Study On The Effect Of Multiphase Fenton Catalytic Oxidation Of Refractory Organic Wastewater

With the development of the economy and the advancement of industrialization,more and more new substances such as medicines,pesticides and endocrine disruptors have been invented.These substances are continuously accumulated and enriched in the water body,causing serious pollution to the water environment,and ultimately endangering human life and health through the action of the biological chain.Studies have shown that these pollutants and their metabolites are not only toxic but are mostly persistent,intractable and difficult to biodegrade.The removal by conventional biochemical treatment methods is not ideal.Hydroxyl radicals produced by the multiphase Fenton catalytic oxidation system can selectively degrade pollutants,and the treatment effect on refractory organics is obvious.Compared with the traditional homogeneous Fenton system,the multi-phase Fenton system has the advantages of wide pH response range,recyclability,easy solid-liquid separation,etc.,and thus has become a research hotspot for the treatment of refractory organic wastewater.In this paper,Cu/Al-silica was synthesized by hydrothermal method as a catalyst to construct a multi-phase Fenton catalytic oxidation system.The optimum reaction conditions of the system were investigated with the decolorization rate of Rhodamine B.The target was contaminated with chlorobenzene.The effects of multiphase Fenton system removal and the stability of the reaction system were studied.The effects of multiphase Fenton system and traditional Fenton and Fenton-based systems on the treatment of laboratory refractory organic wastewater were investigated.Catalytic oxidation performance of the system.The experimental results show that the two multiphase Fenton systems with Cu-silica and Cu/Al-silica as catalysts can treat the refractory organic wastewater under neutral conditions,and the treatment effect is better than the traditional Fenton system.The optimal reaction conditions for the multi-phase Fenton catalytic oxidation system in the treatment of rhodamine B solution with a concentration of 100 mg/L are:pH value 5,reaction temperature 25 0C,catalyst dosage 4 g/L,hydrogen peroxide dosage 20 mmol/L.The system used for the treatment of refractory chlorobenzene solution,the COD removal rate reached 51.9%,and the biodegradability increased to 37.7%.The catalysts participating in the first reaction were subjected to repeated experiments after simple treatment.After repeated use for five times,the COD removal rate in the reaction system was still 47.2%,and the biodegradability of the wastewater was maintained above 33%.The amount of metal ion eluted from the reaction effluent is negligible compared to the amount of catalyst charged.The multi-phase Fenton system,the traditional Fenton system and the Fenton-like system are simultaneously treated in the laboratory under the optimal reaction conditions for the laboratory refractory organic wastewater.Comparing the treatment conditions and treatment effects of the three Fenton systems,it can be seen that the multiphase Fenton system exhibits stronger activity under neutral conditions,and the best effect is better than the other two reaction systems.The COD removal rate is 12.8%higher than the traditional Fenton,which is 35.2%higher than the Fenton method.The biochemical improvement effect is 12.5%higher than the traditional Fenton method,and the Fenton method is 50%higher.The water quality meets the requirements of biochemical treatment;the removal of chromaticity is similar to that of traditional Fenton,but it is 50%higher than the Fenton-like method.