Study On The Reduction And Resource Of Absorption Solution In Simultaneous Desulfurization And Denitration By ClO₂

China is a developing country with coal as the main energy source,coal consumption has always maintained a high level,accounting for 64%of China's energy structure and more than 50%of world consumption.The Emission standard of air pollutants for coal--burning oil-burnig gas-fired boilers proposed nitrogen oxide and mercury emission control standards for the first time,but China's small and medium sized industrial boilers desulfurization is not universal and do not remove nitro and mercury at present.Some mature technology for thermal power plant boiler desulfurization and denitrification but not suitable for small and medium sized industrial boilers.After years of experimental study,ClO2 oxidation method is most promising to solve thesmall and medium sized industrial boiler desulfurization and denitrification at the same time,In order to solve the problem of the simultaneous desulfurization and denitrification by using ClO2,which is the disposal of waste liquid.And to explore the feasibility of the reduction and resource of waste liquid.Under the optimal parameters,using laboratory-made sieve plate spray tower for testing the effect of simultaneous desulfurization and denitrification of ClO2.The results showed that the removal rate of SO2 was close to 100%and the removal rate of NOx reached 97.48%.Recycling the absorption of liquid five times with the concentration of absorbed liquid is 200mg/L every time.The ion concentration of the absorbed liquid was measured by five-step iodometric method and ion chromatography at before and after the reaction,which can obtaine the linear fitting formula and the ratio of Cl-,SO42-and NO3-:Cl-:SO42-:NO3-=2.412:1.81:1.Based on the proportional relationship,Hydrochloric acid,nitric acid and sulfuric acid were added to the absorption solution according to the concentration gradient to simulate the absorbing liquid after multiple times repeated use,and doing the desulfurization and denitrification test.The results show that the increase of acid concentration in the absorption solution will not affect the desulfurization and denitrification effect.The waste liquid of simultaneous desulfurization and denitrification by using ClO2 can be achieved reduction.In this paper,the feasibility of preparing poly iron flocculant by ClO2 simultaneous desulfurization and denitrification absorption waste was also explored.The liquid polyferric flocculant is prepared by adding ferrous sulfate and oxidizing agent sodium chlorate in the acid waste by stirring and curing.The main technical indexes of the 1%solution pH,the salt base,the total iron content and the color of the solution were calculated and calculated,which fully comply with the preparation of polyferric sulfate technical requirements in the water treatment agent polymerization iron sulfate.By comparing the flocculation effect of polymerized ferric sulfate,the results show that,When the dosage of polymerized ferric sulfate reached 100mg/L,the decolorization effect was the best which is reaching 60.96%,When the dosage of self-prepared coagulant is 93 mg/L,the flocculation effect is the best and the chroma removal rate is 75.69%.When the dosage of ppolymerized ferric sulfate is 400mg/L,the CODcr best removal rate is only 25.61%,but the optimum dosage of self-prepared coagulant is relatively small,which is 93mg/L,and the CODCr best removal rate is 37.2%.The self-prepared coagulant can also achieve the removal efficiency of chroma and CODcr as polymerized ferric sulfate products.Finally,scanning the UV spectra of self-prepared coagulant and polymerized ferric sulfate,The results show that the iron ion morphology in the self-prepared coagulant solution is the same as that of the polymerized ferric sulfate products.In this study,we found a reasonable approach to the comprehensive utilization of desulphurization and denitrification waste liquid.ClO2 simultaneous desulfurization and denitrification by recycling absorben liquid to achieve the reduction,it also use the acid waste to prepare coagulant to achieve resource.With this method both to solve the waste liquid problem,to avoid secondary pollution,but also produce some economic benefits.To solve the last bottleneck problem of the simultaneous desulfurization and denitrification in the small and medium sized industrial boilers,so that the process closer to industrial applications.