不同配置人工湿地植物群落对生活污水净化效果

Effects of Sewage Purification by Different Plant Communities in the Constructed Wetland

植物群落是湿地生态系统的重要组分,湿地植物群落物种组成对水体净化功能具有重要作用。选择茭草(Zizania caduciflora)、鸢尾(Iris tectorum)、菖蒲(Acorus calamus)和眼子菜(Potamogeton pectinatus)4种湿地常见物种和CK(无植被)的人工湿地,对不同湿地植物群落净化污水的效果进行了对比研究。结果表明:4种不同植物群落人工湿地对生活污水净化效果不同,其中BOD5,CODCr,TN,NH+4-N,NO-3-N,TP质量浓度随时间变化逐渐降低,相同月份BOD5,CODCr,TN,NH+4-N,NO-3-N,TP质量浓度大致表现为CK>茭草>鸢尾>菖蒲>眼子菜;BOD5,CODCr,TN,NH+4-N,NO-3-N,TP去除率随时间变化逐渐增加,相同月份去除率大致表现为眼子菜>菖蒲>鸢尾>鸢尾,局部有所波动。4种不同植物群落地上生物量变化范围为25.9~39.6 g/m2,大致表现为眼子菜>菖蒲>鸢尾>茭草,其中眼子菜和菖蒲差异不显著(p>0.05),鸢尾和茭草差异不显著(p>0.05);地下生物量变化范围在31.2~41.3 g/m2,大致表现为眼子菜>菖蒲>鸢尾>茭草,不同植物差异均显著(p<0.05);地下N,P累积量均高于地上N,P累积量,大致表现为眼子菜>菖蒲>鸢尾>茭草,不同植物地上和地下P累积量差异均不显著(p>0.05)。相关性分析表明,茭草、鸢尾、菖蒲和眼子菜TP与P累积量呈显著正相关;TN,NH+4-N,NO-3-N与N累积量呈显著正相关;CODCr,BOD5与地下生物量呈显著正相关,与地上生物量和P累积量没有显著相关性(p>0.05)。由此表明,地下生物量在净化水质过程中起着重要作用,根系发达的植物具有更强的净化效果。

Hygrophyte is an important part of a constructed wetland system.Species composition of wetland plant communities are important in the water-cleaning functions of wetlands.Four common wetland plants(Zizania caduciflora,Iris tectorum,Acorus calamus and Potamogeton pectinatus)in natural wetlands were chosen.The effect of the different plant communities on the treatment of domestic sewage were compared.The results showed that the four different plant communities in constructed wetlands had different impact,and the concentrations of BOD5,CODCr,TN,NH+4-N,NO-3-N,TP deceased with the time,decreased in the order:CK>Zizania caduciflora>Iris tectorum>Acorus calamus>Potamogeton pectinatus;the purification effects of BOD5,CODCr,TN,NH+4-N,NO-3-N,TP increased with the time,decreased in the order:CK>Zizania caduciflora>Iris tectorum>Acorus calamus>Potamogeton pectinatus;the aboveground biomass ranged from 25.9~39.6 g/m2,following the order:Zizania caduciflora>Iris tectorum>Acorus calamus>Potamogeton pectinatus,effects of Zizania caduciflora and Iris tectorum had no significant difference(p>0.05),effects of Acorus calamus and Potamogeton pectinatus had no significant difference(p>0.05);the belowground biomass ranged from 31.2~41.3 g/m2,following the order:Zizania caduciflora>Iris tectorum>Acorus calamus>Potamogeton pectinatus,and presenting the significant difference(p<0.05);N and P accumulations in belowground were higher than aboveground,which decreased in the order:Zizania caduciflora>Iris tectorum>Acorus calamus>Potamogeton pectinatus,difference of P accumulation between the aboveground and belowground was not significant(p>0.05).The correlation analysis showed that there was the significant positive correlation between TP and P accumulations in water bamboo,irises,calamus and brassica.TN,NH+4-N,NO-3-N and N accumulations were significantly positively correlated.CODCr and BOD5 were positively correlated with underground biomass,but not correlated with aboveground biomass and P accumulation.In total,the underground biomass plays an important role in the process of purifying water quality,and the plants with well developed root have the greater clean-up effect.