ELECTROCHEMICAL TREATMENT OF BIODIGESTER DISTILLERY EFFLUENT WITH AND WITHOUT AERATION

Abstract

Distillery wastewaters are considered as one of the serious pollution problems of the countries producing alcohol from the fermentation and subsequent distillation of sugar cane molasses. Over half a million liter of bio-digester effluent gets generated on a daily basis from a typical distillery producing ethanol from cane molasses. This effluent is difficult to treat by conventional biological treatment processes like activated sludge or anaerobic lagoons. Electrochemical treatment is one of the emerging technologies in secondary and tertiary treatment. It was employed for the removal of color and COD from the bio-digester distillery effluent. The applied voltage was kept above 12 V while the current density used was varied from 50 to 90 A I11-2 for the present study. The overall treatment time employed for the treatment process was 4 h. Six number of electrodes with an inter electrode distance of 10 mm were used in the present study. The electrochemical treatment yielded a maximum COD and color removal of —80 and —90%, respectively. Aeration was also employed along with the electrochemical treatment to see its effect on the removal efficiencies. Removal efficiencies —75% COD and — 80% color) were found to be lower in case of aeration as compared to that without aeration.