Removal Of Arsenic And Organic Pollutants From High Salt Wastewater Using Fenton Oxidation And Precipitation With Lime And Ferric Salt

Smelting wastewater with high salt concentration mainly comes from metallurgy and chemical industry,with high salt concentration,high arsenic content, high concentration of organic compounds. It is difficult to achieve good treatment effect by coagulation and biological process. At present, the main processing method is Fenton oxidation, ozone oxidation and photocatalytic oxidation; The Fenton oxidation process is used widely in the actual processing; For wastewater containing large amounts of arsenic, the main processing methods are chemical precipitation, adsorption, membrane method, electrodialysis method, electric coagulation, ion exchange method, ferrite method, microbial reforming process and active sludge method. Chemical precipitation has short reaction time and good treatment effect, precipitation by both lime and ferric salt is commonly used in industry. Although the high salt organic wastewater and the wastewater containing arsenic has made certain research progress, however, the comprehensive treatment for Smelting wastewater with high salt concentration is not deeply study.Therefore, the comprehensive treatment of smelting wastewater with high salt concentration has the very good practical significance. In this study, Fenton oxidation and precipitation by both lime and ferric salt were used to treat smelting wastewater with high salt concentration.In this study, first of all, using the orthogonal experiment to determine initial operating conditions of Fenton oxidation, then, using the single factor analysis to research the main influence factors of Fenton oxidation test and study the impact to CODCr removal of wastewater, the results showed that the optimal Fenton oxidation operating conditions for the treat of the wastewater are determined as follows:a rapid increase in CODCr removal rate was observed and reached85.5%when FeSO4·7H2O/H2O2(m/m)=1.2:1, H2O2dosage of12ml/L, pH=4and the reaction temperature is70℃after30min reaction. If hydrogen peroxide been putted into by three times, every10min dosing time, CODCr removal rate reached87.1%, increased by1.6%, it can be seen the method of batch adding hydrogen peroxide can further improve the CODCr removal rate.After Fenton oxidation treatment, then precipitation by both lime and ferric salt, in view of make further treatment to the wastewater As removal rate. The subject of precipitation by both lime and ferric salt is single factor test method, test different CaO dosage, reaction time on the removal of As, the results indicated that:the removal rate of As reached99.4%at CaO dosage of4.5g/L and reaction time of3.0h.Researeh for this paper, laid a theoretical foundation for the practical application and provided an experimental basis, in Fenton oxidation and precipitation by both lime and ferric salt to treat smelting wastewater with high salt concentration.