洱海调蓄多塘湿地磷截留效果及影响因子研究

Performance and factors of phosphorus interception in storing multi-pond wetlands in the Erhai Lake Basin

为考察洱海调蓄多塘湿地对磷的截留特征及效果,选取流域内12个调蓄多塘湿地进行定期跟踪调查,评估湿地中磷的截留性能,识别调蓄多塘湿地中磷的截留特征,解析调蓄多塘湿地中磷去除的主要影响因子.结果表明:调蓄多塘湿地的建立能够有效拦截面源污染携带的磷污染物,提升出水水质.湿地中η(PO_4^(3-)-P)、η(TP)和η(SS)平均截留效率分别为43.44%～93.88%、27.71%～89.67%和21.84%～62.12%.枯水期进水磷浓度高于丰水期,且枯水期磷的截留效率优于丰水期,枯水期间歇性断流提供足够的停留时间,有助于污染物的去除.ρo(TP)与ρi(PO_4^(3-)-P)(R=0.297)和ρi(TP)(R=0.304)显著正相关,η(TP)分别与调蓄多塘湿地进水ρi(PO_4^(3-)-P)(R=0.665)和ρi(TP)(R=0.740)呈显著正相关.调蓄多塘湿地对磷的持留效率主要取决于进水中磷酸根所占比例及总磷的浓度.该研究以期为调蓄多塘湿地在磷入湖负荷削减、流域污染治理和水体修复等领域的应用提供可靠的案例支持.

To investigate the characteristics and factors of phosphorus interception,phosphorus concentration from 12 storing multi-pond wetlands were analyzed.Evaluation of the removal efficiency and identification of the key factors of phosphorus removal were executed in the Erhai Lake Basin.The results showed that the water quality was effectively improved because phosphorus pollutants from the surface source pollution were intercepted in the storing multi-pond wetlands.The average interception efficiency value ofη(PO4^3-P),η(TP)andη(SS)were 43.44%~93.88%、27.71%~89.67%and 21.84%~62.12%,respectively.Both the phosphorus concentration of the influent and the efficiency of phosphorus interception in the dry season were higher,respectively,than those in the wet season.Intermittent outflow of effluent provided a residence time which was long enough for the removal of pollutants in the dry season.Whileρo(TP)had a significantly positive correlation withρi(PO4^3-P)(R=0.297)andρi(TP)(R=0.304).η(TP)showed a significant positive correlation withρi(PO4^3-P)(R=0.665)andρi(TP)(R=0.740).The efficiency of phosphorus removal primarily depended on the proportion of phosphate and the TP concentration of the influent.This study may provide support as an engineering case of multi-pond wetlands for the reduction of phosphorus into lakes,water pollution control in basins,and water restoration.