PROCESS AND PLANT FOR BIOLOGICAL PURIFICATION OF COKING PLANT WASTEWATER

摘要

The present invention relates to a biological purification process for coke plant wastewater comprising nitrogen compounds, cyanides, phenols and sulfides. The coke plant wastewater is fed to a decontamination reactor having a gas treatment zone and a reaction zone with a material stream containing biomass to remove harmful substances that inhibit the nitrification process. The mixture fed to the deoxidation reactor is exposed to the gaseous oxidizing agent in the gas treatment zone. The oxidant-entrained material stream is fed to the reaction zone, where the cyanide and other noxious substances that inhibit the nitrification process are biodegraded. The material stream is withdrawn from the reaction zone and returned to the deoxidation reactor. In addition, the wastewater stream discharged from the adducting reactor is separated into a non-permeate stream containing biomass and a purified permeate stream by membrane filtration. The substream accompanying excess sludge from the non-permeate stream is removed. The non-permeate stream is recycled into the deoxidation reactor after the separation of the substreams. The permeate stream is further purified by a nitrification process and a subsequent denitrification process.