| Al2(SO4)3, FeCl3, PAC and PAFC were used to coagulate the effluent of MSW incineration leachate after biochemical treatment, and mathematical models for COD removal were set up as well. The results show that COD removal rates are 20%, 17%, 30% and 40% respectively with addition of 500 mg·L-1 Al2(SO4)3, FeCl3, PAC and PAFC alone at pH 6. The <2 000 fraction contains mainly dissolved organics from the leachate after biochemical treatment. Moreover, according to the analysis of Zeta potential and transmission electron microscope (TEM), the main mechanisms of the leachate coagulation can be explained as electrical neutralization, netting and bridging. As a matter of fact, compared to inorganic coagulants, the poly coagulants show higher capacity on these three functions. |
