亚热带丘陵区绿狐尾藻人工湿地处理养猪废水氮磷去向

以亚热带丘陵区为研究区，采取野外定位观测的研究方法，选取耐高氮（N）、磷（P）的绿狐尾藻为湿地植物，建立稻草基质池+6级绿狐尾藻表面流湿地系统，湿地总面积1597 m²，水力负荷0.06~0.14 m·d^-1，水力停留时间31 d，研究此湿地系统对养猪废水（NH₄⁺-N：535.4~591.09 mg·L^-1、TN：682.09~766.96 mg·L^-1、TP：57.73~82.29 mg·L^-1和COD：918.4~1940.43 mg·L^-1）的治理效果，旨在为亚热带高负荷猪废水的生态治理提供参数依据.结果表明，湿地系统对NH₄⁺-N、TN、TP和COD的平均去除率为97.4%、97.1%、91.0%和90.2%，其中以CW1累积贡献率最大（37.3%、38.4%、43.3%和27.4%）.植物N、P吸收量在23.87~79.96 g·m^-2和5.34~18.98 g·m^-2之间，占湿地N、P去除量的19.1%和20.2%；底泥N、P吸附量在19.17~56.62 g·m^-2和10.59~26.62 g·m^-2之间，占去除量的19.8%和61.7%.湿地N、P去除率与影响因子间的关系表明，环境因子解释了湿地N、P去除率的79.9%和70.1%.其中，DO是湿地系统N去除的主要因子，底泥P吸附是P去除的关键.

Nitrogen and Phosphorus Removal in Surface Flow Constructed Wetland Planted with Myriophyllum elatinoides Treating Swine Wastewater in Subtropical Central China

The loss of nitrogen (N) and phosphorus (P) from aquaculture has caused eutrophication of freshwater systems. Here, surface flow constructed wetland (SFCW) planted with Myriophyllum elatinoides were used to treat swine wastewater from a medium-sized hoggery in subtropical Central China. Inflow concentrations of NH₄⁺-N, TN, TP, and COD ranged from 535.4 to 591.09, 682.09 to 766.96, 57.73 to 82.29, and 918.4 to 1940.43 mg·L^-1, respectively. The mean removal efficiencies of NH₄⁺-N, TN, TP, and COD were 97.4%, 97.1%, 91.0%, and 90.2%, respectively, and CW1 had the largest contributions of 37.3%, 38.4%, 43.3%, and 27.4%, respectively. Plant N and P uptake ranged 23.87-79.96 g·m^-2 and 5.34-18.98 g·m^-2, accounting for 19.1% and 20.2% of removal, respectively. Sediment N and P accumulation ranged 19.17-56.62 g·m^-2 and 10.59-26.62 g·m^-2, accounting for 19.8% and 61.7% of removal, respectively. Multiple linear regression showed that environmental factors explained 79.9% of the N removal and 70.1% of the P removal; DO was the main factor affecting N removal, and sediment adsorption was the key process in P removal. These results show that M. elatinoides constructed wetland can efficiently treat swine wastewater, thereby reduce the discharge of pollutants downstream.