PERFORMANCE EVALUATION OF MODIFIED SEQUENCING BATCH REACTOR (MSBR) FOR TANNERY EFFLUENT TREATMENT

The tanning industry in Tamilnadu is familiar with its being a potentially pollution-intensive industry. Tanneries are such industries which contributes a major part in water usage. The results of the lab analysis of the industrial wastewater effluent show that the contamination is mainly due to high levels of Sulfides with an average of 1288mg/l. Chromium (trivalent) in the tanneries effluent range from 1.5- 157mg/l in the end-of-pipe effluent and the level of chromium(Cr) from the chrome path effluent is around 10064mg/l. Analysis of COD and BOD during the process show that the levels of COD ranged in between 1564mg/l – 53056mg/l with an average value of 13894 mg/l. However, the BOD values ranged between 420– 27050mg/l with an average value of 4704mg/l which are above the limits of the standard for discharge to the wastewater sanitary network, while values of TSS, settleable solids, phosphorous and total Nitrogen(N2) are within the limits. The results obtained from the biological treatment indicates the high effectiveness of the process to reduce mainly TSS, COD and BOD besides appreciable reduction of other parameters mainly sulfides and nitrogen. The overall results of the treatability study indicate that the suspended solids are removed with almost 99% efficiency while the removal of COD & BOD levels reaches 93-95%