沉水植物对湖泊沉积物氮磷内源负荷的控制及应用

    Controlling of Internal Phosphorus and Nitrogen Loading in Lake Sediment by Submerged Macrophytes and Its Application

    • 摘要: 该文阐述了沉水植物对湖泊沉积物N、P负荷控制的机理,并统计了相关研究中沉水植物对内源负荷的控制效果。沉水植物可以通过生长繁殖吸收、促进微生物代谢分解、改善沉积物理化环境、抑制沉积物再悬浮等多种途径降低沉积物中N、P含量或抑制N、P释放通量,从而有效控制水体内源负荷。根据相关模拟研究及野外研究得出沉水植物对沉积物中N、P的年平均去除量分别为1 136和387 mg·kg-1·a-1,且与沉积物的污染物中初始浓度呈正相关关系;与对照相比,沉水植物对水-沉积物界面N、P释放通量的抑制率分别可达62.6%~107.7%和41.2%~253.8%,因此恢复沉水植物是控制内源负荷的有效措施。但恢复沉水植物及对沉积物中N、P的去除效果受多种因素的影响,在应用过程中要选择合适物种进行搭配或采用必要的辅助措施,并通过在空间和工艺流程上与其他措施联合使用以达到更好的内源负荷控制效果。

       

      Abstract: The mechanisms and effects of submerged macrophytes in controlling lake sediment nitrogen (N) and phosphorus (P) internal loading are described and analyzed. Submerged macrophytes can decrease nitrogen and phosphorus contents in the sediment and reduce nitrogen and phosphorus release through several mechanisms, such as growth and reproductive assimilation, promotion of microbial metabolism and decomposition, improvement of physical and chemical environment of sediments, and inhibition of sediment resuspension. Statistical results based on simulation and field studies show that the average N and P removed from sediment by submerged macrophyte was 1 136 and 387 mg·kg-1·a-1, respectively, which was positively related with the initial concentrations of pollutants in sediment. With submerged macrophyte, the inhibition rate of N and P release was reduced by 62.6% to 107.7%, and 41.2% to 253.8%, respectively, compared to no-plant area. The restoration of submerged macrophyte is an effective measure to control the internal loading, while the removal of N and P is affected by many factors. When the submerged plant recovery technique is applied, the appropriate species should be used and collocated reasonably. To achieve better control effects, restoration of submerge macrophytes should be used in combination with other measures in space and process flow.

       

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