不同结构草皮缓冲带对农田径流氮磷去除效果研究

通过对流过不同结构型式混播草皮缓冲带径流中污染物迁移影响的分析,研究其对农田径流氮磷的去除效果。结果表明,在TN、TP进水平均浓度分别为17.89 mg/L和1.04 mg/L的试验条件下,混播草皮缓冲带结构对农田径流TN、TP的去除能力具有明显差异,含有生态草沟的混播草皮缓冲带对TN、TP的去除能力明显强于单一缓坡和缓坡-阶梯结构的混播草皮缓冲带,其对径流水TN和渗流水TN的质量浓度削减率分别为51.08%和58.75%,对径流水TP和渗流水TP的质量浓度削减率分别为51.31%和65.29%。

Study on Efficiency of Sward Buffer Strips with Different Structures on Removal of Nitrogen and Phosphorus in Farmland Runoff

We analyzed the transport of pollutants in the runoff flowing through different structural types of mixed sward buffer strips,and studied the efficiency of various sward buffer strips on the removal of nitrogen and phosphorus in farmland runoff. The re-sults indicated that：under the test conditions that the average mass concentration of total nitrogen（ TN）and total phosphorus（ TP） at inflow port was 17. 89 mg/L and 1. 04 mg/L,respectively,the mixed sward buffer strips with different structures had significant differences in the removal capacity of TN and TP in farmland runoff;the mixed sward buffer strip with eco-grass ditch structure had obviously stronger TN and TP removal capacity than that with single gentle slope structure or with gentle slope-ladder structure,it decreased the mass concentration of TN in runoff water and seepage water by 51. 08% and 58. 75% respectively,and reduced the mass concentration of TP in runoff water and seepage water by 51. 31% and 65. 29% separately.