滴水湖底泥内源营养盐释放行为与曝气运行模式的关系

Responses of sediment endogenous-nutrients release behaviors in Dishui Lake to aeration operation modes

以滴水湖上覆水及底泥为研究对象,探讨了不同曝气运行模式对滴水湖底泥内源营养盐释放行为的影响,为曝气原位修复滴水湖等滨海盐碱化地区富营养化人工湖泊提供技术参考。结果表明,曝气能有效降低滴水湖上覆水体NH+4-N浓度,但此类滩涂底泥中较高的盐度能促进内源NH+4-N的释放并抑制硝化作用,使其NH+4-N削减率明显低于城市重污染河道;静置组TP浓度有所升高,而间歇曝气组及连续曝气组TP削减率分别为63.6%和38.5%,说明间歇曝气能有效降低上覆水体中的TP浓度;与曝气修复城市重污染河道相比,滴水湖较高的盐度及pH不利于TN去除,其中间歇曝气组对上覆水TN的控制优于连续曝气组与静置组;间歇曝气运行模式更适合于滴水湖等滨海盐碱化地区富营养化人工湖泊的底泥修复。

The responses of endogenous-nutrients release behaviors to different aeration operation modes were investigated using the overlying water and sediment from Dishui Lake as research object.This thesis could provide technical references for in-situ aerated remediation of eutrophic coastal salinization artificial lake such as the Dishui Lake.Results showed that aeration could effectively reduce the concentration of NH4^＋-N in overlying water.The relatively lower ammonia removal efficiency could be attributed mainly by the increased ammonia release as well as the nitrification inhibition due to the higher salinity of bench sediment,compared with highly polluted urban river.The reduction rate of TP under intermittent-aeration and continuous-aeration was 63.6%and 38.5%,respectively,while the TP level was increased without aeration.Additionally,the relatively high level of salinity and pH was detrimental to the removal of TN,which might account for the worse TN removal performance of Dishui Lake than that of highly polluted urban river.Taken together,the intermittent aeration could be recognized as a more suitable operating mode for the remediation of eutrophic artificial coastal salinization lake sediments.