壳聚糖-高岭土复合体去除铜绿微囊藻的试验研究

Removal of Microcystis aeruginosa by Chitosan-kaolinite Composite

利用室内模拟试验,研究了壳聚糖和高岭土单独及复合作用对铜绿微囊藻的去除效果。以250mL烧杯作为试验容器,纯种藻为试验用藻,以叶绿素a和浊度表征藻液浓度的变化。结果表明,单独使用高岭土除藻效率较低,增加高岭土用量难以提高藻的去除率;单独使用壳聚糖对藻的去除效果较好,但是藻的絮凝沉降速度较慢。壳聚糖-高岭土复合体可以明显加快藻类的沉降速率,改善除藻效果。

Algal bloom is common in lakes throughout the world as a consequence of eutrophication. It is necessary to develop effective and environment-friendly materials to control algal bloom in lakes, especially in recreational waterbodies. A laboratory experiment was carried out to investigate the removal efficiency of Microcystis aeruginosa by chitosan, kaolinite, and cbitosan-kaolinite composite respectively from water. Experiments were conducted in 250 mL beakers with single species Microcystis aeruginosa as experimental alga. The initial chlorophyll-a concentration of algae culture solution was 100-200 μg· L^-1 and its turbidity was 35-40 NTU. After the addition of chitosan, kaolinite, and chitosan-kaolinite composite into algae solutions respectively, the solutions were stirred at a speed of 100 r·min^-1 for 10 min, and then stirred at a speed of 50 r·min^-1 for 20 min. After a certain standing time, the supernatant liquid samples of stirred algae solutions were taken for the analysis of chlorophyll-a and turbidity to assess the algae removal efficiency. Results show that the removal efficiency of algae is low by kaolinite alone, and it can not be improved by increasing the amount of kaolinite. The removal efficiency by chitosan is considerably high; however, the algae＇ s flocculation and settling become slow. Composite of chitosan-kaolinite can improve the settling rate of algae, which is promising in the algae removal in practice.