芦苇湿地对氮磷污染物质的净化效应及其价值初步估算——以苏北盐城海岸带芦苇湿地为例

Primary Valuation on the Purification Function of Reed Wetland for N,P——A Case Study in the Coastal Yancheng

对在不同污灌强度下的苏北盐城海岸带两片芦苇湿地的调查发现:在新洋港,氮磷营养物质在2km长的灌渠中的自净率为18.3%～45.6%;苇田净化率在87.08%～95.65%之间;在黄沙港,由于灌溉水体中污染物含量过高,灌渠中的自净率在6.5%～8.7%之间,苇田净化率为61.3%～86.2%,均低于新洋港,而芦苇湿地单位面积净化效果则是新洋港处的3.2～18.5倍。净化效果的差异,说明对苏北盐城海岸带芦苇湿地净化功能的利用可能还存在较大的潜力和空间。单位面积的芦苇净化价值为1120元/hm2·a,比国际估算结果偏低,表明对海岸湿地这种处于生态过渡带的湿地类型中营养物质及其他污染物质的净化研究还有待进一步的实验和研究,这方面工作的开展也具有现实的重要性和必要性。

The purification function of two patches of reed wetland, which was managed by effluent irrigation with different intensity in the coastal Yancheng, was surveye. The results show that, under general irrigation by river water （at Xinyanggang）, the purification rates for N and P are 18.3 %-45.6 % in a 2 km long channel and 87.08%-95.65% in the reed field. Under effiuentirri gation with sewage from paper mill （ at Huangshagang ）, the purification rates for N and P are 6. 5 %-8.7 % in the channels and 61.3%-86.2% in the reed field. At Huangshagang, about 0.095t of TN, 0.026t of TP can be removed from reed wetland per hectare per year, which are 3.2,18.5 times the purification efficiency of reed wetland by general irrigation with river water, respectively. The gap of the purification efficiency between the general irrigation reed wetland and the effluent irrigation reed wetland, shows that there are great potential and space for utilizing the purification functions for nutrients of the reed wetlands in the coastal Yancheng. The reed purification value, 1 120 ￥ per hectare per year, is lower than the international estimated resultly. That indicates, further experiments and researches of the purification function of reed wetland for nutrients and other pollutants are needed in the coastal Yancheng, and such researches are also of practical importance and necessity.