Treatment of distillery spent wash by combined UF and RO processes

The present study deals with the treatment of distillery spent wash by an ultrafiltration (UF)
membrane followed by reverse osmosis (RO) membrane on a pilot scale membrane setup.
The performance of the system was evaluated by varying applied pressure on the thin-film
composite polyamide (TFC-PA) UF and RO membranes. In the first stage, UF experiments
are carried out for concentration of effluents by removing the suspended solids (SS). RO has
effectively separated the total dissolved solids (TDS), chemical oxygen demand (COD),
biochemical oxygen demand (BOD), sulphate and potassium with the rejection efficiency of
97.9%, 96.8%, 97.9%, 99.7% and 94.65%, respectively. UF was effective for the separation of
SS with the rejection efficiency of 95.5%. The pollutant level in permeate are below the
maximum contaminant level as per the guidelines of the World Health Organization and the
Central Pollution Control Board (CPCB) of India specifications for effluent discharge (less than
1000 ppm of TDS and 500 ppm of COD).