Keywords: caramel, composting, disc-tubes, molasses, water pollution, reverse osmosis, pressmud, zero discharge, effluent discharge, ethanol distilleries, spentwash colour removal, India, water reuse, water quality
The need for a novel method for achieving zero effluent-discharge status for ethanol distilleries: spentwash colour removal by reverse osmosis
Sustained industrial scale production of ethanol in India is dependent on the earliest possible implementation of zero effluent discharge. High pollution parameters of effluent made it commercially impossible. An urgent need for developing a method to attain a zero discharge status for distilleries was essential. The presently tried and tested methods had limitations for conclusive disposal of spentwash effluent. Application of Reverse Osmosis was tried. However, only Rochem's DT Reverse Osmosis configuration was effective. It reduced the effluent volume. The reduced volume effluent could be conclusively composted. It also enabled recovery of reuse-quality colorless water to the extent of 50% of original volume of effluent. This technique succeeded in achieving commercially viable means for zero-discharge.