Study on coagulation property of metal-polysilicate coagulants in low turbidity water treatment  

作　　者：杨海燕 崔福义 赵庆良 马超 

机构地区：[1]SchoolofMunicipal＆EnvironmentEngineering,HarbinInstituteofTechnology,Harbin150090,China

出　　处：《Journal of Zhejiang University Science》2004年第6期721-726,共6页浙江大学学报（自然科学英文版）

基　　金：Project (No. E9825) supported by the Natural Science Foundation of Heilongjiang Province,China

摘　　要：In order to remove the low turbidity present in surface water, a novel metal-polysilicate coagulant was used to treat the raw water taken from Tanjiang River in Guangdong Province. This study on the effects of Al/Fe molar ratio on the performance of a complex compound formed by polysilicic acid, aluminium and ferric salt (PAFS) showed that PAFS with Al/Fe ratio of 10:3 seemed to have the best coagulation performance in removing turbidity and color. Experimental results showed that under the conditions of polymerization time of 15 d, sedimentation time of 12 min, and pH of 6?8, PAFS with Al/Fe molar ratio of 10:3 had the best coagulation efficiency and lowest residual Al concentration. The turbid- ity decreased from 23.8 NTU to 3.23 NTU and the residual Al concentration was only 0.165 mg/L in the product water. It could be speculated that colloidal impurities and particulate Al were removed by adsorption bridging and electrical neu- tralization of long chain inorganic polymer coagulants.In order to remove the low turbidity present in surface water, a novel metal-polysilicate coagulant was used to treat the raw water taken from Tanjiang River in Guangdong Province. This study on the effects of A1/Fe molar ratio on the performance of a complex compound formed by polysilicic acid, aluminium and ferric salt (PAFS) showed that PAFS with A1/Fe ratio of 10:3 seemed to have the best coagulation performance in removing turbidity and color. Experimental results showed that under the conditions of polymerization time of 15 d, sedimentation time of 12 min, and pH of 6-8,PAFS with A1/Fe molar ratio of 10:3 had the best coagulation efficiency and lowest residual A1 concentration. The turbidity decreased from 23.8 NTU to 3.23 NTU and the residual A1 concentration was only 0.165 mg/L in the product water. It could be speculated that colloidal impurities and particulate A1 were removed by adsorption bridging and electrical neutralization of long chain inorganic polymer coagulants.

关 键 词：Potable water treatment Metal-polysilicate coagulant Coagulation property Residual aluminum 

分 类 号：TU991.27[建筑科学—市政工程]