Study On Treatment Of Coke Wastewater By UASB-Bio-contact Oxidation-Coagulation Sedimentation Joint Process

At present, coke industry is developing very quickly in our country, coke yield reached 1.78×109t/a, which account for 45.6% of total amount in the world. China had become the greatest coke production country. In the production of coke, a great deal water was used and most char wastewater was produced. About 2.8×109t/a char wastewater was discharged in our country.The char wastewater contained a lot of hardly degradable organic compounds, and it was difficult to be biodegradable. Components in the char wastewater were ammonia, cyanide compound, sulfur compounds, thiocyanate, phenolic compounds and heterocyclic compounds etc. So the wastewater was high ammonia, phenolic, oil, poisonous and had more biological inhibition compounds and hardly degradable compounds, which belonged to a typical high concentration, pollution, poisonous and hardly degradable industrial wastewater.UASB-bio-contact oxidation-coagulation sedimentation combined process was used to treat the wastewater. Based on the result of the experiment, UASB reactor adopted the granular sludge which was used to treat the juice wastewater as the inoculation sludge, the temperature was controlled at 30±1℃, and the influent organic loading was adding gradually. About 42 days, the granular sludge had finished the domestication, at this time, COD concentration of effluent was 1000mg/L. Bio-contact oxidation reactor used activated sludge in biofilm culturing, About 15 days, the biofilm could be domesticated at room temperature. The COD concetration, ammonia and pH of the effluent were 200mg/L,10mg/L and 6.8-7.2, the COD. the NH3-N removal efficiency was 80%.Coagulation sedimentation was adopted to further purify the effluent, and the COD concetration of the effluent was 40mg/L, So the COD removal efficiency of the combined process was 98.8%. which can reach the first class standard of GB8978-1996.Acoording to the result of the experiment, the kinetic equation of the UASB was T/q=0.01397+0.05335, R=0.9909, and the kinetic equation of bio-contact oxidation was...