垂直扰动对深谷型湖泊红枫湖底泥覆盖的效果

Effect of Vertical Disturbance on Sediment Coverage of Hongfeng Lake with Barranca Type

为构建底泥活性覆盖系统进而有效地控制湖泊底泥内源污染,以脱碱赤泥为主料,粉煤灰、粘土和碳酸钙为辅料,采用烧结法制作了不同配比的底泥覆盖材料,研究其对内源污染物的控制效果。结果表明：1）覆盖各处理溶解氧为2.62～5.98mg/L,对照组为0.74～2.65mg/L,覆盖可改善上覆水体溶解氧水平。2）覆盖各组中除处理2和处理4外,其余处理总磷均为低检出或未检出,对照组在第12、16和20天依次检出0.03mg/L、0.04mg/L和0.13mg/L;化学需氧量为6～71mg/L,对照组则为21～84mg/L,对照组总磷和化学需氧量均随时间推移呈渐增趋势;除处理3和处理6外,其余处理对氨氮控制效果不理想。3）优化原料配比可使上覆水体Cu、Pb、Zn、Cr、Cd、Fe、Mn、Ca和Mg处于安全浓度范围,不会增加水体金属元素的积累。从对内源污染物的控制效果和上覆水体水质的稳定性两方面综合考虑,处理6（赤泥38.9%,粘土14.4%,粉煤灰38.9%,碳酸钙7.8%）最适于深谷型湖泊底泥污染原位控制。

The control effect of the sediment coverage materials made from de-alkalized red mud,coal ash,clay and calcium carbonate with different proportion on endogenous pollutants of Hongfeng Lake to build the active sediment cover system for controlling endogenous pollution of lake sediments effectively.The results showed that：1）The dissolved oxygen（DO）of different cover treatments and CK is 2.62～5.98mg/L and 0.74～2.65mg/L,which indicates that the coverage can improve DO level of the overlying water;2）TP of different treatments except treatment 2and treatment 4is not detected but TP of CK after12 d,16dand 20 dis 0.03mg/L,0.04 mg/L and 0.13 mg/L.The chemical oxygen demand（COD）of different treatments and CK is 6～71 mg/L and 21～84mg/L.TP and COD of CK both show a gradual increase trend.There was no evidence for decrease of NH3-N after coverage,except treatment 3and 6;3）The coverage material made from different raw materials with the optimized ratio does not increase heavy metals accumulation of water body,and the concentration of Cu,Pb,Zn,Cr,Cd,Fe,Mn,Ca and Mg in the overlying water still is in the safety range.The coverage material made from 38.9% de-alkalized red mud,14.4% clay,38.9% coat ash and 7.8% calcium carbonate is most suitable to controlling sediment pollution in lakes with barranca type according to control effect of endogenous pollutants and water quality stability of the overlying water.