Mahella Process discreption

8/8/2019 Mahella Process discreption

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MISR SPINNING & WEAVING CO.

(Mehalla Kubra)

INDUSTRIAL WASTE WATER TREATMENTPLANT

CAPACITY: 50,000 m/day-

PRETREATMENT

40,000 m3/day SECONDARY & POST

TREATMENT

DESIGN CRITERIA & PROCESS

DESCREPTION


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Characteristics of waste water of Misr spinning and weaving company.

Influent wastewater characteristics:

Flow : 2.200 m3/h 50.000 m3/d

COD : 530 mg/l Load 26.500 kg/d

BOD : 242 mg/l Load 12.100 kg/day

BOD/COD >0.46

TSS : 384 mg/l Load 19,200 kg/d

pH : 9 11

Color : 200 Units


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GENERAL OVERVIEW OF THE PLANT

Waste Water

SECONDARY

TREATEDPRETREATED

WATERWATER

ACTIVATED

SLUDGE

EFFLUENT TO BE DISCHARG

EXCESS BIOLOGICAL SLUDE

PRIMARY

WASTE

SLUDGE

DEWATERED SLUDGE FOR DISPOSAL

PART A

PRETREATMENT

-Screening

- Oil & grease

skimming

-Pumping

-Conditioning

-Adsorption on

Biomass and Pac

- Neutralization

-Coagulation

-Flocculation

- Sedimentation

PART B

BIOLOGICAL REACTOR

Aeration

sedimentation

Addition of powdered

Activated Carbon and

Bio-Solids Wasting

Nutrient removal (N & P)

PART D

SLUDGE TREATMENT

Sludge

Stabilization/

Thickening/ Dewatering

PART C

POST TREATMENTChlorination for

disinfections &

Oxidation of

COD/Color removal

sand Anthracite

filtration


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AL Mehalla

project is an industrialwastewatertreatment

plant (Textile Waste Water)with acapacityof50.000 m3/day.

We have split up theproject in 4parts:

Par t A Pretreatment

Par t B Bioreactors aerobic LUCASSystem

Par t C Chlorination & Filtration.

Par t D Sludge treatment.


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Part A

The Pretreatment consists of:

Oil & GreaseSkimming

ManualCoarseScreening

MechanicalFineScreening

Conditioning and adsorption on activated sludgeand PAC

pHcontrolling system.

Coagulation and flocculation

Pre-settling.


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Pretreatment Is physicochemical treatment to:

Equalization & discoloration to the WW byretained biosludge in Bufferingtank byMixing & aeration in aerobiccondition.

Neutralization toadjust pHof the influent WW.byadd acid (mainly)Due to the WW have high alkalinepHrange 9 -11with facilitation ofbaseadding in caseofWW.pH shallbeless than 7.00

Coagulation bycoagulant ( Alum orFerricchloride) toenlarge the sizesuspended solids

Flocculation byflocculent ( Anionicpolymer) to increase the settiability ofthe suspended solids.

Sedimentation ofsuspended solids including biosolids and suspendedsolids in settlement tanks.


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Estimation of Removal efficiency after Pre-treatment

by Physicochemical method :

COD : 400 mg/l removal % 25%

BOD : 200mg/l removal % 20%

TSS : 200 mg/l removal % 50 %

Color : 40 unit removal % 80 %

pH : 7 9


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Part B

Biological Reactors Two Lane LUCAS System

Thebiologicalreactor is divided into2lanes each laneconsists of3 basins.

Allbasins areequipped with surfaceaerators toprovide necessaryoxygen for

treatment process. Allbasins areequipped with submersible mixers toassure good mixing of the

waterwith activated sludgeand toprevent dead zones in thebasins .

Waterlevels arecontrolled by LevelSwitches toprevent overflowof thebasins

Oxygen concentration in thewater is controlled byOxygen Meters toreservealways acertain amount ofoxygen in thewater.

At any timeoxygen concentration is higher than acertain point surface

aerators will stopwhich saveenergy. At that time mixers are stillworking toassure mixing of thewaterwith activated sludgeand keep thewater in asuspension phaseall the time

Basins arealsoequipped with submersiblepumps to transferexcess sludge tobuffertank and forsludge treatment.( part D)


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LUCAS Hydraulic scheme

- The 3 units are hydraulically connected

- Thus hydraulic connections combine the individual units into a single tank

lue t lue t

I lue t I lue t

Aerati sedime ta ti Aerati Aerati sedim e ta ti

Ai r Bl ers

E ce ss S lud e

Efflue t Efflue t

I flue t I flue tI flue t I flue t

Aerati sedime ta ti Aerati Aerati sedim e ta ti

Ai r Bl ersAi r Bl ers

E ce ss S lud e

LUCAS Leuven University Cyclic Activated sludge


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LUCAS Cyclic

operation

Mainphase 1

sedimentationEffluentaerationaeration

Influent

sedimentationEffluentaerationaeration

Influent

Mainphase 2

Effluentaeration aerationsedimentation

Influent

Effluentaeration aerationsedimentation

Influent


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Bio-solids production (per lane)

Excess biosolids production 2.000 kg MLSS/day

Excess biosolids flowrate 200 m/d

WasteTime 8 hrs

Excess sludgeflowrate 25 m/hr


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SLUDGE WASTING

Theexcess biosolids ofthe LUCASreactor(of the2lanes)arepumped by4 submersiblepumps (twopumps

in each lane)with acapacityof25 m3/h (each) back tothePreTreatment (PART A) and / or toSludgeTreatment (Part D) .

Theexcess biosolids to(Part A )willact as anadsorbents forcolorreagents and otherorganics withthePAC.

The total sludgeproduction willbe:13, 600 kg DS/day.


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Rinsing phase:

Beforeacompartment becomes a settling compartment and effluentis discharged through its launders, a short rinsing phase is insertedtorinse thelaunders.This rinsing water, which contains suspended

solids, sludge, flows by gravity to therinsing pit.

Supernatant from the sludge thickeners and filtrateofthe sludgedewatering arealsoflowing to therinsepit.

Therinsing pit serves thus as a storage tank fordifferent internal

waters whosequality is not good enough to send them immediatelyto theeffluent.and it retrun back tobiologicalreactors.


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Characteristics of Treated Water after LUCAS aeration system

( Part B )

Flow : 1.666 m3/h 40.000 m3/d

COD :


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(Part C)

POST TREATMENT

Chlorination & Gravity sand filtration.

To get an extrapure treated waterforreuses asirrigations purposes.Theeffluent flows by gravityfromthe sedimentation compartment ofthe LUCAS system totheChlorineContact Tank fordisinfection and reductionoftotalcoliform count to theallowableregulation low.

The disinfected effluent then flows into the influentfiltration tank and willbepumped tofiltration units.


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reproduced or revelealed toot hersexcept in accord withcontract o r other writtenpermissionso f

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Thisdrawingist heconfidential propertyo f AT RL AUGLO AL AT RT ! NOLOGYNV. Informationandknowhowhereon are confidential andmaynot be used,

Any reproductionsi n wholeor inpart i ncludingshopdrawingsshall bear or refer tot hisstamp.


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Characteristics of final effluent treated water

After Chlorination & filtration (Part C )

Flow : 40.000 m3/day.

COD : 80 mg/l

BOD : < 30 mg/l

TSS : < 30 mg/l

pH : 7 9

Color : freeofcolor

Totalcoliform : < 5000CFU/ml.


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(Part D)

SLUDGE TREATMENT

The sludge treatment systems is consists of3 stages :

1 -Sludge stabilization.

2-Sludge thickening.

3 -Sludge dewatering.


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Excess sludgefrom thebiological tanks, in function ofthecyclicoperation and in function of the sludgegrowth in thepackageplant toThebuffer tank wherewe use the sludgeand its content ofactivated carbon

PAC in theprocess ofdiscoloration of incoming wastewaterand then all the sludge including biologicalsludgeproduces from thereactors, and the sludgeproduced from thecoagulation and flocculationprocess which removes about 50-75% ofsuspended

solids in the sedimentation basins settled in both tanksand pumped to the sludge stabilization tank .


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sludge stabilization:

The stabilization tank is designed toprovidean additionalaerobicsludgeage and thus highersludge mineralization.Theaerobicdigesters areoperated with intermittent aeration toallowfor

simultaneous nitrification and denitrification therebyensuringalkalinityrecoveryand preservation and toprevent anaerobicconditions that could releaseback theaccumulated phosphorus.

The digestertank is intermittentlyaerated and mixing with a surfaceaerators & submersible mixers .This ensures excellent suspending

and homogenization and at the same time sludgeaeration is doneathigh efficiency. And by sludge stabilization the dry solids content arereduceby20%

Sludgeconcentration in stabilization tank 10-15 gm/l


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sludge thickening

Thefeed sludgefrom stabilization tank. is allowed to

settleand compact, by thickening process being

enhanced bya slow turning rake mechanism with bottom

scrapers.The thickened sludge is withdrawn from the

bottom of the tank at 3% as DScontent.The supernatant

water is returned to therinsepit of thebiologicaltreatment

The thickened sludgewillbepumped to the2 new

dewatering filterbelt


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sludge dewatering

The thickened sludgefrom both sludge thickeners. isallowed to mixed with cationicpolymer toenhance the

sludge dewatering by twofilterbelt press units to

produce dewatering sludgewith 15-20% DS.


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Mahella Process discreption