Distillery effluent: Problems and prospects-A review

Distillery effluent generally known as spent wash is considered one of the worst pollutants produced by industries. For every litre of alcohol 12–15 litres of spent wash is produced which has got appreciable amounts of organic load, high biological oxygen demand (BOD), chemical oxygen demand (COD) and is highly acidic in nature. To decrease the BOD and COD values, several distilleries have installed the biomethanation units but still contains high concentrations of organic pollutants and can not be discharged directly. Spent wash being plant originated, contains large quantities of soluble organic matter and plant nutrients, therefore, spent wash if utilized rationally and in appropriate concentration for crop production can prove to be a good source of nutrients and is expected to solve the problem of waste disposal. The purpose of this review is to discuss and summarize the available data on problems and prospects of distillery spent wash.