Study On The Treatment Of Xi’an Jiang Cungou Landfill Leachate By Physical-chemical Method

Landfill leachate is a kind of high concentration and difficult degraded organicwastewater. When China promulgated and implemented a new landfill leachateemissions standards in2008,many of the landfill leachate,s treatment facilities werenot up to the new demands and must be upgraded, the main problem is that landfillleachate contains a lot of degraded organic matters, and it is difficult to be handled bybiochemical menthod, this experiment uses the physical-chemical methods(coagulation, Fenton, iron-carbon–micro-electrolysis) as the pretreatment researchof Xi’an River Village ditch landfill leachate, in order to find an economic, efficientmenthod that can make the biochemical method is easier for landfill leachate.This experiment uses the physical-chemical methods (coagulation, Fenton, iron-carbon–micro-electrolysis) as the pretreatment research of the landfill leachate, firstwe use coagulation method and Fenton method as the pretreatment research of thelandfill leachate, analysis the dosage, reaction time, pH etc we can draw a conclusionthat:(1) use coagulation method as the pretreatment research of the landfill leachate,the chroma,s removal effect is not obvious, only up to50.2%, but the removal rate ofCOD can reach47.1%of the maximum, the optimal reaction parameters are that: thedosage of the PFS solution(the mass fraction is10%) is1.2g/L, stirring speed is350r/min, the pH is7, the reaction time is120min.(2) use Fenton method as thepretreatment research of the landfill leachate, the removal rate of COD and chromacan reach45.6%and93.8%separately, then the optimal reaction parameters arethat:the pH is3, the dosage of H2O2is6mL/L, n (H2O2)/n (Fe2+)is8:1and the reactiontime is90min.Secondly by comparing coagulation method and Fenton method in the aspects oftechnology and economy, we obtain that use the landfill leachate that be treated by thecoagulation method as the iron-carbon-micro electrolysis,s experiment water. Usethe iron-carbon-micro electrolysis as the pretreatment research of the landfillleachate, though select Iron filings, consider whether the aeration is needed, the massratio of Iron and carbon, how much the Aeration rate is and the pH etc, we obtain theoptimal reaction parameters are that；the mass ratio of Iron and carbon is4:1,the reaction time is120min,the aeration rate is40L/h and the pH is3,the removal rate ofCOD and chroma can reach60.3%and92.7%separately.Finally contrast the landfill leachate that be treated by iron-carbon-microelectrolysis with the initial landfill leachate, we can see the biodegradability wasincreased from0.18to0.45and reached the biochemical treatment requirements, theremoval rates of COD, BOD, SS, ammonia nitrogen and chroma were79%,54%,91%,51%,96.8%separately, it achieves the effect of pretreatment and illustrates thatusing the coagulation-iron-carbon-micro electrolytic method as the pretreatment ofthe leachate is feasible. In real life the technology of usingcoagulation-iron-carbon-micro electrolytic method as the pretreatment of wastewateris very mature and costs lesser,so using coagulation-iron-carbon-micro electrolyticmethod as the pretreatment of the leachate in order to improve the biodegradability isreasonable.