[目的]研究不同环境条件下塘堰湿地底泥氮磷的释放情况,为稻田排水过程中更好地发挥湿地作用提供参考.[方法]以湖北省漳河灌区两处理化性质较接近的典型塘堰湿地为研究对象,采用柱形管槽静态模拟不同水深处理下底泥氮磷释放对上覆水水质的影响.[结果]水流扰动会加速底泥中磷的释放.不稳定的水—泥环境以及溶解氧含量会影响微生物生长及硝化/反硝化作用的进行,良好的好氧—厌氧根区环境对于保持湿地的净化能力非常重要.不同的水质指标的净化,其适宜的湿地水深是不同的,底泥在25、45cm水深条件下,分别对上覆水中总氮、总磷浓度具有较好的净化效果.[结论]应根据不同的湿地、水质以及净化需求,确定最优的水稻灌区塘堰湿地水深,当底泥中营养物质富集到一定程度时,有可能形成二次污染,周期性的疏浚对于保证湿地的稳定运行至关重要.%[Objective]The release of nitrogen and phosphorus in sediment from pond wetlands under different environmental conditions was investigated for better use of wetland in rice paddy drainage. [ Method ]Two typical pond wetlands similar in physical and chemical characters were selected in Zhanghe Irrigation Area, Hubei Province. Effects of the release of nitrogen and phosphorus on water quality of overlying water were studied by means of static imitation. [Result] The results showed that the flow turbulence accelerated the release of phosphorus from sediment. Unstable water-soil environment and the content of dissolved oxygen affected the growth of microorganisms and the rate of nitrification/denitrification. Nice aerobic-anaerobic environment in the root zone was tremendously paramount for maintaining the purification capacity of wetland. For different water quality indicators, the appropriate water depth of wetland was different. As for total phosphorus, the purification effect was better when the water depth was 45 cm,and for total nitrogen,the better water depth was 25 cm. [Conclusion]Optimal water depth in pond wetland of rice irrigation area should be determined by wetland features,water quality and purification demands.When the nutrients in sediment accumulated to a certain extent, secondary pollution may occur. Accordingly the periodic dredging was key to ensure the treatment capacity and stable operation of wetland.
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