Treatment of spent wash in anaerobic thermophilic suspended growth reactor (ATSGR).

Pollution through spent wash is a major problem in India. There is an urgent need to develop wastewater treatment technologies for safer disposal. In the present investigation, an attempt has been made to examine a few aspects of thermophilic anaerobic digestion of spent wash collected from a distillery. The study was carried out in a 4 liter laboratory scale anaerobic thermophilic suspended growth reactor After the successful startup, the organic loading was increased stepwise to assess the performance of the reactor. During the study period, biogas generated was recorded and the maximum gas generated was found to be 11.9 liter at an organic loading rate (OLR) of 29 g COD/l. A 500% increase in the volatile fatty acid (VFA) concentration (1850 mg/l) was observed, when the OLR was increased from 29 to 30 g COD/l. During the souring phase the removal of COD, total solids (TS) and volatile solids (VS) were in the order of 52%, 40% and 46% respectively The methane content in the biogas varied from 65% to 75%.