选择茭白(Zizania caduciflora)、鸢尾(Iris tectorum)、美人蕉(Canna indica)和芦苇(Phragmites australis),连续4年(2015—2018)研究了不同植物配置下人工湿地对辽河水质净化作用。结果 表明:2015—2018年人工湿地不同植被对BOD5,CODCr,TN和TP去除率随着年份的增加而增加; 不同年份BOD5,CODCr,TN和TP去除率均表现芦苇和茭白显著高于美人蕉和鸢尾(p<0.05),其中芦苇和茭白差异不显著(p>0.05),美人蕉和鸢尾差异不显著(p>0.05)。人工湿地地上生物量、地下生物量、N累积量和P累积量随着年份的增加而增加; 不同年份芦苇和茭白地上生物量均显著高于美人蕉和鸢尾(p<0.05),其中芦苇和茭白的地上生物量差异不显著(p>0.05),美人蕉和鸢尾的地上生物量差异不显著(p>0.05)。人工湿地土壤有机碳、全氮、全钾、速效磷、碱解氮含量呈一致的变化规律,随着年份的增加而增加; 不同年份土壤有机碳、全氮、全磷、全钾、速效磷、碱解氮含量均表现芦苇和茭白显著高于美人蕉和鸢尾(p<0.05),其中芦苇和茭白差异不显著(p>0.05),美人蕉和鸢尾差异不显著(p>0.05); 不同年份湿地土壤全磷含量差异不显著(p>0.05)。人工湿地土壤微生物量碳、氮、磷呈一致的变化规律,随着年份的增加而增加; 不同年份湿地土壤微生物量碳、氮、磷含量均表现芦苇和茭白显著高于美人蕉和鸢尾(p<0.05),其中芦苇和茭白差异不显著(p>0.05),美人蕉和鸢尾差异不显著(p>0.05); 不同年份湿地土壤微生物量磷含量差异不显著(p>0.05)。地下生物量、N累积量、P累积量、土壤全氮、全磷与TN和TP去除率呈显著正相关(p<0.05); 土壤速效磷、碱解氮、微生物量碳、微生物量氮与BOD5和CODCr去除率呈显著正相关(p<0.05)。
Plants are important components of constructed wetland ecosystem. Zizania caduciflora, Iris tectorum, Canna indica and Phragmites australis were selected to study the purification effect of constructed wetlands on water quality of Liaohe River under different plant configurations for four consecutive years(2015—2018). The removal rates of BOD5, CODCr, TN and TP by different types of vegetation in constructed wetlands from 2015 to 2018 had increased over the years. The removal rates of BOD5, CODCr, TN and TP were significantly higher than those of Canna indica and Iris tectorum(p<0.05)in different years, but there was no significant difference between the removal rates of Phragmites australis and Zizania aquatica(p>0.05), while there was no significant difference between removal rates of Canna indica and Iris tectorum(p>0.05). The aboveground biomass, underground biomass, N accumulation and P accumulation of constructed wetland had increased over the years. The aboveground biomass of Phragmites australis was significantly higher than that of Canna indica and Iris tectorum(p<0.05)in different years, and there was no significant difference between the biomass of Phragmites australis and Zizania aquatica(p>0.05), while there was no significant difference between the biomass of Canna indica and Iris tectorum(p>0.05). The contents of soil organic carbon, total nitrogen, total potassium, available phosphorus, alkali-hydrolyzed nitrogen of constructed wetland showed consistent change patterns, and had increased over the years. The contents of organic carbon, total nitrogen, total phosphorus, total potassium, available phosphorus and alkaloid nitrogen were significantly higher than those in Canna indica and Iris tectorum(p<0.05)in different years, but there was no significant difference between Phragmites australis and Zizania aquatica(p>0.05), and no significant difference between the contents of Canna indica and Iris tectorum(p>0.05). There was no significant difference in soil total phosphorus contents in different years(p>0.05). The soil microbial biomass carbon, nitrogen and phosphorus of the constructed wetlands changed in a consistent manner and had increased over the years. Soil microbial biomass of carbon, nitrogen and phosphorus of constructed wetlands Phragmites australis and Zizania aquatica were significantly higher than those of the constructed wetlands with Canna indica and Iris tectorum(p<0.05), and there was no significant difference between soil microbial biomass under the constructed wetland with Phragmites australis and Zizania aquatica(p>0.05), while there was no significant difference between Canna indica and Iris tectorum(p>0.05). There was no significant difference in soil microbial biomass phosphorus content in different years(p>0.05). Underground biomass, N accumulation, P accumulation, soil total nitrogen, total phosphorus were significantly positively correlated with TN and TP removal rates(p<0.05). Soil available phosphorus, alkali-hydrolyzed nitrogen, microbial biomass carbon and microbial biomass nitrogen were significantly positively correlated with BOD5 and CODCr removal rates(p<0.05).
