Study On Improvement Of Biochemical Effluent Quality Of Landfill Leachate By Iron-carbon Micro-electrolysis

Due to its complex pollutant composition,Leachate has been a hot issue in the field of wastewater treatment for a long time.With the national attention on environmental protection,leachate emissions requirements are stricter,single biochemical process can not meet the requirements of emissions.The combining of biochemical and phys-chemical methods become the mainstream process of landfill leachate treatment.Leachate biochemical effluent is characterized by poor biochemical properties,low levels of pollutants but can not meet discharge standards.In this paper,the two-stage biochemical effluent of landfill leachate was treated with iron-carbon microelectrolysis technology.The single factor experiment and orthogonal experiment of beaker reaction was selected to optimize the parameter.Continuous flow experiment is used for optimize of experimental conditions.The improvement of water quality of biochemical effluent was systematically analyzed.Based on the combination of single factor experiment and orthogonal experiment,the optimum parameters of iron and carbon microelectrolysis were studied.The results showed that the different three kinds of materials have the same optimum experimental parameters were as follows: p H value 4,reaction time 90 min,Fe / C mass ratio 4: 1,iron and carbon dosage 10g/150 m L leachate.Under the optimum conditions,the effect of microelectrolysis on the anaerobic effluent and aerobic effluent of landfill leachate was compared.It was found that the COD removal efficiency of the two biochemical effluents was similar,and the biodegradability of the aerobic effluent was improved obviously.The three kinds of composite materials were filled in a small reactor,and the experiment was carried out under the conditions of p H value 4,reaction time 90 min,Fe/ C mass ratio 4: 1,iron carbon dosage 10g/150 m L leachate.The results showed that the influent concentration effect had little effect on the treatment effect of the three kinds of fillers,and the removal effect was the highest at medium concentration.In the aeration conditions,the micro-electrolysis treatment effect is obvious.With some H2O2's introducing,the COD removal of micro-electrolysis can effectively improve,polymerization of iron carbon ball,activated carbon iron scrap,coke iron scrap were increased by 15%,20% and 20%,respectively.Under the multi-stage microelectrolysis treatment,the higher the series,the greater the COD removal rate.But with the growth of the series,COD grade growth rate decreased.Compared the effect of the reactor treatment with three materials as the filler and the amount of Fe2+in the microelectrolyzed effluent and the total amount of iron after the precipitation in the continuous operation for 5 days.The results show that the Polymerized iron ball ismore appropriate.The system performance was investigated under the best condition.For 30 days,COD removal rate remained at around 25%,and the p H of the effluent was maintained at 6-7.5.The total amount of biodegradable organic matter in the landfill leachate was decreased from the point of view of molecular structure and organic composition,and the total amount of biodegradable organic matter in the landfill leachate was decreased by the analysis of the organic matter in the effluent and the organic matter.Material content decreased,humic acid corrosion reduced.The results showed that the COD and ammonia nitrogen removal rates of the two groups were higher than those of the microelectrolysis effluent group,and the biomass of the micro-electrolysis effluent group was much higher than that of the micro-electrolysis inffluent.From these two angles,it was confirmed that iron and carbon microelectrolysis had an improved effect on the biochemical effluent quality of landfill leachate.