Experimental Study On Treatment Of Landfill Leachate With Fenton Method And A/Omethod

There are some characteristics existing on Landfill leachate, such as high content of organic compouds, most of which are refractory to biodegradation and complex organic of macromolecule, changeable water quality, high concentration of ammonia nitrogen and heavy metal, thereby if not treated properly, it will pollute the groundwater and its surrounding, also influence human daily life. And yet neither of the common biological and physical methods meets the technical treating requirements, accordingly studying on treating leachate is imperative and urgent.In this paper, Fenton method and A / O method were combined to treat landfill leachate. the Fenton reagent optimum experimental condition was determined for removing COD, NH₃-N in leachate, the toxicity to bacteria was reduced, the biodegradability of leachate was improved and the more suitable conditions for following A / O bio-treatment were createdThough orthogonal experiments and single factor analysis experiment, the Fenton reagent optimum experimental condition was determined for removing COD, NH₃-N in leachate. Taken the experimental efficiency and cost into consideration, the most suitable condition was defined and was that the initial pH = 5, FeSO₄·7H₂O dosage 0.03mol/L, reaction time 2h, nH₂O₂: nFe²⁺ = 1: 1.Mixed the simulated sewage and treated leachate by Fenton reagent or untreated, two new kinds of wastewater were procured. Put the two kind of wastewater into A / O reactor respectively, they were treated by the biochemical method, aquatic quality of COD and TP was measured. Contrasting the mixture of treated leachate and simulated sewage to mixture of leachate and simulated sewage, the COD and NH₃-N removal rate was improved evidently. It meant the biodegradability was increased. But only when the volume rations of the two kinds mixture were 1:50 and 1:25 can the COD concentration meetâ…¡-class criteria of urban wastewater treatment plant discharge standard (GB18918-2002), any increment proportion of leachate, even treated leachate, would lead it to fail to reach the criteria.Due to the high concentrations of ammonia nitrogen, in any proportion cases, effluent ammonia concentration could not reach GB18918-2002 urban sewage treatment plant ammonia discharge standards. It meant that complying with the discharge standard required the mixture ammonia concentration must be decreased, in other words landfill leachate shoud make up only a small section of the mixture.