水生植物滤床去除富营养化湖泊水中微囊藻毒素的研究

Removal of microcystins from eutrophic lake water by using hydrophyte filter bed eco-system

水生植物滤床（HFB）是一种用于净化富营养化水体的新型无基质型人工湿地系统。为考察HFB系统对水体中微囊藻毒素的处理效果，在太湖湖滨进行了中试研究。结果表明，在7-9月份，总藻毒素去除率在36．5％～75．8％之间，平均去除率为59．4％；胞外藻毒素平均去除率为50．0％；胞内藻毒素平均去除率为63．9％。不同植物组合型式的HFB系统对总藻毒素去除效果无显著差异。在水力负荷1．0-6．0m^3／（m^2·d）范围内，HFB系统去除藻毒素效果也无显著差异。系统对藻毒素的去除效果与富营养化指标（叶绿素-a、CODMn、TP）的处理效果成直线正相关性，藻毒素可作为一辅助指标从健康效应角度来反映富营养化水体水质改善情况。HFB系统在水源地藻毒素污染控制方面具有应用价值。

Hydrophyte filter bed （HFB） is a new kind of constructed wetlands without any substrate that applied to purify hyper-eutrophic surface water. A pilot scale HFB was established at shore of Taihu Lake to investigate the removal effect on microcystins from eutrophicated lake water. Results showed that, during July to September, the average removal efficiency of total microcystins using by HFB systems was 36.5%-75.8%, and ones of extracellular microcystins and intracellular microcystins was 50.0% and 63.9%, respectively. No significant difference appeared on removal ofmicrocystins by HFB systems with different plants arrangement. At the different hydraulic loading rate of 1.0-6.0 m^3·m^-2·d^-1, removal efficiency of microcystins had no remarkable change. The positive correlations between removal rates of microcystins and ones of some eutrophication indexes, that is Chl-a, CODMn and TP, were testified during HFB systems treating water. The amount of microcystins could be an accessorial index of eutrophication water quality improvement from the point of health effect. HFB is proved a valuable technique for microcystin pollution control in source water area.