Advanced Treatment Of Oil Wasterwater By Heterogeneous Catalytic Ozonation Oxidation

The staggering advancement of economic and increasingly energy demand were attended by severe pollution of water shortage and ecosystem by oil refining wastewater. Non-biodegradable oil refining wastewater was unable to meet recycling wastewater standard utilized biological treatment. In present day, reuse rate of oil refining sewage was below35%. Therefore, wastewater reuse not only responded to the call of national energy conservation but also brought about significant benefits upon economic and environmental as well.The paper was focused on effluent of biological treatment as the study objects from a south refiner. It was studied from lab and advanced levels to continuously optimize parameters using heterogeneous catalytic ozonation process. From the results of pilot of the impact load and continuous running experiments, it verified the process characterized of good resistance and stability to impact load and meet the requirements of corporate wastewater reuse standard. At the same time, the mechanism of heterogeneous catalytic ozonation was simply discussesed.The Mn–Cu oxide (Mn–Cu–O) catalysts made by impregnation method were measured through BET、XRD、SEM、EDS、FT-IR、 AAS which proved the active components of catalyst were CuO and MnO2respectively. The heterogeneous catalytic ozonation of refinery wastewater in the presence of Mn-Cu oxide (Mn-Cu-O) catalysts was investigated under different operating parameters by COD and ammonia nitrogen degradation. Ozone dose:50.0mg/L、catalyst dose:3.0g/L、 initial pH=6.8、 T=17℃were the optimum values to meet the standard. The kinetics of the COD removal was corresponding to pseudo-first-order rate equation. Fluorescence spectroscopy and GC-MS were implemented to discuss the mechanism of heterogeneous catalytic ozonation. Finally, the possible mechanism of the catalytic ozonation was proposed.The influence of NaH2PO4showed that the surface hydroxyl groups played an important role during the catalytic ozonation and the hydroxyl surface groups were the active sites of the Mn–Cu–O catalyst. From results,we proved that it could oxidize complex organic compounds into simple organic compounds, especially organic nitrogen.In the advanced level, the average effluent of refinery wastewater was COD <50mg/L、 ammonia nitrogen <6mg/L, which meet the standard under the retention time15min、ozone dosage of50mg/L、 pH=6.8. Meanwhile, tons of water treatment cost were￥1.216, which has obvious economic advantage.In this paper, the heterogeneous catalytic ozonation process was a new method for refining wastewater advanced treatment. And it was characterized with high efficiency and low cost, which was a promising technology.