The Pretreatment Of Landfill Leachate By Micro-electrolysis-Photo Fenton Reagent

Landfill leachate means the sewage filtered out from the garbage during its stacking and landfill through fermentation, the washing of rainwater or the soaking of surface water and groundwater.Characterized by a high concentration of organic subtances and metals,a wide range of water qualities,a high percentage of ammonia nitrogen and the lack of proportion of nutrient elements,it is a kind of organic waste water extremely difficult to degrade and be discharged after general biological treatment while meeting the relevant standards.This paper reseaches into the pretreatment of landfill leachate by the Micro-electrolysis—Photo Fenton reagent and mainly focuses on the influence of various factors of reaction on the treatment effect as well as the best conditions for reaction.During the part of Micro-electrolysis treatment,the removal rate of COD increases with the rise of dosing quantity of iron fillings with the speed high in the early stage and low later.The removal rate approaches stable with the rise of dosing quantity of coke and increases quickly at first then drops with the rise of PH .The rate also grows as the time of reaction lengthens,fast at first and slower later.Under the best reaction conditions fixed by the experiments,the removal rate of COD in the raw landfill leachate is 34.06%.The COD in the effluent is about 2100mg/L and the BOD/COD value rises to 0.18 while the biodegradibility is enhanced.During the part of Fenton treatment,the removal rate of COD increases rapidly before drops gradually after the peak with the growth of dosing quantity of ferrous sulphate.The rate rises rapidly at first and then drops slowly with the increase of dosing quantity of hydrogen peroxide and experience the same process with the growth of PH while it grows quickly at first and then slower as the time of reaction lengthens. Under the best reaction conditions fixed by the experiments, the removal rate of COD in the effluent after Micro-electrolysis treatment is around 75%.The COD in the final effluent is about 550mg/L and the BOD/COD value rises to 0.34.The process of Micro-electrolysis—Photo Fenton reagent is briefly described as follows: Under the best conditions of each processing stages,the removal rate of COD reaches around 83% and the COD in the effluent is about 550mg/L.The BOD/COD value rises to 0.34 while the effluent is very suitable for follow-up treatment.