Study On The Adsorption Of Heavy Metal From Urban Landfill Leachate By Modified Bentonite

Landfill leachate is a kind of wastewater with complicated components: it contains avariety of toxic and harmful heavy metal. The heavy metal ions in municipal solid waste willcause serious harm to the survival of plants and animals, ecological environment and humanhealth. Therefore, we must remove the heavy metals in landfill leachate, in order to avoidavoid it causing harm to the survival of plants and animals, the ecological environment andhuman health.The layered structure of bentonite is unique and it can pwertful adsorb organic pollutantsand heavy metal ions. The adsorption of bentonite can greatly enhance after organic modified,which can effectively remove inorganic pollutants and organic pollutantsr. This experimentproduce the mass fraction of3%,5%and7%CTMAB modified bentonite. This experimentthrough the instance the heavy metal content and features of jiang village landfill leachate,determine the Cr, Ni as the main remova object, adopt different mass concentration CTMABmodified bentonite and bentonite processing jiang village landfill leachate, through theorthogonal experiment, conclusions are as following:（1）The monitoring results of jiang village landfill leachate show that the heavy metalsin landfill leachate are Cr, Ni, Cu, Cd and Pb, of which Cr is over the living garbage landfillpollution control standard (GB16889-2008).（2）The removal rate of Cr, Ni by bentonite are63.2%,65.6%, The removal rate of Cr,Ni by modified bentonite are93.6%,95.2%, the removal rate of Cr, Ni increased by30.4%and29.6%after modified.（3）The optimal conditions for the removal of Cr and Ni in landfill leachate is: theadsorbent is the mass fraction of7%CTMAB modified bentonite, the best adsorbent dosageis m(Cr/Ni)/m(bentonite)is0.134/0.143mg/g, pH value is three, the adsorption time is45minutes, the adsorption temperature is25℃. Under the optimum experiment conditions, theremoval rate of chromium is93.6%, the removal rate of nickel is95.2%.（4）The removal rate of chromium and nickel in landfill leachate by modified bentoniteis increased with the increase of the concentration of CTMAB, increased with the increase ofthe dosage of bentonite, first increases then decreases with the pH value increases increasedwith the extend of the adsorption time, first decreases then increases with temperature rise.（5）Modified bentonite can effectively remove heavy metals in landfill leachate, consider the treatment effect and the economy, modified bentonite can preprocess jiangvillage landfill leachate, providing guarantee conditions for the follow-up biologicaltreatment.