Removal of foaming from industrial wastewater treatment plants

Water Practice and Technology - Tập 10 Số 3 - Trang 415-423 - 2015
Nastaran Khodabakhshi1, Gholamreza Asadollahfardi1, Elnaz Shahriarinia1
1Environmental Engineering Department, Kharazmi University, Hesarak Karaj, Teheran, Iran

Tóm tắt

Proper operation of activated sludge systems is very important and depends on physical, chemical, and biological parameters of wastewater. In this study, some problems were studied in an existing wastewater treatment plant of a fish-canning factory located in Tehran where thick, brown, stable foam was observed in aeration and clarifier tanks. The effluent of this plant was higher than the standards of the Department of the Environment of Iran, and the pH in aeration tanks was lower than 5. As opposed to other researchers in solving the foaming problem, in this wastewater treatment plant, lime was used instead of organic polymers and other inorganic coagulants. The pH of aeration tanks was adjusted to between 6.5 and 8.5 with an injection of 500 mg/L (47.5 kg/day) lime in the chemical sedimentation tank. It appeared that the solid retention time in this plant was high. Therefore, the rate of return sludge in the aeration tank of the second stage was reduced by about 20%. Foaming was removed in 18 days. During this time, chemical oxygen demand (COD) of effluent went from 500 to 65 mg/L, which indicated 87% reduction. The estimated costs of using lime for removal of foaming were about 0.0029 Euros/day (0.004 dollars/day), which is very low.

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Tài liệu tham khảo

Davis, 2010, Water and Wastewater Engineering: Design Principles and Practice

Eckenfelder, 2003, Industrial Water Pollution Control, 3rd edn

Ekama G. A. Marais G. Blackbeard J. R. 1985 Exploratory Study on Activated Sludge Bulking and Foaming Problems in Southern Africa. WRC Report No.114/1/85. Pretoria, South Africa.

Fryer, 2011, Evaluating the measurement of activated sludge foam potential, Water, 3, 424, 10.3390/w3010424

Griffiths, 2010, Foaming organisms in sewage treatment - friend or foe: victim of bad publicity

Hug T. 2006 Characterization and Control of Foam and Scum in an Activated Sludge System. PhD Dissertation, Swiss Federal Institute of Technology, Zurich.

Jenkins, 2004, Manual on the Causes and Control of Activated Sludge Bulking, Foaming, and Other Solids Separation Problems, 3rd edn

Mamais, 2011, Foaming control in activated sludge treatment plants by coagulants addition, Global NEST J., 3, 237

Noutsopoulos, 2006, Effect of solids retention time on Microthrix Parvicella growth, water SA, 32, 315

Pugh, 2005, Experimental techniques for studying the structure of foams and froths, Adv. Colloid Interf. Sci., 114–115, 239, 10.1016/j.cis.2004.08.005

Re, 2010, Causes and control of foaming in the secondary process

Roles, 2002, The influence of PAX-14 on activated sludge systems and in particular on Microthrix parvicella, Water Sci. Technol., 46, 487, 10.2166/wst.2002.0521

Rossetti, 2005, ‘Microthrix parvicella’, a Filamentous bacterium causing bulking and foaming in activated sludge systems: a review of current knowledge, FEMS Microbiol. Rev., 29, 49, 10.1016/j.femsre.2004.09.005

Shariat Panahi, 2001, Quality of Water and Wastewater Treatment, 6th edn

Takdastan, 2009, Problems in operation of wastewater treatment plants using activated sludge and its control of the country

Turovskiy, 2006, Wastewater Sludge Processing, 1st edn, 10.1002/047179161X

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Thông tin xuất bản

Water Practice and Technology

Tập 10 Số 3

415-423

Thông tin tác giả