Study On Phenolic Wastewater Treatment Technology

Phenolic compounds is one of the prototype poison, have toxic effects on humans and other organisms. Therefore, the phenolic wastewater is one kind of the very serious harm of industrial wastewater. At present, it is difficult to deal with phenolic wastewater by using biochemical method to satisfy the discharge standard, and the cost of chemical and physical and chemical is higher. Therefore, it is urgent to develop new effective technology to deal with the phenolic wastewater. In this paper, according to the discharge amount and discharge standard of the phenolic wastewater from the phenol/acetone plant in Jilin Petrochemical Company, the high concentration wastewater was treated with homogeneous wet peroxide oxidation technology, heterogeneous WPO technology and internal electrolysis, respectively. Moreover, the active carbon supported catalysts were studied. Results were showed as follows:(1) During the treatment of phenolic wastewater using by homogeneous WPO, removal rate of COD increased with increase of temperature at start stage, then decreased. Removal rate of COD increased with increase of react time until equilibrium. Initial pH value of the wastewater affected formation of the hydroxyl. Moreover, addition of active carbon favored the improvement of removal rate of COD. The best treatment result of the wastewater was obtained under reaction temperature of160℃, reaction time of60min, initial pH of3.5, Fenton reagents in proportion of [H2O2]/COD=1.2, the removal rate of COD was up to90%.(2) During the treatment of phenolic wastewater using by heterogeneous wet peroxide oxidation method, catalysts CuO/AC were prepared by impregnation method and co-precipitation method, respectively. Using CuO/AC prepared by impregnation method, when the H2O2addition is2500mg/L and reaction time is60min, the removal rate of COD was up to95%. Moreover, the catalyst reused for5times, the removal rate of COD was still higher than80%. Using CuO/AC prepared by co-precipitation method, the removal rate of COD increased with the increases of amount of the catalyst at first and then decreased. When the catalyst reused for10times, the removal rate of COD was still up to85%. The optimal conditions were catalyst addition of90g/L, H2O2addition of2500mg/L, reaction pressure of0.6Mpa and temperature of160℃.(3) Under the experimental conditions, inner electrolysis treatment of phenol wastewater was worse than the wet peroxide oxidation treatment significantly, the removal rate of COD was only between70%and80%. Only cooperating with wet peroxide oxidation method, the treated wastewater could be reached discharge standard. Furthermore, inner electrolysis method has obvious shortcomings such as the blockage of filler, replacement frequently of iron and maintenance difficulty.