Advanced Treatment Of Landfill Leachate By Integrated Process Of Catalytic Micro-electrolysis And BAF

Lots of leachate would be inevitably generated in the process of MSW (Municipal solid waste) treatment through present waste treatment facilities, such as landfill plants, incineration plants, waste transfer station, dumping sites and refuse composting fields etc. This kind of the leachate has strong pollution characteristics,1ton of the leachate is equivalent to100tons of municipal wastewater pollutant concentrations, so if this by-product can not be effectively treated, then landfill plants, as the environmental protection facilities, will be directly changed into pollution resource. It is bound to cause secondary pollution to the environment. There is not a suitable treatment process at present in China because of the complexity and variability of the quality and quantity of the leachate wastewater. Therefore, at present it is imperative to find a leachate treatment process which is suitable to our national special situation and with high efficiency and low consumption.This article is a research of advanced treatment method to the leachate applying catalytic micro-electrolysis and BAF combined technology. By the static and dynamic experiment of common micro-electrolysis process, catalytic micro-electrolysis process and BAF technology, research for the controlling parameters of these processes, and explore the effect of advanced treatment for these technologies to the leachate. The catalyzed micro-electrolysis and BAF combined technology is not only suitable for the advanced treatment of the leachate, but also suitable for the treatment of the industrial wastewater with high concentration, low bio-degradability, toxic and hazardous compounds. The overall experimental work in this article is divided into the following three parts:The first part:research for the advanced treatment of common micro-electrolysis process to the leachate. By self-made static testing device of common micro-electrolysis, a group of static experiments were designed and fulfilled based on the four factors:volume ratio of iron slag and coke, optimum pH value setting under the acid and alkaline conditions, and optimum reaction period. Via analysis of the experiment results, it’s confirmed that the best optimal controlling parameters of this process are shown:optimal volume ratio of iron slag and coke is1:3, optimum pH value under the acid condition is3.0, optimum pH value under the alkaline condition is7.5, optimum reaction period of the micro-electrolysis is1.5h,optimum depositing period after regulating the wastewater into the alkaline condition is2.Oh.The second part:research for the advanced treatment of catalytic micro-electrolysis process to the leachate. By the common micro-electrolysis process, the removal rate of COD and chroma in the leathate can reach above63%and90%respectively. In order to further improve treatment effect of the common micro-electrolysis process, in this experiment powerful oxidant H2O2was added into the liquid which had been treated by the common micro-electrolysis process. A group of static experiments were designed and fulfilled based on weight ratio of H2O2and COD and the reaction period of catalytic micro-electrolysis process. Via analysis of the experiment results, it’s confirmed that the best optimal controlling parameters of this process are shown:optimal weight ratio of H2O2and COD is1.5:1, the optimum reaction period after adding powerful oxidant H2O2is1.5h.The third part:research for the advanced treatment of catalytic micro-electrolysis and BAF process to the leachate via dynamic experiment. According to the best optimum controlling parameters obtained from the static experiment, utilizing dynamic experiment devices such as self-made acid and alkaline blender, reactor of micro-electrolysis, oxidant mixer, sedimentation tank No.1and2. and BAF reacting biological pool etc. one-month dynamic experiment commissioning and operation has executed in line with dynamic experiment process. Via analysis of the experiment results, the catalytic electrolysis process can improve the biodegradability of the leachate, and create a good condition for the follow-up biochemical treatment. The leachate is firstly treated by the catalyzed micro-electrolysis process, treated by BAF biological process then, water quality of the leachate can satisfy the national emission standard stipulated.