Research On Degradation Characteristic Of Sanitary Landfill Leachate By Adsorbing-composting Treatment

Since the1980s, China started to use sanitary landfill to dispose garbage, until now thiskind of technique is still widely used. Although the sanitary landfill numerous technicaladvantages as a garbage disposal, landfill leachate brings serious environmental hazards.Landfill leachate changes a lot in quality and quantity, containing high COD and ammonia, soit is hard to purify and recycle. In order to achieve the coordination of economic andenvironmental benefits, leachate reduction, harmlessness and resources, this paper usesnon-metallic inorganic materials adsorption-composting treatment to deal with landfillleachate.This experiment uses diatomite and bentonite as adsorbent for adsorption–composting,studying material pollutants degradation characteristics (in the summer phase) and theaffects of environmental temperature on the composting progress(in the winter phase),conclusions are as following:(1) By adsorption of the two non-metallic mineral adsorbent-composting experiment,in the previous28days, degradation meets the zero-order reaction kinetics, the diatomitecomposting meets the zero-order reaction kinetics equation: s_t=-0.3295t+22.552，R~2=0.9866， bentonite composting meets the zero-order reaction kinetics equation:s_t=-0.2239t+37.152，R+=0.9861.(2) after a reaction period of28days, the nitrogen transformation basically becomesstabilized, according to the content of total nitrogen, ammonia nitrogen and nitrate analysisresults, the total quantity of latter two elements equals the former one, we can determinethat when compost system stabled, the nitrogen has been converted into small moleculesbasically, which can be absorbed by plants, and composting is successful.(3) According to 《Compost Quality Standard》，bentonite compost almost meet thestandard except the TN is a little lower, but with bentonite using in sandland control thecompost product can be used to control and fertilize sandland. Due to the nature o f diatomite,diatomite adsorption compost pH is always below5, which cannot meet the standard, with thecharacteristic of low pH, it can be used to control saline-alkali soil.(4) In Summer organic pollutants can completely degradated; it differs in winter, six daysafter the experiment the degradation takes no more change. It shows to us that temperature isa fundamental factor to the small-scale composting.