TREATABILITY STUDIES OF DAIRY WASTE WATER BY 3UASB AT MESOPHILIC TEMPERATURE FOR DIFFERENT OLR

An evaluation of anaerobic treatment of Dairy wastewater using an up flow Anaerobic sludge Bed (UASB) reactor at mesophilic temperature 27-35°C was conducted. Wastewater from AAVIN Dairy in pachapalayam, coimbatore with an average of 5500g COD/L, (COD = chemical oxygen demand) and a high concentration of total solids (up to 3015 mg/L) with pH of 8.5- 9 was subjected to anaerobic treatment in an UASB reactor. The startup period, which was indicated by gas production and stabilization of COD reduction was measured. The organic loading rate was started at 2.5gCOD/l/d, the maximum methane yield was 0.6 l/g. COD removed at and organic loading rate of 2.5 g COD/l/d was 78%. The maximum treatment efficiency (TE) in terms of COD reduction achieved was 90% at a hydraulic retention time (HRT) of 43 d. Total solids (TS) removal was effective and pH from the effluent oscillated around 7with a notable decrease from 7.8 to 6.2 at HRT of 0.5 d. Based on these observations, the UASB process has potential in treating combined effluent from aavin dairy Coimbatore. The organic loading rates are increased by 0.5gCOD/l/d and the readings are observed for 3gCOD/l/d and 3.5gCOD/l/d.