Study On Wastewater Treatment In Tonghua Iron &Steel Company Coking Plant

Coking wastewater is a contain lots of poisonous and harmful matter, Which contains ammonia, hydroxybenzene, cyanide, NH₃-N, su.lf Ide, and organic oil in high concentration, it is one of the organic industrial wastewater that are hard to treat.Poisonous matter in the coking wastewater has a lot of harm to the environment, human body and agriculture. If the coking wastewater direct discharge will does a large harm to all ecotope, for example we will have less fish in the river and sea; reduce turn out of agriculture; more human diseases, affect all the human being living situation.Our country has experienced two phases In the treatment of coking wastewater. The first phases is to removal of hydroxybenzene, cyanides and COD, sulf ide, BOD etc; The second phase is eliminate NH₃-N, reduce harm to the environment.The widely technique used in the treatment of coking wastewater in our country is generally the activated sludge process, the principle of which Is to utilize their own metabolism course of bacteria in activated sludge to oxidize and decompose the organic materials in the wastewater, transforming organic materials into minerals and eventually into carbon dioxide and water in order to realize the harmless treatment of coking wastewater. After treatment by the activated sludge process, hydroxybenzene , cyanides and COD, sulfide, BOD in the wastewater all can up to the national wastewater discharge standard, but NH₃-N in the discharge wastewater is exceed the national wastewater discharge standard. So lately year come out a lot of improve process from the traditional ordinary activated sludge process, such as Oxidation Ditch , AB process, SBR process, A/0 process , A-A-0 process etc.This paper Introduce A-A-O process, through experiments found out that.