design operat ing f l o i ~ i n t h i s exercise is 250 gpili. The opera-Ling flow through the Iiiiichester treatment p l a n t is 300 gpm, very nearly t he same. Therefore the sau,ie design arxl dirnerisions would s a t i s f y the need i n t h i s case.

Cost estiriia-be

Cost of Uirichester u n i t 1976 - - - - - - - - - - - - Cost of Winchest.er u n i t 1978 - - - - - - - - - - - - Kunber of e l e c t r d e s - - - - - - - - = - - - - - - - Cost of e l e c t , r d e s , each - - - - - - - - - - - - - - T o t a l c o s t of e l ec t rodes - - - - - - - - - - - - - - Total c o s t of f l o t a t i o n bas in , ins -balled - - - - - -

$31,200 36,400

74 $35

7,030 $43,430

Current R e c t i f i e r

Direct cu r ren t is required for microbubble generatior, by e l e c t r o l y s i s i n the LectroC1ea.r f l o t a t i o n basin.

S iz ing and s p e c i f i c a t i o n

Same as i i n c h e s t e r , See s e c t i o n 3.

1 2 6

Sol ids Sliir.ry Fu ,ys

St.e ,onera1 coiriile.ii;s ?age 108. 3esiCn parameters

-!AlLbi&A cii{,,isl i - ~ ki i i . , t ~

Corros ion x-cs is tan t const ruct ion

Siz i : i t arid speci f ica t ior t

'i"0ia.i voiurne of 'ceanhouse flow ( ~ i g d ) - - - - - - - - - Suspended s o l i d s re.noval by sediilien ta t lor i ( e s t ) (mg/?)- Corlstarlt (lb/&) - - - - - - - - - I - - - - - - 'deight of bearrhouse flow (lb/day) - - - >/eight o f suspended s o l i d s removed (lb/day) - - - - - Ideight of s o l i d s s l u r r y e? l$ s o l i d s (lb/da,y) - - - - - Xeight of slurry (ib/@) - - - - - - - - - - - - - - Volume of beamhouse flow (gpd) - - - - - - - - - - - - Average pumpia, rate 3 20 hr . day (gpm) - - - - - - - Y g t d volune of tanhouse .?low (1n;d) - - - - - - - - - Suspended s o l i d s removed by sedimer,tation ( e s t ) (mgb)

- - - - - - -

Coils-t,ant ( l b / g p ~ ) - - - - - I I - .. - - - - - - - - - : J c ? i & t of tanhouse flow (lb/day) - - - - - - - - - - - 'deight of suspended s o l i d s removed (lb/day) - - - - - Sleight o f s o l i d s s l u r r y B 1;; s o l i d s (lb/da.y) - - - - - Weigrit of s l u r r y ( lb/gal) - - - - - - - - - - - - - - Volume of tanhouse f i m s o l i d s sluL*ry (g;pd) - - - - -

0.215

3 *5 500

1,027,500 9 14

9 1 , MO

8 0 . 5

10,750 3

0.0~5

8.5 bo0

722,500 289

28,900

3,400 8.5

1 2 7

Average pumping rate 3 20 h r . day (gpm) - - - - - - Number of purups required - 3 Interchangeable

Pump s e l e c t i o n - 'i'aughrl Chopper

Nanufacturer - Vaughn Co., I nc . liontessiio, h * r t ~ h .

lilodel 150 Notor 5 i 8 1,750 rpm

3

Cost estiiiiate

Pimps, each $3,500 - - - - - - - - - - - - - - - - $10,500

Sludge S t o r w e Tanks

These tanks are used t o a c c m u l a t e and s t o r e sl~idge dur ing the eritire d a i l y wastewater flow period so t h a t t h e f i l t e r press can be operated mostly dur ing the normal working day. Table 15 ir.dicatcs t h a t t h e t o t a l iiydraulic flow, and the incidence of suspended s o l i d s is nu more i n the veg-tal h a i r save c a t t l e h i d e tarmery than a t Winchester, the re fo re , the sane tank des ign and capaci ty can be used. See s e c t i o n 3 .

Cost est i n a t e

Two 12,000 ga l lon s t e e l tanks

$3,500 each - - - - - - - - - - - - - - - - - - $7,000

Sludge Coiripact ion

See general comments page 110.

Since t h e rrastewater i n t h i s exerc i se is expected t o generate t h e same ariourit of sludge as t h e Winchester tannery efflcLent, t h e same equipaent items and the sitme s i z e of each can be used.

Sludge compaction pumz

Spec i f i ca t ion

Kanufacturer - lilarren Rupp T m p Co. I*iansPield, Ohio

Nodel 210. - SA3A

Cost estimate

F i l t e r press

See general coinraents page 111.

1 2 8

The press now i n service at Uinchester should be adequate f o r t h i s use.

Specif icat ioris

€-;anufacturer - D . 3. Sperry Co.

ilodel KO. 48 E f i L

75 rec tangu la r , pyranid face p a t t e r n , 48 i n by 48 i n p l a t e s . Center feed , coruer vent .

E a s t Aurora, 111,

Cost e s t i n a t e

Cost of 'slinchester p ress 1976 - - - - - - - - - - - Cost of J inches te r p ress 1978 - - - - - - - - - - -

$55,000 $64,150

Heat exchanger

The u n i t now used f o r t h i s purpose at Winchester should be adequate. See sec t ion 3 .

14 a

$4,000

$4,665

A i r Cornpressor

See genera l cormients page 112.

Thc sxac s i z e compressor as t h a t i n use a t Winchester w i l l suffice.

Design parameters

Alr pressure required ( p s i ) - - - - - - - - - - - - max 100

125 A i r volume required (cfm) - - - - - - - - - - - - - max

i\Tumber of coriipaction purnys - A i r requirement VS. 'nlinchester - - - - - - - - - - -

Siz ing arld s p e c i f i c a t i o n s - - - - - - - - - - - - 1

sane

129

>!a-.luf acturer - KelZog American

r%xlei K O , A-k62-TVI

O&mont, Pa.

25 po to r €8' - - - - - - - - - - - - - I - .. - - - - - Capacity 9 100 p s i (cfc;) - - - - - - - - - - - - - - 8.3

Cost e s t i n l a te

Cost of Xinchcs%er compressor 1976 - - - - - - - - - $3,0L10

Cost of Wirxhester compressor 1978 - - - - - - - - - $3,500

Carrousel Oxidation Ditch

Due t c s i m i l a r i t y of' wastewater c h a r a c t e r i s t i c s a d i t c h of the same s i z e and d e t a i l e d s p e c i f i c a t i o n s should be adequate f o r t h i s use. See sec- t i o n 3.

Cost es t i a a t e

Cost of Winchester u n i t 1976, exclusive of punps, piping, vslvek, and e l e c t r i c a l - - - - - - - - - - - - - - - $2~1,200

COS+, of SESE, 1978'- - - - - - - - - - - - - - - - - $293,000

Seconhry Clarifier

See gerieral comlents page 114.

A s is true with o ther conponents of t h i s t reatment p l a n t the Ilin- Chester s i ze arid spec i f i ca t ions w i l l provide an adequate secondary c l a r i f i e r . See sec t ion 3.

Cost estiinate

Cos t of Winchester secondary clarif ier 1976 - - - - Cost of iu'inchester secondary c l a r i f i e r 1978 - - - -

$33 ,50G

$39,000

Sludge Return Pun~p

130

The sane s t e e l S u t l e r bui ld ing will provide the 1xmtectA.m needed for t h i s app l ica t ion . See scct iori 3.

Spec i f i ca t ion

ib,nufacturxr - i3ubl.er 2 u i l d ines , Inc . Dimensions - '$0 ft xitie x 104 ft long.

IJoncre t e f i o o r w i t h d r a i n s ,

Cost e s - L Ima,t e

Cost of i i n c h e s t e r B u t l e r building 1976 - - - - - - - - Sost of ;!inchester 3 u t l e r building 1978 - - - - - - - -

$37,500 $1102,000

See explamtion page115. defer t o table 17 instead of table 16 f o r i t c x i z s t i u n of q u i p i e r i t cmd total i sa t ion of cw.t.

131

I t e m i: 0s t

132

Estimated Cost of Operation

Reference t o t a b l e 15 r evea l s t h a t t he r e are no s u b s t a n t i a l d i f f e r - ences i n po l l u t i on load o r volume, per pound of raw hide or p e l t , between a c a t t l e h i d e , veg t a n , h a i r save, category 3 tannery and a category 7 shea r l i ng tannery, Therefore t he operat ing c o s t s presented i n terms of a number of parameters i n s ec t i on 8 are appl icab le t o t h i s model.

General Statement

It must be recognized t h a t t he attempted technology t r a n s f e r from a category 7 tannery t o one of category 1 and one of category 3, as descr ibed i n some d e t a i l i n t h i s s ec t i on is not based upon a c t u a l experience. Obviously t he r e has been no opportunity t o apply t he p r inc ip l e s used i n t he Winchester treatment system on any o ther tannery wastewater, The concept suggested f o r rece iv ing and combining two waste streams, a lka l i ne and a c i d , only seems t o have c r e d i b i l i t y based upon observations at t he South P a r i s f a c i l i t y . b io log i ca l a c t i v i t y i n t h e oxidation d i t c h with respect t o carbonaceous as w e l l as nitrogenous b a c t e r i a s t r a i n s it can only be speculated t h a t similar r e s u l t s would be forthcoming if s i m i l a r condi t ions would be es tab l i shed .

A s f o r

The f a c t o r of scale has not been taken i n t o account i n t he calcula- t i o n s f o r construct ion of most of t he high cos t items, p a r t i c u l a r l y i n t h e chrome c a t t l e h i d e model, hence more engineering refinement could r evea l lower c o s t s t he r e .

133

SECTION 10

REUSE OF TREATED WASTEWATER

A d e f i n i t e p o t e n t i a l would seem t o e x i s t f o r wastewater reuse a t the Winchester tannery, has s u b s t a n t i a l de f i c i enc i e s . During the win ter , the water temperature is well below the acceptable l e v e l f o r use, and during the summer, it can be too w a r m , times it is far from pure. more uniform i n some important aspects than t h e source from which it is drawn, and seemingly it could be used t o advantage at almost any poin t i n t h e process.

River water, the primarry source of p l a n t process water,

A t times of f looding contamination is considerable,and, indeed a t all Thus t h e t r e a t e d e f f l u e n t water is cons i s t en t ly

Recycled water does have some real l i m i t a t i o n s , however. The purpose of wash water is’ t o carry off contaminants and o ther unwanted components, and some of these , p a r t i c u l a r l y sodium chlor ide (salt), are non-compatible pollu- t a n t s . These pass through the t reatment p l an t and are present t o almost t h e same degree af ter t reatment as before. Consequently, i n order t o avoid compounding t h e ex is tence of these materials i n t h e process water, considerat ion of r e c i r c u l a t i o n has t o be performed i n the l i g h t of t h i s r e s t r a i n t ,

Pos i t ive ac t ion should be taken t o recover some of t h e energy used t o Wastewater taken after passing through the primary sec- heat process water.

t i o n of t he treatment p lan t could be expected t o be 40°F warmer i n win te r and 100F warmer i n summer than r i v e r water, a year-round average of Zj°F. This represents hea t t h a t would normilly be wasted bu t t h a t perhaps could be recovered simply by recyc l ing , On the o the r hand contaminants i n t h e form of BOD, ammonia, TKN, and traces of r e s i d u a l dyes tu f f s still e x i s t i n t h i s water.

During the secondary t reatment s t e p t h e continuous churning of mechanical ae ra t ion lowers t he water temperature through evaporat ive cooling, and dur ing the cold season direct hea t transfer t o t he atmosphere occurs. Accordingly it might seem more reasonable t o consider reus ing water which has passed through t h e primary s e c t i o n only when concerned with heat recovery. However, t h e unique design of t he car rouse l with r e spec t t o r e s i s t ance t o atmospheric in te r fe rence accomplishes heat r e t e n t i o n t o a l a r g e degree even i n winter , s o t h a t t he temperature d i f f e r e n t i a l between e f f l u e n t water from the secondary clarifier, and r i v e r water becomes 30°F i n win te r and 5OF i n summer, o r an average of l7.5OF. While t h i s is not as a t t r a c t i v e as the primary ef- f luen t average d i f f e r e n t i a l of Z5OF it is c e r t a i n l y appreciable and t i p s t h e scales i n favor of using t o t a l l y treated e f f l u e n t i n t he reuse concept versus t h e somewhat warmer bu t less pure primary t r e a t e d e f f l u e n t flow.

The primary ind iv idua l uses f o r water i n a shea r l i ng tannery include i n i t i a l pelt washing, soaking, make-up water f o r s a tu ra t ed br ine , hose-down

134

f o r clean-up, make-up water f o r p ick le l i q u o r s and c e r t a i n t a n l i q u o r s , and wash and make-up water used dur ing dyeing and fa t- l iquor ing procedures. t h a t a l l of these uses , with t h e exception of hose-down f o r clean-up, have t h e capaci ty f o r adversely a f f e c t i n g the q u a l i t y of t h e product, p o t e n t i a l dangers not i d e n t i f i e d by r a t i o n a l i z a t i o n must be determined through extensive t r ial before reuse is i n s t i t u t e d , Each usage as above w i l l be con- s idered individual ly as t o material and energy savings. Obviously t h e material savings w i l l be l imi ted t o sal t s ince t h e water t o be used is t h e product of a p u r i f i c a t i o n process designed t o remove o the r components which conceivably otherwise might be present i n recoverable amounts.

Note

Therefore any

RECOVERY AND USE FOR PELT WASHING

A large port ion of t h e water used i n t h i s tannery is used f o r washing pelts, A s received they con ta in much salt and animal s o i l . The water used is r i v e r water warmed as necessary, depending upon the time of year , t o about 85OF, thus consuming energy. In fact, a large p a r t of t h i s exercise is salt removal. Thus it becomes necessary t o consider the impact of adding salt t o the wastewater discharge system a t t h i s point from two d i r e c t i o n s r a t h e r than one i f wastewater is reused, t h a t i n and on the sk ins , as usual , and t h a t i n t h e recycled wastewater i f recycl ing should be prac t iced .

No salt is used a t t h i s point .

The following facts help t o examine t h i s s i t u a t i o n :

P e l t s processed pe r day - - - - - - - - - - - - - 3,600

1.5 5,400

Water used f o r pelt washing (gal/day) - - - - - - 150,000

8 345 1.005

8 387 Weight of l_SO,OOO g a l of recycled e f f l u e n t ( l b ) 1,258,050

I .2

15 , 097

S a l t i n and on p e l t s as received ( lb /pe l t ) - - - - S a l t en te r ing the system on pelts (lb/day)- - - - Weight of water @ s p . g r . 1.000 ( lb/gal)- - - - - Spec i f i c g rav i ty of e f f l u e n t - - - - - - - - - - Weight of e f f l u e n t @ sp . gr. 1.005 ( lb /gal ) - - - S a l t content of e f f l u e n t ($6) - - - - - - - - - - S a l t en te r ing the system i n recycled

e f f l u e n t (lb/day) - - - - - - - - - - - - - - - These figures c l e a r l y show t h a t on the o d e r of three times as much

salt would r e t u r n t o the p e l t washing operat ion as it is des i red t o remove, thus i n t e r f e r i n g g r e a t l y wi th the e f f i c i e n c y of t h i s process s t e p . Even i f e f f e c t i v e washing could be achieved by using e f f l u e n t f o r the f i r s t batch washes, and f r e s h water f o r the last batch washes, recycl ing of even ha l f as much salt would lead rap id ly t o s a t u r a t i o n d t h e wastewater system with sodium chlor ide .

135

Energy Savinq

As s t a t e d above, i n i t i a l p e l t washing does consume a considerable amount of energy i n t h e use of wash water at 100°F. the foregoing paragraph, the concept of r ecyc l ing water containing salt t o a process s t e p t h a t is primari ly concerned wi th sal t removal, prevents s e r i o u s considerat ion of any o the r aspect of reuse, including energy saving.

However, as discussed i n

RECOVERY AND USE FOR BRINE PREPARATION

Recycling of e f f l u e n t f o r use i n b r ine prepara t ion could r e s u l t i n measurable savings. The l i x a t o r system f o r b r ine pmpara t ion , as prac t iced a t Winchester, i n itself is a p u r i f i c a t i o n process s ince make-up water is passed through a large bed of rock sal t a s a means t o achieve s a t u r a t i o n . This mode of reuse of t r e a t e d wastewater seems t o hold t h e g r e a t e s t promise of success among those envisioned.

Material Saving

The fol lowing facts apply:

S a l t used i n b r ine prepara t ion (lb/day) - - - - - - 30,000

S a l t content of sa tu ra ted b r ine ( lb/gal)- - - - - - 2.65

Volume of b r ine used (gal/day) - - - - - - - - - - 11,400

Since 11,400 gal of sa tu ra ted b r ine is consumed each day, on the average, t h i s is the l i m i t of recycle volume f o r e f f l u e n t t o be used f o r t h i s purpose .

Weight of e f f l u e n t 3 sp. gr . 1,005 ( lb /gal ) - - - - 8 0387 Weight of 11,400 gal e f f l u e n t ( l b ) - - - - - - - -95,608

S a l t content of e f f l u e n t (%) - - - - - - - - - - - S a l t content of 11,400 g a l e f f l u e n t ( l b ) - - - - - 1,147

1.2

Cost of rock sal t as received ( l b ) - - - - - - - - $ ,018

Value of salt recovered / day - - - - - - - - - - -$2O 065 Value of salt recovered / year (250 days) - - - - -$5,160

Energy Saving

Volume of wastewater poss ib ly recycled f o r br ine

See c a l c u l a t i o n f o r energy saving page 138 - - - - Yearly saving, heat recovery i n b r ine prepara t ion -

prepara t ion (gal/day) - - - - - - - - - - - -11,400

$990

136

RECOVERY AND REUSE FOR HOSEDOWNS AND CLEAN-UP 9

No material o r energy savings are envisioned f o r t h i s reuse per se. Temperature or salt content are no t important. Pumping c o s t s would be no less than f o r f r e s h water. On the o the r hand, consider ing the wastewater volume as an e n t i t y , it is cooled, p a r t i c u l a r l y i n win ter , through the addi t ion of cold r i v e r water t o it as a r e s u l t of using such water for hose-downs and clean-up. Therefore, reuse of w a s t e w a t e r f o r t h i s purpose could r e s u l t i n indirect energy conservation.

Energy Saving

Calculat ions are made as follows:

Volume of water used f o r hose-down and

See ca l cu l a t ion f o r energy saving page138

clean-up (gal/day) - - - - - - - - - - - - - - - - 15,000

Yearly saving, t h i s use - - - - - - - - - - - - - $1,300

RECOVERY AND REUSE FQR PICKLE LIQUOR MAKE-UP

Material and energy savings are poss ib le i n t h i s category. Reused ef-

Eff luent conta ins 1.2% salt, and is 17.j°F f l u e n t would ca r ry salt and hea t energy i n t o t h e p ick le l i q u o r s which would not have t o be provided otherwise. w a r m e r , on t h e average, than f r e s h water. A s stated before, un t r ied q u a l i t y considerat ions are paramount, and t h i s use could only occur after extensive t r ial and experience.

Material Savings

The volume of water needed f o r p ick le l i q u o r make-up determines t h e degree of economy i n e f f l u e n t recovery f o r t h i s purpose. automatical ly reduce the amount of s a tu ra t ed br ine needed t o reach t h e process spec i f i ca t ion f o r salometer.

The salt would

The following facts apply:

Volume of new p ick le l i q u o r (gal/day) - - - - - 12,000

1.2

Weight of e f f l u e n t ( lb /ga l ) - - - - - - - - - - 8 387 S a l t content of e f f l u e n t ($0) - - - - - - - - -

S a l t content of 12,000 g a l e f f l u e n t (1b)- - - - 1,208 Cost of rock salt as received (1b)- - - - - - - $.018

Value of sal t recovered / day- - - - - - - - - $21.74

Value of sal t recovered / year - - - - - - - - $5,435

13 7

Energy Saving

Volume of wastewater recycled f o r p ick le l i quo r ,

See c a l c u l a t i o n f o r energy saving below.

Yeaxly saving, t h i s use - - - - - - - - - - - - - -

make-up (&/day) - - - - - - - - - - - - - - 12,000

$1,042

RECOVERY AND RINSE FOR TAN LIQUOR MAKE-UP

This reuse is much the same as f o r p ick le l i q u o r make-up. A common d i s t r i b u t i o n system would serve both uses. a l l y reduce the amount of sa tu ra ted b r ine needed t o reach the

Again, the salt would automatic- required t o t a l

salometer l e v e l .

Material Savings

Volume of new t an l i q u o r (gal/day) - - = - - - - - S a l t content of e f f l u e n t (%) - - - - - - - - - - - Weight of e f f l u e n t ( lb/gal)- - - - - - - - - - - - S a l t content of 20,000 g a l e f f l u e n t ( l b ) - - - - - Cost of rock salt as received ( l b ) - - - - - - - - Value of sal t recovered / day - - - - - - - - - - Value of sal t recovered / year - - - - - - - - - -

Energy Saving

Volume of wastewater recycled f o r chrome

See c a l c u l a t i o n f o r energy saving below.

Yearly saving, t h i s use - - - - - - - - - - - - -

l i q u o r make-up (gal/day) - - - - - - - - - -

RECOVERY AND REUSE - TOTALIZED ENERGY SAVINGS

P o t e n t i a l volume f o r s a t u r a t e d br ine preparat ion

P o t e n t i a l volume f o r hose-down and clean-up - - - P o t e n t i a l volume f o r p ick le l i q u o r clean-up

P o t e n t i a l volume f o r t an l i q u o r make-up (gal/day)

To ta l p o t e n t i a l volume e f f l u e n t reuse (gal/day) - Weight of e f f l u e n t ( lb /ga l ) - - - - - - - - - - -

(gd /day) - - - - - - - - - - - - - - - - -

(gal/day) - - - - - - - - - - - - - - - - -

20,000

1.2

8 387 2 , 013

$ .018

$36 23

$9 9 058

20,000

$1,738

11,400

15, ooo

12,000

20,000

58,400

8 387

138

Weight of recycled volume (lb/day)- - - - - - - - - 489,800

Average temperature i n excess of r i v e r water ( O F ) - 17.5

Fuel value of f u e l o i l (BTU/gal)- - - - - - - - - BTU recoverable / day - - - - - - - - - - - - - - 6 , 571 , 514

148,000

58 $0 -35

$5,075

i@quivalent ga l lons of o i l recoverable / day - - - C o s t of o i l / ga l - - - - - - - - - - - - - - Value of recovered heat / day - - - - - - - - - - Value of recovered heat / year - - - - - - - - -

$20 . 30

1 3 9

TABLE 18. RECAP OF SAVINGS POSSIBLE THROUGH R U X V d R Y AND REUSE

h a t e r i a l Energy Use $ / Year $/year

L ( ' Brine prepara t ion 5 , 160 3 JC

iiosa-down and Clem-up - 1,300

Pickle l i q u o r make-up 5,435 1,0142

1,738 5,070

Tan l i q u o r make-up To ta l

Grand Tota l $24,723

The combined saving is s u b s t a n t i a l . It is probably riot f a c t u a l t o ex- pect t h a t a l l of the hea t energy would be recovered, but s ince t h i s r ep resen t s by far the lesser por t ion of the t o t a l savings, the hea t l o s s during transmis- s ion would not s e r i o u s l y impact the t o t a l .

I n order t o determine the v i a b i l i t y of a proposed recycle system from the po in t of view of c o s t of operat ion and c o s t of cons t ruct ion versus savings t o be r e a l i z e d , it is first necessary t o make a preliminary design of an ef- f l u e n t r e t u r n system.

Figure 44 is a schematic drawing of the tannery, the treatment p l a n t , and a proposed e f f l u e n t r e t u m system, more o r less t o scale.

ESTIMATZD COSTS FOR EFFLUENT REUSE

Consideration of 'Operating Costs

Figure 44 schematical ly shows f r e s h r i v e r water en te r ing the tannery f o r process use , The water is used almost e n t i r e l y on the first, o r ground f l o o r , and is d i s t r i b u t e d i n p a r t t o the same areas and use po in t s as con- s idered f o r reuse of t r e a t e d wastewater. This water is pumped from the l e v e l of the r i v e r t o the po in t of use through a v e r t i c a l r ise of about twenty feet . Pur i f i ed e f f l u e n t water would be pumped from a point about t e n feet above the l e v e l of the r i v e r t o exact ly the same l e v e l of use. aga ins t which each of the pumps wauld be working is v i r t u a l l y the same i n each case. The only o the r d i f f e rence between the two would be s e v e r a l hundred f e e t of a d d i t i o n a l pumping d i s t ance f o r t h e re turned e f f l u e n t , i ncur r ing some addi- t i o n a l dynamic head due t o pipe f r i c t i o n . Again t h i s is i n s i g n i f i c a n t , assuming proper design and pipe s i z i n g . It is a l s o the case t h a t the two d i f fe rences are counterbalancing.

Thus the s t a t i c head

140

i Ly

t 2

a L Y a c a Y Y Y 1

C Y r . Y 4 *

\; Y z

I c

Lo

3 w w z 0.

a

ad ala, L

L s ho

141

The conclusion becomes, the re fo re , t h a t punping c o s t s w i l l be the same whether f r e s h water o r t r e a t e d wastewater is used where app l i cab le ,

Cons ide rd t ion of Construction Costs

Figure 44. shows t h a t a r e t u r n system f o r t r e a t e d e f f l u e n t would c o n s i s t of a pump withdrawing t r e a t e d water from t h e o u t f a l l fropi the f i n a l c l a r i f i e r , and discharging i n t o an underground (belDw f r o s t l e v e l ) r e t u r n l i n e t o the tannery bui ld ings , and thence t o the po in t s of use. A l l piping and valves would be PVC. duction f i t t i n g s and smaller s i z e pipe, valves, f i t t i n g s , e t c . at; each point of use.

The main would be of f a i r l y l a r g e s i z e a l l the way, wi th re-

Following are design parameters and c o s t est imates:

Pumps

Estimated volume t o be reused (gal/day) - - - - - - - - - - 58,400

Time frame f o r m u s e - minimum (min/day) - - - - - - - - - 480

Average volume t o be reused (gal/min) - - - - - - - - - - - Estimated peak volume (gal/min) - - - - - - - - - - - - - -

122

130

5" suc t ion , 4" discharge s t a n d a d c e n t r i f u g a l , i ron body, motor direct connected (HP) - - - - - - - 30

$3,000 Estimated c o s t of pump arid motor, inplace - - - - - - - - -

Weather p ro tec t ion (pump house)

Construction - Prefabr ica ted insu la ted aluminum

Size - 8 f t by 8 f t o r s tandard . Concrete f l o o r

Pipe main t o tannery bui ld ing

Pwnp suc t ion l i n e

50 f t . 5 i n PVC - $315/C f t . - - - - - - - - - - - - - - - $158

Foot valve and f i t t i n g s - - - - - - - - - - - - - - - - - 75

142

Valving assemblies a t each p a i r of paddle p i t s .

One 4 i n t o 2 i n reducing tee - - - - - - - - - - - - - - - $10.40

One 2 i n t o 1 i n reducing tee - - - - - - - - - - - - - - - 7.60

Two 1 i n valves PVC - $13.00 each - - - - - - - - - - - - - 26.00

Two 1 i n 4.5' tees - $1.46 each - - - - - - - - - - - - - - 2.92

Four f t 2 i n pipe - $90.75/C f t - - - - - - - - - - - - - 3.63

TWO ft 1 i n pipe - $Q.oo/c f t - - - - - - - - - - - - - - .8LJ*

Total mater ia l f o r each p i t piping assembly - - - - - - - - 51.44

Labor f o r each p i t piping assembly (est) - - - - - - - - - 25.00

Tota l cos t of each p i t piping assembly - - - - - - - - - - 76.44

Average number of p i t s i n use P ick le P i t s - - - - - - - - - - - - - - - - - - 40 Tan p i t s - - - - - - - - - - - - - - - - - - - - - I 62 T o t a l ?its t o be equipped 102

Number of assemblies needed - - - - - - - - - - - - - - - 51 Tota l c o s t of use assemblies - - - - - - - - - - - - - - - $3,900

- - - - - - - - - - - - - -

143

TABLE^^. RECAP OF ESTIMATED EFFLUENT REUSE CONSTRUCTION COSTS

I t e m Material Labor

$4 , 500

Pump house 600 150

Outside Main 3 , 695 750

Ins ide Main 2,215 1,500

Poin t of use assemblies 2,625 s $13,635 $4,175

Tota l $17,810

It is not realist ic t o estimate any p r o j e c t c o s t on l a b o r and material alone. Overhead is always involved. 15% of the d i r e c t l abor c o s t f o r t h i s item, o r , i n t h i s case, $6,262.00.

It is customary t o add on t h e o d e r of

Grand t o t a l est imated cos t of d i s t r i b u t i o n system f o r reclaimed ef- f l u e n t wastewater.

T h i s estimated t o t a l of $24,072 f o r c o s t of equipment i n place compares very favorably with the estimated annual saving of $24,734, e spec ia l ly i n view of an t i c ipa ted equa l i ty i n operat ing cos t s . It m u s t be emphasized again, however , that some of the reuses envisioned could se r ious ly impair q u a l i t y and a careful program of eva lua t ion of each p o t e n t i a l use would most c e r t a i n l y have t o be undertaken before adoption.

USE OF FILTER PRESS CAKE AS FUEL

The 35% s o l i d s filter press cake that results from compaction of s o l i d s removed from t h e w a s t e stream is o r d i n a r i l y l and- f i l l ed . has a f u e l value, on a d ry bas i s , of about 6,000 BTU/lb, compared t o coa l a t 13,000 BTU/lb. (65%) make the filter cake un in te res t ing as a f u e l . is the presence of t r i v a l e n t chromium which poses t h e threat of formation of hexavalent chromium by oxidat ion dur ing combustion. highly t o x i c compound would make any burning of t h e f i l t e r cake a hazardous undertaking.

This material

The r e l a t i v e l y low f u e l value and high moisture content A further considerat ion

Production of such a

It is t h e conclusion, the re fo re , that the f i l t e r press cake is not a v iab le source of energy.

144

1 . Ramirez, E. R. and Clernens, 0 . A , , "Recovering Karketable Values from Beef Packinghouse Wastewaters, 'I WWZFlA Po l lu t ion Conference, Houston, Plarch 1976.

2. Ramirez, E. R. , "Zlectrocoagulation C l a r i f i e s Food Wastewater," Ohio Water Po l lu t ion Control Conference, 48th Annual Meeting, Toledo, June 1974 0

3 . Ramirez, E. R. , "Electrocoagulation Clarifies Food Wastewater," Deeds 6c Data, W'PCF, Apr i l 1975.

4. Ramirez, E. R. and Clemens, 0. A . , "Electrocoagulat ion Techniques f o r Prirnary Treatment of Several D i f f e ren t I n d u s t r i a l Types of Wastewater, ' I

49th Conference of WPCF, Flinneapolis, October 1976 . 5. Ramirez, E. R. , Barber, L. K . , and Clemens, 0 , A , , "Primary Physiochemi-

cal Treatment of Tannery Wastewater Using &2ectrocoagulation," 3Znd I n d u s t r i a l Waste Conference, Purdue Universi ty, blest Lafayet te , Play 1977.

6 . Ramirez, E. R. , and Barber, L. K. , " Cla r i f i ca t ion of Tannery Wastewater by E lec t ro f lo t a t ion ," Tannery Po l lu t ion Control Seminar, Mew England Tanners Club, iJovember 1977.

7. S tense l , H. D . , and Wright, J . D. , "Cost Ef fec t ive and Znergy E f f i c i e n t Wastewater Treatment ,'I 33rd I n d u s t r i a l klastewater Con€erence , May 1978.

8. Passveer, I. A m , "Simplified Wethod of Sewage Pur i f i ca t ion ," Report No. 26, Research I n s t i t u t e f o r Publ ic Iiealth Engineering, T.N.O., Netherlands .

9 . Zemaitis, W. L., and Jenkins, C. R . , "Biological Act iv i ty i n the Oxida- t i o n Ditch Fiethod of Waste Water Treatment," American I n s t i t u t e of Chemi- cal Engineers, 1971.

10, S tense l , M. D., Refl ing, D. R., and S c o t t , H. S . , "Carrousel Activated Sludge f o r Bio logica l Nitrogen Removal," Book, "Biological Nutr ient Re- moval." Ann Arbor Science, October 1978.

11. Sawyer, C. H., Wild, H. E. Jr., and i d a h o n , T. C. , " K i t r i f i c a t i o n and D e n i t r i f i c a t i o n F a c i l i t i e s , " 3 .P .A . Technology Transfer Seminar Fublica- t i o n , August 1973.

145

12, Ford, 3 . L., and Xlton, R, L. "Bemoval of O i l a.nd Grease from Industrial Nastewaters, 'I Chemical Engineering Deskbook Issue, October 1977.

13, Leather Tanning and Finishing Development Document, Draft, Revised, U .S .E .P . A . October 1978.

146

BIBLIOGRAPHY

1. "Aeration i n Wastewater Treatment", Water Po l lu t ion Control Feder t -L,S , washington: 1971.

2. "BASF Applies the Big Treatment", Chemical Week, Apri l 2, 1975.

3 . Burchinal, J . C., Jenkins, C . R . , "Ditches Provide E f f i c i e n t Treatment".

4.

5 .

6.

7.

a.

9.

10.

11.

12

14.

Environmental Science and Technology, 3: 11: 1170; 1969.

Horskotte, G . A , , Niles, D . G . , Parker , D . S., Caldwell, D . H . , and Horstokotee, D. G . , "Full-Scale Test ing of a Mater Reclamation System", Journal of Water Pol lu t ion Control Federation, 46 p. 181; 1974.

Jacobs, A , , "Loop Aeration Tank Design Offers Practical Advantages", Water and Sewage Works, October and November; 1975.

Koot, A. C, J. , and Zeper, J., "CARROUSEL, A New Type of Aeration-System With Low Organic Load, Water Research, Pergamon Press Vol. 6; 1972.

Maier, P . , "A Dutch Approach Toward Sewage Treatment and Automation of Sewage-Treatment P lants" , Progress i n Water Technoloa , Vol. 6; 1974.

Matsche, N . F., and Spa tz i e re r , G., " A u s t r i a n P l an t Knocks Out Nitrogen", Water and Wastes Engineering;, January; 1975.

Metcalf and Eddy, Inc., "Wastewater Engineering", M c G r a w- H i l l ; 1972,

Monn, E. P o , "Design and Maintenance of Extended Aeration Sewage Trea t- ment P lants" , Public Works, January; 1969.

Murphy, R . S. and Ranganathan, K. R., "Bio-Processes of t h e Oxidation Ditch When Subjected t o a Sub-Arctic Climate", Report No. IWR-27, I n s t i t u t e of Water Resources, Universi ty of Alaska, May; 1972.

"Operation and Maintenance of Wastewater Treatment F a c i l i t i e s " , United S t a t e s Environmental Pro tec t ion Agency, Washington, A u g u s t ; 1974.

Parker, H. W . , "Oxidation Ditch Sewage Treatment Process", Volume 6, Water Supply and Waste Disposal S e r i e s , U. S. Department of Transporta- t i o n , Apri l ; 1972.

Pasveer, I. A., "Simplified Method of Sewage Pur i f i ca t ion" , Report No. 26, Research I n s t i t u t e f o r Public Health Engineering, T. N. O . , Nether- lands .

147

15. Pasveer, I. A., "A C a s e of Filamentous Activated Sludge", Journal of Water Pol lu t ion Control Federation, 51, p. 134.0; 1969.

16. Procedure Manual f o r Evaluating t h e Performance of Wastewater Treatment P lan ts , Environmental Pro tec t ion Agency: 1974,

i n CARROUSEL Plants" , H20, February and March: 1974. 17. Sweeris, S. and Trie t sch , R., "Determination of t he Oxygenation Capacity

18. Zemaitis, W . L., and Jenkins, C. R., "Biological Act iv i ty i n t he Oxida- tion-Ditch Method of Waste Water Treatment", American I n s t i t u t e of C h e m i c a l Engineers: 1971.

19. Zeper, J. and DeMan, A . , "New Developments i n t he Design of Activated Sludge Tanks With Low B.O,D. Loadings", I.A.W.P.R., San Francisco, J ~ Y I 1970.

148

APPENDIX A

LETTERS FROM J. L. WITHEROW TO J. A. REID CONCERNING ANALYSIS OF STANDARD SAWLES FOR ANALYTICAL QUALITY CONTROL

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Industrial Environmental Research Laboratory - Cincinnati

Food and Wood Products Branch Corvallis Field Station 200 S.W. 35th Street

Corvallis, Oregod 97330

Ju ly 1, 1977

M r . John Reid A. C. Lawrence Leather Company 1 Bridge S t ree t Winchester, NH 03470

Dear John:

Your ana l y t i ca l r esu l t s f o r chrome, BOD5, and COD a r r i ved today, b u t no t the r esu l t s f o r NH3-N, N03-N, P, KJN, o r t o t a l P. The resu l t s sent are a l l correct,within one standard dev ia t ion o f the answers obtained by Qthers, except the BOD o f Sample 2, and t h i s was about 40% low. The lower BOD values o f sample 1, which i s s i m i l a r t o the discharge i s c e r t a i n l y fiore important t o the pro jec t ; however, being on the low s ide on t h i s h igher value might cause some problems i n opt imiz ing the axialation d i t c h operation.

Very t r u l y yours,

l%ack L. W i therow Pro jec t Off icer

cc: Ken Barber

149

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Industrial Environmental Research Laboratory - ClnCi~llldtl

Food and Wood Products Branch Corvallis Field Station 200 S.W. 35th Street

Corvallis, Oregon 97330

July 13, 1977

Mr. John A. Reid A. C. Lawrence Leather Co., Inc. 1 Bridge Street Winchester, N H 03470

Dear John:

Your analytic resu l t s fo r N H - N , NO - N, PO -P, K j N , and T-P arrived July 11, 1977. were 2.6, 1 . 2 , 0.13, 2.1 and 0.85 mg/l , respectively. values for the higher concentrations were 8.8, 6.7, 2.4, 38. and 4.28 mgjl, respectively. As you can see the PO -P were half the standard values and the lower KjN value was sf ight ly more than 2 times the standard value. T h i s suggests that 'di lut ion o f the samples f o r these analyses may have been i n error.

The standdrd valdes of the lower concentrations

Seven of your resul ts were "on the money."

The standard

Since we have been concerned over NH -N measurement techniques I checked and found one standard deviatioa for concentrations 3 and 4 was 0.4 mg/l and 1.3 mg/l, respectively. T h i s standard deviation was developed from an analyses by a number of laboratories in a "round robin" tes t ing program. the mean. the two methods of analyses.

This is about a 15% variation from Your data indicates accuracy and no difference between

Standard deviations f o r concentration 3 and 4 on PO4-P were The standard deviation f o r con-

Because of the large standard 0.04 and 0,4 mg/l, respectively. centration 5 f o r K . N i s 0.5 mg/l. deviation i n the Pd -P analyses we would no t re ject your two values.

Thank you f o r r u n n i n g these standards. was the problem I would appreciate knowing. the project or upon your request I will forward two additional ' se t s of standard samples to aid i n your quality control e f for t s .

The K . N vafue of 5.04 mg/l would be rejected. J

I f you f i n d dilution Toward the middle of

Very t ru ly yours,

I/ Jack L. Wi therow Food Products Staff

cc: Mr. Barber

15 0

APPENDIX B

151

(Please read Instructloris on the reverse before REPORT NO. 2. EPA-600/2-79-110

T I T L E A N D SUBTITLE

Processing Chrome Tannery Eff luent To Meet Best Available Treatment Standards

AUTHOR(S)

.awrenceK. Barber, Ernest R . Ramirez*,WilliamL. Zemaitis*"

PERFORMING O R G A N I Z A T I O N N A M E A N D ADDRESS

A. C . Lawrence Leather Co., Inc . Winchester , N . H . 03470

2. SPONSORING AGENCY N A M E A N D ADDRESS I n d u s t r i a l Environmental Research Lab. - C i n t i . , OH Off ice of Research and Eevelopment U.S. Environmental P ro tec t ion Agency Cincinnat i , OH 45268

5. SUPPLEMENTARY NOTES

**Envirobic Systems, New York, New York 10001 6. ABSTRACT

To s a t i s f y stream discharge requirements a t i t s Winchester, N . H . ,

completing) 3. RECIPIENT'S ACCESSION NO.

5. REPORT D A T E

Ju ly 1979 ( i s su ing date) - 6. PERFORMlNG O R G A N I Z A T I O N CODE

8. PERFORMING O R G A N I Z A T I O N REPORT N O

10. PROGRAM ELEMENT NO.

1 ~ ~ 6 1 0 11. CONTRACT/GRANT NO.

S 804504

13. TYPE OF REPORT A N D PERIOD COVERED

Fina l Report

EPA/600/12 14. SPONSORING AGENCY CODE

chrome t a n shear l ing tannery, t h e A. C . Lawrence Leather Co., Inc. s e l e c t e d primary and secondary systems t h a t g r e unique as appl ied t o tannery e f f l u e n t treatment i n t h e United S t a t e s . Primary c l a r i f i c a t i o n i s accomplished by means of coagulation and f l o t a t i o n , us ing e l e c t r o l y t i c as w e l l as mechanical micro-bubble generation. The secondary b i o l o g i c a l s e c t i o n i s a so- called CARROUSELYTM a techn ica l modification of t h e Passveer oxidat ion d i t c h . During t h e 12-month study, complete a n a l y t i c a l d a t a represent ing winter as w e l l as summer operat ing condi t ions were acquired along with operat ing c o s t da ta .

DESCRIPTORS ~ . I D E N T I F I E R S / O P E N ENDED TERMS

Leather Waste charac te r i za t ion Processing Wastewater Activated Sludge Process Economic Analysis

8. DISTRIBUTION STATEMENT 19. SECURITY CLASS (ThisHeporfJ' . . Unclasslf led 20. SECURITY CLASS (This page) RELEASE TO PUBLIC

This r e p o r t p resen t s t h e s e da ta and descr ibes t h e design and operat ion o f t h e system. Poss ib le app l ica t ions o f t h e same p r i n c i p l e s t o o the r tannery wastewaters are a l s o suggested.

c. COSATI i:ield/Group

68 D

21. NO. O F PAGES

162 22. PRICE

Q 11. s . GW,EQN~.IENT P RI N T I N G o r r i c k : iw - 657-060/534~ 15 2 EPA Form 2220-1 (Rev. 4- 77)

3 C 0

m Z <

c ..

rcn o w i o

C in - Z

cn in

m

0 - 2 -. 0

N 0-l 03

m Z i D i-

Documents

Processing Chrome Tannery Effluent to Meet Best Available … · 2018-06-13 · EPA-600/2-79-110 July 1979 PROCESSING CHROME TANNERY EFFLUENT TO MEET BEST AVAILABLE TREATMENT STANDARDS