Research On Treatment Of Landfill Leachate By Three-Dimensional Electrode Combined With Electro-assisted Biological Technology

Landfill leachate is an environmental pollutant produced by sanitary landfill,with complex components and strong environmental destructiveness.Nowadays,the treatment of leachate is faced with many challenges,such as the increasing difficulty of wastewater treatment.This makes the innovation of landfill leachate treatment technology inevitable and necessary.Therefore,this paper took effluent of the second biological treatment unit from a leachate treatment plant in Nanchang as the research object.The feasibility of advanced treatment of leachate with three-dimensional electrode of volcanic stone combined with electro-assisted biological technology was analyzed in this paper.Firstly,through single factor experiments,it was found that the three-dimensional electrode of volcanic stone obtained the best treatment effect under the conditions of 10V,4000mg/L Cl-,plate spacing being 6cm and neutral water quality.The removel rates of COD,NH3-N and TP were 60.92%,23.72%and 44.99%.Adding Cl-can promote the degradation of NH3-N.Then,through the optimization of the response surface design,regression equation was obtained.The difference between predicted values of the aquation and actual values within the experimental range was small,indicating that the equation had practical significance.According to the response surface regression equation,the best experimental conditions were as follow:4526.56 mg/L Cl-,11.56V and plate spacing being 4.83cm.After verification,the actual experimental results were close to the fitting results.Under this experimental condition,the removal rates of COD and NH3-N were 62.5%and 29.3%.The three-dimensional electrode system produces ·OH and other active substances,which can destroy refractory organics such as humus and conjugated unsaturated group.The three-dimensional electrode can effectively reduce chromaticity and improve biodegradability.Finally,the electro-enhanced anoxia/aerobic was used to treat the effluent of three-dimensional electrode unit.The application of electricity and additional carbon source can promote microbial activity to degrade pollutants.Under the conditions that the hydraulic residence time is 24h with 1.5V voltage and additional carbon source,it can improve purification effect.After treatment,the concentration of COD and NH3-N were 143-180mg/L and 4.5-8.4mg/L,respectively.