Abstract:

The tailrace of coking wastewater still have a variety of inert ingredients，which is an environmental risk and further limits its discharge or reuse safety，so it is necessary to study the feasibility of an advanced in-depth treatment technology. The actual wastewater was treated with a designed H₂O₂/UV fluidized bed reactor，and  COD removal and UV254 conversion were investigated under different dosages of H₂O₂，pH，aeration and light conditions，with TOC as an indicator to evaluate the degree of mineralization，and the oxidation of inert ingredients was analyzed by UV scanning，HPLC，GC/MS，IC. The results showed that under the conditions that the initial molar ratio of H₂O₂ to the COD was about 0.22，with slightly acidic and proper aeration，and high light reflection effective conversion of pollutants could be achieved，COD and TOC concentration could be decreased to about 20 mg/L and 10 mg/L respectively. During the process，the long-chain hydrocarbons，nitrogen-containing heterocyclic compounds，benzene and polycyclic aromatic hydrocarbons and other components were effectively transformed and mineralized，some were transformed into small molecule intermediate products，such as acetic acid and others，the toxicity of wastewater was greatly reduced and the effluent could serve as a source of reuse water.