草本缓冲带优化配置对氮磷的去除效果

Effects of Nitrogen and Phosphorus Removal by Optimizing the Configuration of Herbaceous Buffer Strips

利用自行设计的小型试验装置模拟缓冲带,选择东北地区草木犀、白三叶、马唐、夏枯草4种常见植物,通过人工配水模拟农田径流水,采用草种不同栽种方式及草皮与其他生物处理方式相结合的方法,开展缓冲带对污染物的净化效果试验研究。结果表明,在渗流中,草种不同栽种方式和草皮与其他生物处理方式结合的缓冲带,3种混栽方式的NH4+—N、全P的去除效果最高分别为59.80%、56.81%。在径流中,草种不同栽种方式中3种混栽方式的NH4+—N、全P的去除效果最高分别为23.30%、22.30%;草皮与其他生物处理方式结合缓冲带,3种混栽+小沟对全P去除效果最高达27.4%,3种混栽+人工浮床对NH4+—N去除效果最高,达30.1%。在本试验条件下,3种混栽方式对渗流的净化效果较好,而草皮与其他生物处理方式结合的缓冲带对径流有较好的净化效果。

An experiment was conducted to study the effects of runoff pollutants removal in a self-designed lab-scale model.Four species of economic plants（Melilotus suaveolens,Trifolium repens,Digitaria sanguinalis and Prunella asiatica） were selected from northeast China as experimental materials.The purifying effects of different configuration ways of plantings and sod combined with other biological treatments were studied through simulating farmland runoff with artificial water.Results showed that,among all the configuration ways,the mixed planting of M.suaveolens,T.repens and D.sanguinalis had high removal capacity of NH＋4-N and total phosphorus in seepage flow,and the removal rate of NH＋4-N reached 59.80%,and that of total phosphorus was 56.81%;in the runoff,the highest removal rates of NH＋4-N and total phosphorus were 22.30% and 23.30% for different planting ways.Considering different configuration ways of sod combined with other biological treatments,the mode of mixed planting of M.suaveolens,T.repens and D.sanguinalis with a small ditch had a high total phosphorus removal rate（27.4%）,and the NH＋4-N removal rate of the mode of mixed planting of M.suaveolens,T.repens and D.sanguinalis with artificial floating bed reached 30.1%,which showed the best removal effect. In this experimental condition,the mode of the mixed planting of M.suaveolens,T.repens and D.sanguinalis has better purifying effect on the seepage flow;while the turf combined with other biological treatments exhibits better removal effects on runoff pollutants.