Advanced Treatment Of Coal Chemical Wastewater By Microwave-enhanced Catalytic Wet Peroxide Oxidation

Coal chemical wastewater is a typical industrial wastewater containing refractory organic pollutants with high concentration and high chroma, its composition is very complex, after the secondary biological treatment the standard is still hard to meet, so it still needs to be deep treated. Thus, seeking an efficient and economical depth method has become a hot research topic.Wet peroxide oxidation as a kind of advanced oxidation technology, due to the fast oxidation speed, high efficiency, simple process, has a good treatment effect on the pretreatment of high concentrations of refractory toxic industrial wastewater and the treatment of organic wastewater. Meanwhile, in combination with a heterogeneous catalyst solves the problem of the catalyst difficult to recover, and there is no secondary pollution, which is expected to become an effective method for treating refractory organic wastewater.In this paper, a supported nickel-copper oxide catalyst was prepared with γ-Al2O3/Ti O2 as the carrier by impregnation method, and the preparation conditions were optimized. Then the catalysts were characterized by SEM, XRD, BET and other means. Quinoline wastewater was used to examine the efficiency of microwave-enhanced catalytic wet peroxide oxidation system. The degree of different factors were compared. Finally, the continuous flow depth treatment of the coal chemical wastewater by microwave-enhanced catalytic wet peroxide oxidation was studied, the water quality was analysised before and after handling ingredients, and stability of the catalyst continuous flow operation were discussed.Cu-Ni/γ-Al2O3/Ti O2 catalyst was prepared by impregnation method and the different preparation conditions were investigated, the optimal preparation condition of catalyst is determined as follows: impregnation concentration 1.5 mol/L, the active component ratio of Cu:Ni = 5:1, calcination temperature 300 ℃, calcination time 5 h. The catalysts characterization results showed that the main active group of catalysts were Cu O and Ni O. The catalyst surface area, total pore volume and average pore diameter were all reduced compared with carrier.Through the study of the degradation of quinoline which is a typical contaminants in coal chemical wastewater, microwave power, H₂O₂ dosage, reaction temperature and the initial p H value have great effects on the treatment of the reaction system, the impact of the most significant factors in which microwave power and H₂O₂ dosage.Microwave-enhanced catalytic wet peroxide oxidation was used to the treatment of coal chemical biological secondary effluent, in continuous operation, the effects of microwave power, H₂O₂ dosage and HRT on the system was studied, the optimum process conditions for microwave power of 500 W, H₂O₂ dosage of 0.094 mol/L, HRT taken 18 min, COD value of waste water decreased from 114.8 m /L to 56.8 mg/L, the effluent can be achieved of "the integrated wastewater discharge standard " a B standard. Compared the water quality before and after handling ingredients, advanced treatment of wastewater containing heterocyclic compounds substantially effectively removed.