Research On The Recirculation Technology Of Leachate From Municipal Refuse Landfill

At present,almost 90%of the municipal refuse in our country was treated with the technology of landfill.The principal environmental problem of landfill is leachate of which the water quality is complex,whth high CODer and high NH₃-N concentration as well as high heavy metal ion concentration.The soil and groundwater will be polluted if the leachate entering into environment.So seeking a economical leachate treatment process adapted to China is an impendent problem to promote the development of landfill technology.Considering the reality of our country,recirculation as an effective treatment technology of leachate has a great prospect for development.Under the completely natural condition,the paper adopted the pattern which landfilling,colleeted the leachate and studied the leachate recireulation method processing effect.The experiment was mainly absolutely reeirculation and tried to study the effect of removal CODcr,NH₃-N,the impact factor of leachate reeirculation and the removal mechanism of NH₃-N,the results showed that:.(1) In temperature range which carries on in the experiment,landfill body average subsidence speed(y)is linear correlation to the total time of landfill body(x).The relationship before 12 days,No 1(not reeirculation) is:y=-0.0875x+1.648 No 4(recirculation) is:y=-0.0830x+1.790The maximum average sendimentation rate of No4 was 0.13cm/d than No1.Owing to recireulation,time of the anaerobic metabolism phase can be reduced,and also decomposition of the organic substance can be accelerated.Thus,finally stabilization of the refuse was speed up.(2) Temperature is an important factor in dealing with leachate recirculation,with the temperature rising,the removal is declining clearly.(3) pH is an important factor in dealing with NH₃-N of leachate reeirculation,alkaleseent environment is appropriate to nitrifying bacteria and denitrifying bacteria growth and is conducive to the removal of NH₃-N.(4) In the extension of experiment,recirculation has an removal rate for CODcr,NH₃-N, the,best rate of removal in summer is 16.48%and 21.06%,in autumn is 12.67%and 9.62%.Considering the removal rate and the stability of remove,the aerobic recirculation entirely has better effect for the removal of CODcr,NH₃-N than anaerobic treatment。...