Application of Double Membrane Method in Water Reuse Engineering for Advanced Treatment of Food Wastewater
The dual membrane method(ultrafiltration+reverse osmosis)was used to deeply treat the effluent from the secondary sedimentation tank of a food enterprise's sewage station.The treated wastewater was reused in the bathroom and cooling tower,achieving the goal of saving tap water.The disc filter system was used before ultrafiltration membrane in or-der to remove suspended solids(SS)and add NaClO to reduce blockage by chemical oxygen demand.The water flow rate of a single ultrafiltration membrane system was 20 m3/h.The ultrafiltration recovery rate was about 90%,and the turbidity of the produced water was below 0.3 NTU.Scale inhibitors and reducer were used before reverse osmosis system to avoid the membrane from oxidizing.The water flow rate of a single set of reverse osmosis system was 14 m3/h.The reverse osmo-sis recovery rate was about 70%.The conductivity of reverse osmosis products was less than 80 uS/cm,which could meet the requirements of water reuse.
Food wastewaterReclaimed water reuseDouble membrane methodUltrafiltrationReverse osmosis