Performance evaluation of the common effluent treatment plant and treatability study for the optimization of chemical dosing

Author(s): Rajendra Singh Thakur, Rubina Chaudhary, Kishore Malviya

The present study was based on performance evaluation of Common Effluent Treatment Plant (CETP) and optimization of chemical dosing in the plant. Flowbased composite sampleswere collected fromcollection tank, primary clarifier, secondary clarifier, aeration tank and final treated water. Testing was required to obtain the following necessary design and operating parameters pH, chemical oxygen demand (COD), total dissolved solid (TDS), total suspended solids (TSS), settling time (Min.) sludge generation (Volume). Total volume of sample was to monitor the treatment efficiency at different stages of treatment plant. Collected samples were analyzed in the laboratory. Water qualitywas determined after treating thewastewater with combination of physicochemical treatment.The study of the coagulation-flocculation process using various commercially available coagulants such as lime, ferrous sulphate and alum.Optimization pH and chemical concentration in the jar-tests. Performance and optimization of chemical dosing, doing trials with lime&FeSO4 on the inletwater. Experimentswere performed to replace FeSO4with alum. Treatibility study using lime with alum gave maximum reduction in COD, colorwithminimumsludge generation, as compared with FeSO4. From the experiments it was observed that, optimized dose of lime should be increased to 8 - 12mg/l and the existing dosing of alum60 - 85mg/ l to ensure proper removal of the suspended solids. Cost estimation was done, of the above coagulants after evaluating their performance.

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