| In recent years,waste incineration power plant technology has been widely used to treat municipal solid waste.In this way,solid waste can be better resourced,in line with China's national conditions,and it is an industry that is encouraged to develop,but the Same as sanitary landfill,Domestic waste incineration power generation is also facing the problem of difficult to treat leachate.RO concentrated water is the residual concentrate which is intercepted by reverse osmosis membrane after the biodegradation of landfill leachate.Which is brownish black,and the organic matter concentration,biological oxygen demand?BOD?and chemical oxygen demand?COD?are high,the content of toxic and hazardous substances are higher,it is not allowed to be discharged,and also not allowed to enter the municipal sewage treatment system.Therefore,once the landfill leachate RO concentrated water is improperly disposed,it is easy to cause serious secondary pollution,and its effective treatment has become the focus of attention.This topic combines the existing process of waste incineration power plant,firstly adopts Flocculation-Fenton composite treatment of RO concentrated water,and then uses the RO concentrated water to prepare lime slurry spray to absorb H2S and SO2 generated by waste incineration process,achieve the purpose of harmless RO water in leachate from waste incineration power plant,and further reduce the emission of high concentration pollutants in the leachate of the waste incineration power plant.The results of RO water concentration of landfill leachate are as follows:COD is4515mg/L,BOD5 is 1918.5mg/L,NH3-N is 2290mg/L,and the color is 420 times,the content of inorganic pollutants in the leachate system is relatively high,the degree of mineralization is 60662mg/L,there are fewer types of inorganic non-metal ions,more types of metal ions,and more types of organic substances.Firstly,the water sample was pre-treated by flocculation method,four kinds of flocculants such as PFS,FeCl3,PAS and Al2?SO4?3 were investigated to treat the leachate RO concentrated water system.The flocculation effect finally selects PFS as the best flocculant.Under the optimal conditions of pH is 6,PFS addition is 0.4g/L,stirring rate is150r/min,the results show:COD is 1498.98mg/L,the removal rate is 66.8%;NH3-N is1641.93 mg/L,the removal rate is 28.3%,the chromaticity is 88 times,and the removal rate is 79%.The PFS-pretreated water sample was further treated by Fenton oxidation method.The best conditions are:the dosage of Fe2+is 25mmol/L,n?H2O2?/n(Fe2+)is 6:1,pH is 3,and reaction time is 60min.Under the conditional treatment,the water samples after the final treatment showed:COD is 376.5 mg/L,NH3-N is 114.5 mg/L,chroma is 16 times,COD removal rate is 92.1%,and NH3-N removal rate is 94.9%.The chroma removal rate is96%.The RO concentrated water treated by the PFS-Fenton composite process is used to prepare a lime slurry,which is used as a desulfurizing agent in the wet desulfurization process,thereby utilizing this part of the RO concentrated water.However,the RO concentrated water with high concentration of slaked lime is easy to scale.At present,there is still no scale inhibitor that can effectively solve this problem.Therefore,it is necessary to develop a new scale inhibitor to solve the scaling problem of RO concentrated water reuse system.This topic is aimed at the scaling problem of the above RO concentrated water reuse system,based on the background and experience of the current research.A scale inhibitor capable of better scale inhibition efficiency in RO concentrated water environment is synthesized,and the synthesis conditions are optimized and its mechanism of action is discussed.By using a free radical aqueous solution polymerization method,maleic anhydride,acrylic acid and acrylamide are used as raw materials,and 4%ammonium persulfate is used as an initiator.The reaction was carried out at a pH of 5-6,and the temperature is 80?for 3.5 h.Based on the above various process conditions,a process study on the comprehensive utilization of RO concentrated water in landfill incineration plant leachate is carried out.The feasibility of the process is verified by adjusting the process parameters of each part and carrying out simple economic analysis. |
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