Removal of organics from Huangpu River water by different coagulants

摘要

Jar-test experiments were performed to investigate the effectiveness of enhanced coagulation in organic removal from Huangpu river water.The results show that.For Huangpu river water,the suitable type of coagulant is ferrous chloride;the optimal pH for the removal of organics is 5.5,and the dose of FeCl3 is 30mg ? L-1,at which the removal effect of the DOC ,UV254 are 42% ,56% and 60% respectively;As a matter of fact,ferric chloride and aluminum sulfate have similar removal effect to organics at ambient pH,while can gain higher efficiency at pH 5.5,(higher 12% DOC and 20% UV254),we can conclude that the main mechanism for coagulation to remove organics is the reactions between coagulants hydrolysis species and organics;Seen from the result of U V scan,the enhanced coagulation remove mainly the organics which can be adsorbed by the UV whose wavelength higher than 250 nm,which is mainly aromatic compounds and polynuclear aromatic hydrocarbons;Enhanced coagulation can reduce the chlorine demand of the raw water effectively,for it can remove the organics which can adsorbed by the UV at 272nm.