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* Corresponding author: P. S. ArunadeviPG and Research Department of Zoology, Sri Vasavi College, Erode – 638 316. Tamil Nadu, India  

ISSN: 0976-3031

RESEARCH ARTICLEREMOVAL OF NUTRIENTS FROM DAIRY WASTE WATER BY USING TWO PHASE UASB REACTOR

*Arunadevi, P. S and Nagarajan, V

PG and Research Department of Zoology, Sri Vasavi College, Erode – 638 316. Tamil Nadu, India 

ARTICLE INFO ABSTRACT

Removal of nutrients from dairy processing wastewater was studied by anaerobic two-phaseUASB treatment method. Dairy wastewater is rich in nutrients especially nitrogen and  phosphorus. This may due to addition of cleaning agents. The anaerobic treatment method for treating dairy wastewater was considered to be better option than aerobic method. At the

same time, maximum removal of nutrients was a problematic one. Thus in the present

investigation long-term study (up to 249 days) was conducted. The study period was divided into seven phases based on their Organic Loading Rate (OLR) and Hydraulic RetentionTime (HRT). From the results, it was noted that maximum percentage removal of nutrientswas observed in the phase II. Utilization of organic nitrogen was markedly higher than that

of phosphorus. The reduction rate was reduced when the OLR is raised and also withreducing HRT. This indicates that the decrease in nutrient utilization at higher OLRs isattributed to higher flow and reduction in contact time between nutrients and microbes aswell as to nutrient wash out.

INTRODUCTION 

Wastewater from dairy processing units is rich in biodegradable organic molecules, nutrients and usuallycontains high level of fat and proteins. So, dairy industry isnoted as significant contributor to pollution. The organicstrength of wastewater is higher than that of community waste.

The environmental impacts of these units can be very high,especially due to the discharge of very large flows of waste-water with high content of organic matter and nutrients (N and 

P), which has been the cause of numerous eutrophication problems worldwide (Kalchen and Brev, 1999; Vonder Molenet al., 1999). Moreover, in lagoons and swamps, these two

factors (nitrogen and phosphorus) insist algae and microorganisms co-exist, so that the O2 levels of these biotypes are affected.In the present investigation, the dairy

wastewater was treated with anaerobic two-phase UASBreactor. Anaerobic treatment of wastewater is better option for high removal of organic matter and also for energy recovery

 process. The nutrient removal rate was also calculated and reported.

MATERIALS AND METHODS

A laboratory scale two-phase anaerobic digestion system was

used in this study. It consisted of, i) an acidogenic reactor for the purpose of pre-acidification of the influent and ii) anUpflow Anaerobic Sludge Blanket (UASB) with internal

 packing column as the methanogenic reactor.Total reactor  performance was monitored for 249 days. It was dived into

seven phases, based on their OLR and HRT. The HRT wasconstant for the first five phases; the HRT for acidogenic

reactor was 2 the methanogenic reactor 2.5 days.

The OLR was increased by increasing the concentration of the

effluent. In the VI and VII phases, the OLR was increased byreducing the HRT. During the entire operational period, the

reactor performance was monitored carefully.

The parameters were analyzed according to the standard methods for the examination of water and wastewater analysis

following APHA (1998). TKN was measured by Macro-Kjeldhal method. Total phosphorus was calculated by Vanado-Molybdate yellow colour method.

RESULTS AND DISCUSSION 

Dairy wastewater was often characterized by high organiccontent. At the phase-I diluted effluent was fed into the reactor and it was gradually increased by increasing concentration of 

the effluent in the subsequent phases (Table 1).

During the experiment, utilization of organic nitrogen wasmarkedly higher than that of phosphorus. Higher utilization of nitrogen in comparison with phosphorus during the anaerobictreatment was reported by Subramanian and Sastry (1989) and also by Banu et al. (2006). The utilization rate was higher atthe initial phases, thus indicating the source of nitrogen was

essential for their cell synthesis. Phosphorus was also needed  but at a lesser extent.

Baloch et al. (2007) stated that high consumption (up to 16%)of influent NH4- N was observed in the acidogenic dominant

zone and it is believed that this amount of Nitrogen wasassimilated for the synthesis of new microbial growth.

Utilization of both nutrients was high at the Phase II. Thereduction was 59-72% for Total Kjeldahl Nitrogen and 54-58% for Total Phosphorus.

 Available Online at http://www.recentscientific.com

 International Journal 

 of Recent Scientific

 Research  International Journal of Recent Scientific Research 

Vol. 4, Issue, 6, pp.1001– 1002, July, 2013 

 Article History:

Received 13th, June, 2013

Received in revised form 25th, June, 2013

Accepted 14th, July, 2013

Published online 30th July, 2013

 Key words:Sprouts, microorganisms,local markets,Chennai. 

© Copy Right, IJRSR, 2013, Academic Journals. All rights reserved.

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 International Journal of Recent Scientific Research, Vol. 4, Issue, 7, pp. 1001 - 1002, July, 2013  

1002

Increased organic loading rate at the Phase III reduced the

utilization of Nitrogen from 72 to 56%. Similarly, thePhosphorus utilization also fell from 58 to 47%. But, in thesubsequent phases, the reduction rate was maintained between

50-60% for TKN and 30-40% for Total Phosphorus. This wascontinued up to the organic loading rate of 4.01-4.21 kgCOD/m3/day at 2 days HRT for acidogenic phase and 2.61-

2.75 kg COD/m3/day at 2.5 days HRT for methanogenic phase.

The reduction rate was further reduced when the OLR was

raised by reducing HRT. Marked reduction was observed atthe Phase VII with 12 hours HRT for the acidogenic reactor 

and 15 hours for methanogenic reactor. The reduction rate wasonly 39-41% for TKN and 19-26% for Total Phosphorus. Thedecrease in nutrient utilization at higher OLRs can be

attributed to higher flow rate of the wastewater and theconsequent reduction in contact time between nutrients and microbes as well as nutrient washout.

 Acknowledgement 

The financial assistance through Jawaharlal Nehru

Scholarships for Doctoral Studies, by Jawaharlal Nehru

Memorial Fund is gratefully acknowledged.

References

APHA (1998). “Standard Methods for the Examination of water and wastewater”. 20th edition. American Public

Health Association, Washington, DC.Kalchen R.K. and Brev I.S. (1999).“Long-term eutrophication

development in five coastal lakes of the Bulgarian Black 

sea region”. Water Sci Technol., 39:(8), 1235-39.Van der Molen D.T and Portielje R. (1999). “Multi-lake

studies in the Nettherlands: Trends in eutrophication”.

Hydrobiologia, 408: 359-365.Subrahmanyam Y.V. and Sastry C.A. (1989). “Attached versus

suspended biomass ativity in upflow anaerobic filters”.J. Ins. Eng., 9: 27-32.

Banu R.J., Kaliappan S. and Beck D. (2006). “High rateanaerobic treatment of Sago wastewater using HUASB

with PUF as carrier”. Int. J. Environ. Sci. (Suppl. Winter),3:(1), 69-77.

Baloch M.I., Akunna J.C. and Collier V. (2007). “The

 performance of a phase separated granular bed bioreactor treating brewery wastewater”. Biores. Tech., 98, 1849-1855.

Table 1 Performance of two phase uasb reactor  

PHASES INITIAL

Nitrogen

mg/l

FINAL

Nitrogen

mg/l

% OF

REMOVAL

INITIAL

Phosphorus

mg/l

FINAL

Phosphorus

mg/l

% OF

REMOVAL

PHASE I Starter Starter Starter Starter Starter Starter 

PHASE II 37-48 16-12 59-72 22-26 10-12 54-58

PHASE III 56-66 27-29 54-56 30-38 17-20 43-47

PHASE IV 92-105 42.4-40.6 56-61 46-52 36-34 39-40

PHASE V 112-127 52-57 53-55 47-57 30-33 36-42PHASE VI 91.6-104 42.4-47.5 46-45 41-52 30-34 17-33

PHASE VII 85-91 52-55 39-41 37-46 30-34 19-26

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