人工湿地中植物对低盐度养殖废水处理效果

分别构建种植美人蕉（Canna indica）、菖蒲（Acourus calamus）和千屈菜（Luthrum salicaria）的人工湿地，开展对低盐度养殖废水处理效果的模拟研究，设置进水中的C/N/P分别为50/10/1、25/5/1、25/5/2、25/5/3，盐度分别为0.5、1.0和2.0，水力停留时间分别为1 d、2 d、3 d和4 d，测定人工湿地对总氮、总磷和化学需氧量的去除率，出水中的氨氮、硝态氮、亚硝态氮和磷酸盐含量以及3种植物的生长状况。研究表明：当HRT=4 d，盐胁迫浓度为1，C/N/P为25/5/2（COD=50 mg/L，TN=5 mg/L，TP=4 mg/L）时，人工湿地装置TN、TP及COD去除率可达90%、97%和65%；不同植物的人工湿地系统中，美人蕉-人工湿地去除效果最佳，此时美人蕉体内叶绿素（SPAD值）、超氧化物歧化酶含量较高，丙二醛含量较低，分别为40.6、1 212U/g和2.45 nmol/g，氨基酸含量为1.82 %；盐胁迫浓度为1，C/N/P为25/5/2时，人工湿地内微生物群落结构得到优化，优势菌群为变形菌门（Proteobacteria），该菌门是污水处理中常见的功能性菌群。因此美人蕉-人工湿地能够处理低盐度养殖废水，能强化人工湿地处理效果，提高植物-微生物的协同去污和盐度耐受性，为滨海水体修复提供技术支撑。

Study on the treatment effect of plants in constructed wetland on low salinity culture wastewater

In the study, constructed wetlands with 3 plant species (Canna indica, Acourus calamus and Luthrum salicaria) were respectively built to obtain the optimal treatment conditions. In the treatment experiments, various factors were respectively arranged as follows: C/N/P (50/10/1, 25/5/1, 25/5/2, and 25/5/3), salinity (0.5, 1 and 2), and the HRT (1, 2, 3 and 4 d). The removal rate of TN, TP and COD in constructed wetland, the content of NH₃-N, NO₃-N, NO₂-N and PO₄^3- in influent and growth parameters of three plants were determined. The results showed that:When the HRT=4 d, the influent salinity of 1.0 and C/N/P was 25/5/2 (COD=50 mg/L, TN=5 mg/L, TP=4 mg/L), the highest removal rates of TN (90%), TP (97%) and COD (65%) were reached;Among the different plant and substrate combinations, the Canna indica wetland device had the best removal effect, the chlorophyll (SPAD value) and superoxide dismutase in Canna indica were relatively high, and the content of malondialdehyde is lower, respectively, 40.6, 1 212 U/g and 2.45 nmol/g, and the amino acid content was 1.82%;With influent salinity of 1 and C/N/P(25/5/2), the microbial community structure in the constructed wetland was optimized, and the dominant flora was Proteobacteria, which is a common functional flora in wastewater treatment. Therefore, Canna-constructed wetlands can treat low-salinity aquaculture wastewater, strengthen the treatment effect of constructed wetlands, improve the synergistic decontamination and salinity tolerance of plants-microorganisms, and provide technical support for coastal water body restoration.