垂直潜流人工湿地除砷实验研究

Experiments research on As removal by vertical subsurface flow constructed wetlands

构建以锰砂和陶粒为填料和以蜈蚣草、灯心草为湿地植物的垂直潜流人工湿地系统,并模拟系统对水环境中砷的去除效果.实验结果表明:锰砂组人工湿地除砷能力大于相应的陶粒组;在进水砷质量浓度为500μg/L条件下,锰砂组人工湿地除砷高效稳定,维持在89%,陶粒组人工湿地除砷效率呈逐渐下降趋势,从48%~81%下降至29%~51%;与空白对照组相比,种植植物可提高湿地除砷效率;以陶粒为填料的各组砷去除率分别是50%(空白对照组),64%(蜈蚣草组)和74%(灯心草组);以锰砂为填料各组相应的砷去除率分别是89%,95%和91%;人工湿地对砷的去除率与温度和NH+4-N质量浓度呈显著正相关性,与PO3-4-P质量浓度呈显著负相关关系.

Vertical subsurface flow constructed wetlands were simulated to remove arsenic(As)from water,which manganese sand and ceramistie were chosen as substrate,while Juncus effuses and Pteris vittata L were chosen as wetland plants.The results show that As removal efficiency of manganese sand are higher than ceramistie.Manganese sand packed wetlands keep constantly 89% higher As reduction of approximate 500μg/L influent loads regardless planted or not.Ceramistie packed wetlands have decreasing removal efficiency from 48%~81% to 29%~51%.Contrasted to blank control wetland,the As removal efficiency is increased obviously with plant presence.The removal efficiency of ceramistie packed wetlands are 50%(blank control),64%(Pteris vittata L),74%(Juncus effuses),and the removal efficiency of manganese sand packed wetlands are 89%,95%,91%.The As removal efficiency has significant positive correlation with temperature and ammonia,while has negative correlation with phosphorus.