几种沟渠植物对村镇生活污水氮、磷去除效率的对比研究

Comparative Study on Removing Efficiency of Nitrogen and Phosphorus from Town Sewage Water by Ditch Plants

通过调查四川盆地主要沟渠植物的生长特征,选取7种乡土优势沟渠植物菖蒲、水蓼、美人蕉、酸模、野薄荷、水芋、黑麦草作为污水净化供试植物。通过模拟小城镇排水沟渠的土壤—水体—植物生境的盆栽实验,计算沟渠植物对污水中氮、磷的去除净化能力。结果表明,美人蕉、水蓼、黑麦草三种植被对氮、磷的富集率达14.41%—33.78%,自身净化能力较强;在有植株处理下的污水中氮、磷去除净化效率可达93%以上。各植物对污水氮的净化效率依次为:黑麦草>薄荷>酸模>水蓼>水芋>菖蒲>美人蕉;对污水中磷的净化率依次为:水蓼>黑麦草>水芋>薄荷>美人蕉>菖蒲>酸模。综合考虑四川盆地村镇分散生活污水的污染特征、沟渠植物的生物量和氮磷的去除效果,宜引入黑麦草、水蓼、美人蕉等植物恢复村镇排水沟渠植被,以达到理想的污水净化效果。

Seven typical native wetland plants calamus, smartweed, canna, sorrel, wild mint, calla, ryegrass in drainages in the Sichuan Basin were selected as the test plants for water purification. This paper calculated the nitrogen and phosphorus removal capacities by ditch plants, through the sim- ulation of the small towns of drainage ditches potted plant experiment of soil - water - plant habitat. The results showed that canna, calla and ryegrass hade strong abilities of self- purification with the nitrogen and phosphorus absorption rates as 14.41% - 33.78 %. Nitrogen and phosphorus removal rate by different plants on sewage water reached to more than 93 %. Nitrogen purification efficiency of different plants on sewage water followed by ryegrass 〉 mint 〉 sorrel 〉 smartweed 〉 calla 〉 calamus 〉 canna, while phosphorus purification efficiency followed by smartweed 〉 ryegrass 〉 calla 〉 mint 〉 canna 〉 calamus 〉 sorrel. Considering characteristics of water pollution, plant biomass and nitrogen and phosphorus purification efficiencies, ryegrass, smartweed and canna may be chosen as water purifying plants in drainage ditches in small towns in Sichuan Basin, so as to achieve ideal ef- fects on water purification.