种植床模式下苦草修复富营养水体的种植密度优化研究

Optimization of vallisneria planting density for restoration of eutrophic water body under planting bed mode

研究了种植床模式下沉水植物苦草不同种植密度(750 g∕m^(3)、1500 g∕m^(3)、2000 g∕m^(3))对不同程度富营养化水体的净化效果,以筛选最优初始种植密度。结果表明:3种种植密度苦草对富营养化水体氮磷营养盐有明显的净化效果,自然水体中总氮(TN)的去除率为75%以上,模拟水体中TN的去除率达90%以上;种植密度为1500 g∕m^(3)和2000 g∕m^(3)的苦草净化效率高于种植密度为750 g∕m^(3)的处理;从植物生长势指标来看,种植密度为750 g∕m^(3)和1500 g∕m^(3)的苦草生长趋势优于种植密度为2000 g∕m^(3)的苦草。种植床模式下苦草的初始种植密度为1500 g∕m^(3)时可以适应不同程度富营养化水体,综合净化效益较好。

The purification effects of submerged plant vallisneria with different planting densities(750 g∕m^(3),1500 g∕m^(3)and 2000 g∕m^(3))on different degrees of eutrophic water under planting bed mode were studied in order to screen the optimal initial planting density.The results showed that the 3 planting densities of vallisneria had obvious purification effects on nitrogen and phosphorus nutrients in eutrophic water.The removal rate of total nitrogen(TN)in natural water was more than 75%,and that in simulated water was more than 90%.The purification efficiency of vallisneria with planting densities of 1500 g∕m^(3) and 2000 g∕m^(3) was higher than that of the treatment of planting density of 750 g∕m^(3).In terms of plant growth potential index,the growth trend of vallisneria with planting densities of 750 g∕m^(3) and 1500 g∕m^(3) was better than that with planting density of 2000 g∕m^(3).Under the planting bed mode,when the initial planting density of vallisneria was 1500 g∕m^(3),it could adapt to different degrees of eutrophic water,and the comprehensive purification benefit was good.