Deep Research On The Tail Water Of Leachate From Jiang Cungou MSW Landfill

MSW（municipal solid waste）landfill will generate secondary pollution in the process ofoperation, the main secondary pollutant is leachate. Leachate is a high concentration organicwaste water, it has specialities of intricate components, high concentration of contaminations,large variety of water components and quantity. Due to the way of MSW landfill, leachatetreatment method and treatment equipment, the effluent is very difficult to reach therequirements of 《The pollution control standard of municipal solid waste landfill》（GB16887-2008）.In general, the tail water is the effluent of the leachate after biochemical treatment, it isof poor biochemical purification ability and often need to do further processing by using themethod of physical and chemical. In this paper, the tail water from MSW landfill of JiangCungou XI’AN was research object. I will put forward several physico-chemical combinationtreatment process, to explore a best combination process.This paper designed the five test: Dilution and alkali pretreatment, activated carbonadsorption, Fenton reaction, activated carbon-Fenton reaction and activated zeoliteadsorption. Through the analysis of pH, adding quantity, reaction time and so on, to explorethe optimum process conditions of reaction.The conclusion could be obtained as follows:1、The optimum process conditions of dilution and alkali pretreatment: pH=12; Afterpretreatment, The content of TP was reduced by96.1%, The content of the heavy metal Hgwas reduced by86.51%, the two indexes have meet the requirements o《fThe pollution controlstandard of municipal solid waste landfill》（GB16887-2008）; And COD and ammonianitrogen in leachate are reduced by21.1%and18.0%, respectively, has yet to reach dischargestandards.2、The optimum process conditions of activated carbon adsorption: initial pH=2³, theamount of active additive is20g/L, the reaction time is90min; After the pretreatment andactivated carbon adsorption, the removal rate of COD and ammonia nitrogen are63.5%and63.5%.3、The optimum process conditions of Fenton reaction: the initial pH=3, the amount ofH₂O₂is2.5g/L, the dosing ratio of H₂O₂and Fe²⁺is5:1, the reaction time is2hour; Afterthe pretreatment and Fenton reaction, the removal rate of COD and ammonia nitrogen are 73.5%and27.3%.4、The optimal dosing methods of activated carbon-Fenton reaction: adding theactivated carbon first, keep reaction30min, then add in Fenton reagent, and continue reaction2h;The optimum process conditions: initial pH=3, the amount of active additive is30g/L,the amount of H₂O₂is2g/L, the dosing ratio of H₂O₂and Fe²⁺is5:1, the total reaction timeis2.5hour; After the pretreatment and activated carbon-Fenton reaction, the removal rate ofCOD and ammonia nitrogen are91.9%and55.4%, respectively.5、The optimum process conditions of activated zeolite adsorption: initial pH=7, theamount of activation zeolite is25g/L, the reaction time for is30min; After the pretreatment-（activated carbon-Fenton reaction）-activated zeolite adsorption, Ammonia nitrogen removalrate has reached88.5%.Experimental studies show that after the test of pretreatment-（activated carbon-Fentonreaction）-activated zeolite adsorption, the contents of COD, ammonia nitrogen, TP and heavymetals in the tail water are basically can meet the the requirements of《The pollution controlstandard of municipal solid waste landfill》（GB16887-2008）.