湿地植物对农村生活污水中氮磷的净化作用

[目的] 探讨水生植物修复技术对农村生活污水的治理效果，为乡村生态综合治理提供思路借鉴和参考资料。[方法] 通过模拟室内控制试验的方法，选取不同生态型的6种湿地植物为研究对象，分析植株生物量、去除率、植物积累量、底泥吸附量等多项指标变化，研究不同水生植物及其组合对污水中氮磷的净化效果差异以及水生植物系统的脱氮除磷特征。[结果] 无论单一种植组或混合种植组，水生植物系统对污水中TN，NH₄⁺-N，TP均有较好的净化效果，平均去除率分别达到96.6%，93.2%和95.9%，显著高于对照组。单一种植的再力花长势最好，鸢尾地上和地下部分生物量的比值最大，混合种植的美人蕉以及单一种植的梭鱼草相对生长速率最低。挺水植物对氮素的吸收作用更好，苦草对磷的吸收效果更好。植物吸收氮、磷占系统总去除量的比例在6.9%~18.3%和4.1%~13.6%之间，底泥吸附氮、磷占总去除量的比例在14.0%~31.5%和26.3%~68.4%之间。微生物及其他植物的间接作用是植物系统脱氮除磷的主要影响因素。[结论] 再力花、鸢尾及苦草的镶嵌组合是在淮北平原区湿地植物种植的理想选择。对水生植物的组合方式、数量、时间等进行优化配置，能够有效用于农村生活污水的净化。

Purification Effects of Various Aquatic Plants on Nitrogen and Phosphorus in Rural Sewage

[Objective] The effects of aquatic plant remediation technology on rural domestic sewage characteristics were studied in order to provide ideas and reference information for comprehensive and ecological treatment methods in rural areas.[Methods] Using simulated indoor controlled tests, wetland plants of six different ecological types were selected for measurement and analysis of plant biomass, and removal rate, plant accumulation, sediment adsorption capacity of nitrogen and phosphorus. Purification efficiency and removal characteristics of different plants for combinations of nitrogen and phosphorus in wastewater were also studied.[Results] Both single species and combinations of plant species used as an aquatic plant system resulted in a good level of purification of TN, NH₄⁺-N, and TP from sewage. The average removal efficiencies of hydrophyte systems for TN, NH₄⁺-N, and TP were 96.6%, 93.2%, and 95.9%, respectively, and these values were significantly higher than the values observed in the control group. Thalia dealbata in single-crop cultivation grew best. The ratio of aboveground to underground biomass of Iris tectorum was the largest. The relative growth rates of Canna indica in combination planting and Pontederia cordata in single planting were the lowest. Emergent plants had better absorption of nitrogen, and Vallisneria natans had better absorption of phosphorus. The proportion of nitrogen and phosphorus uptake by plants in the total removal capacity of the system was 4.5%-17.1% and 4.1%-13.6%, respectively, and the proportion of nitrogen and phosphorus accumulated by sediment was 11.6%-26.2% and 26.3%-68.4%. Microorganisms and the indirect effects of other plants were the most important mechanisms of nitrogen and phosphorus removal in plant systems.[Conclusion] T. dealbata, I. tectorum, and V. natans and their mosaic combination were ideal wetland plants for purification of rural sewage in Huaibei Plain. Optimizing the combination, number of species, and timing of aquatic plants will be useful for purification of sewage in rural areas.