%0 Journal Article
%T Kinetics and Mechanism of Removing Microcystis aeruginosa Using Clay Flocculation<br>黏土絮凝沉降铜绿微囊藻的动力学及其作用机理
%A Pan Gang
%A Zhang Mingming
%A Yan Hai
%A Zou Hua
%A Chen Hao
%A <br>潘纲
%A 张明明
%A 闫海
%A 邹华
%A 陈灏
%J 环境科学
%D 2003
%I 
%X Twenty-six natural clays were studied for their kinetics of flocculating and removing algal cells of Microcystis aeruginosa. According to the 8 h equilibrium removal efficiencies and removal rates at a clay-loading of 0.7 g.L-1, all the 26 clays were classified into three categories. Type-I clay, which includes talc, ferric oxide, sepiolite, ferroferric oxide, and kaolinite, has an equilibrium removal efficiency greater than 90%, a t50 (time needed to remove 50% of the algae) of less than 30 min, and a t80 (time needed to remove 80% of the algae) of less than 2.5 h. Type-II clay, which includes argillanceous rocks, attapulgite, rectorite, illite, and argil, etc., has an equilibrium removal efficiency of 50%-80%, a t50 of less than 2.5 h, and a t80 of more than 5 h. Type-III clay consists of 14 minerals, including laterite, zeolite, mica, clinoptilolite, pumice, tripoli, feldspar and quartz, etc. with the removal efficiency less than 50%, and t50 > > 8 h. When the clay loading was decreased to 0.1-0.2 g.L-1, the 8 h equilibrium removal efficiencies for 25 clays declined to below 60%, except for sepiolite, a Type-I clay, which maintained around 90%. After the sepiolite was modified with Fe3+ to increase its surface charge (Zeta potential from -24.0 mV to +0.43 mV at pH 7.4), the initial removal rate was increased remarkably although its 8 h equilibrium removal efficiency was not improved substantially. As a comparison, the 8 h equilibrium removal efficiency of PAC was no greater than 40% at loadings of 0.02-0.2 g.L-1. Following the analysis of the flocculation mechanism it was concluded that the effect of bridging and netting may play a key role in the clay-algae flocculation processes, which may be important for selecting and modifying clays to improve significantly the removal efficiency.
%K Microcystis aeruginosa
%K clays
%K algal blooms
%K flocculation
%K mechanism
%K clay modification
%K bridging and netting
%K electrostatic neutralization<br>铜绿微囊藻
%K 黏土
%K 水华
%K 絮凝
%K 机理
%K 改性
%K 架桥网捕
%K 电中和
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=3FF3ABA7486768130C3FF830376F43B398E0C97F0FF2DD53&cid=A7CA601309F5FED03C078BCE383971DC&jid=64CD0AA99DD39F69401C615B85F123EF&aid=8F17B622B2DF2980&yid=D43C4A19B2EE3C0A&vid=B91E8C6D6FE990DB&iid=94C357A881DFC066&sid=CA4FD0336C81A37A&eid=F3090AE9B60B7ED1&journal_id=0250-3301&journal_name=环境科学&referenced_num=31&reference_num=25