Coagulation performance and floc properties of Microcystis aeruginosa in the presence of humic acid
Coagulation performance and floc properties of Microcystis aeruginosa in the presence of humic acid
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DOI：
10.2166/ws.2014.119
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发表时间：
2015-04
期刊：
影响因子：
1.7
通讯作者：
Peixia Cheng;Fei Ge;Xingwang Liu;Xiaoshuang Zeng;Biao Chen
中科院分区：
文献类型：
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作者：
Peixia Cheng;Fei Ge;Xingwang Liu;Xiaoshuang Zeng;Biao Chen
腐殖酸（HA）对原水中藻类的混凝去除效果有显着影响。进行了一系列罐式测试，以研究聚氯化铝在 HA 存在下的混凝性能以及铜绿微囊藻（一种单细胞蓝藻）的絮凝特性。同时通过测量上清液的zeta电位来探讨其混凝机制。结果表明，在pH 8.0时，低浓度HA（2 mg/L）和在pH 6.0时，高浓度HA（8 mg/L）对叶绿素-a（Chl-a）的去除效果最佳。在最大混凝效率下，絮体结构更加致密、尺寸更大，计算得到的分形维数（D f）也更大。相同混凝条件下D f 的变化与Chl-a 去除效率的变化一致。推测电荷中和是去除低浓度HA藻细胞的主要机制，而电荷中和、聚集和桥接过程共同作用去除高浓度HA藻细胞。这些结果提供了关于如何在水处理中存在不同浓度 HA 的情况下实现最佳藻类去除效率的见解。
Coagulation removal of algae in raw water could be significantly affected by humic acid (HA). A series of jar-tests were conducted to investigate the coagulation performance with polyaluminum chloride and floc properties of Microcystis aeruginosa , a unicellular cyanobacteria, in the presence of HA. Meanwhile the coagulation mechanism was explored through the measurement of zeta potential of the supernatant. The results showed that an optimal removal efficiency of chlorophyll-a (Chl-a) was obtained at pH 8.0 with a low concentration of HA (2 mg/L) and at pH 6.0 with a high concentration of HA (8 mg/L). The floc structure was more compact and bigger-sized and the calculated fractal dimension ( D f) was larger at maximum coagulation efficiency. The variation of D f was consistent with that of Chl-a removal efficiency under the same coagulation conditions. Charge neutralization was inferred to be the dominant mechanism to remove algal cells with low concentration of HA, while charge neutralization, gathering and the bridging process worked together to remove algal cells with a high concentration of HA. These results provide insight on how to achieve an optimal removal efficiency of algae in the presence of different concentrations of HA in water treatment.