BIOLOGICAL TREATMENT OFPOLYACRYLONITRILE WASTEWATERCONTAINING SODIUM THIOCYANATE BYMIXED BACTERIAL CULTURE
应用混合菌种处理腈纶废水中的硫氰酸钠

A kind of mixed bacterial culture able to treat thiocyanate-containing wastewater, was isolated from sludge.This culture consists of both aurotrophic and heterotrophic bacteria including Thiobacillus thioparus, Thiobacillus intermedius, Arthrobacter sp., Pseudomonas sp. and Azotobacter sp.. The culture can be used to decompose sodium thiocyanate with high removal efficiency. In addition it can also be able to remove acrylonitrile as well as acetone and isopropyl alcohol. The culture has been used directly for biological filming in secondary submerged filter to treat polyacrylonitrile wastewater containing sodium thiocyanate. Pilot run has been normal for ten months, with a hydraulic loading of 9.615 m3/m3/day, a CODCr loading of 3.12 kg/m3/day and a BOD5 loading of 1.91 kg/m3/day. Average removal efficiency of CODCr stands 81.59%, BOD5 82.63% and NaSCN 95.67%. Sodium thiocyanate content in effluent is down to<2 mg/l. Removal of other pollutants are satisfactory too, and quality of effluent meets discharging standards of the area.