Wetland Ecosystem Research Station of Hangzhou Bay, Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou, 311400, Zhejiang, China.
East China Forest Inventory and Planning Institute, State Forestry Administration, Hangzhou, 310019, Zhejiang, China.
Environ Sci Pollut Res Int. 2020 Jun;27(17):21487-21496. doi: 10.1007/s11356-020-08497-7. Epub 2020 Apr 10.
Salinity has a significant impact on the sewage treatment efficiency of constructed wetlands (CWs), as well as affecting the greenhouse gas emissions of CWs. A lab-scale CW simulation system was constructed to observe the treatment efficiency and greenhouse gas flux occurring in CWs at different influent salinities (0%, 0.5%, 1.0%, 1.5%, and 2.0%). The results show that (1) the removal rates of COD, TN, NH-N, NO-N, and TP reach the highest at salinity of 0 or 0.5%. And the lowest removal rates are all at a salinity of 2.0%. (2) The emission flux of CO, CH, and NO in CWs varies with an increase in salinity. The trends of CO and CH emission flux were consistent with those of COD reduction rate. However, it was opposite for NO flux to that of TN, NH-N, and NO-N removal rate. Affected by salinity, the greenhouse gas emission flux in this study is generally lower than what was reported in literature. (3) Correlation analysis showed that CO and CH emission fluxes were positively correlated with the COD reduction rate. NO emission flux was negatively correlated with the removal rates of TN, NH-N, and NO-N. The results suggest that different pollutants are inhibited by salinity to different degrees. COD is more affected by salinity than nitrogen and phosphorus, while nitrogen is more easily inhibited by salinity than phosphorus. CWs can have a high removal rate of pollutants in treating low-salinity wastewater. Although increased salinity reduces treatment efficiency of wastewater to some extent, it also inhibits the emission of CO and CH.
盐度对人工湿地（CWs）的污水处理效率有重大影响，同时也影响 CWs 的温室气体排放。构建了一个实验室规模的 CW 模拟系统，以观察不同进水盐度（0%、0.5%、1.0%、1.5%和 2.0%）下 CWs 中的处理效率和温室气体通量。结果表明：（1）在盐度为 0 或 0.5%时，COD、TN、NH-N、NO-N 和 TP 的去除率最高，而盐度为 2.0%时的去除率最低。（2）CWs 中 CO、CH 和 NO 的排放通量随盐度的增加而变化。CO 和 CH 排放通量的趋势与 COD 去除率的趋势一致。然而，NO 通量与 TN、NH-N 和 NO-N 的去除率相反。受盐度影响，本研究中的温室气体排放通量通常低于文献报道的水平。（3）相关分析表明，CO 和 CH 排放通量与 COD 去除率呈正相关，NO 排放通量与 TN、NH-N 和 NO-N 的去除率呈负相关。结果表明，不同污染物受盐度的抑制程度不同。COD 比氮和磷受盐度的影响更大，而氮比磷更容易受盐度的抑制。CWs 在处理低盐度废水时可以具有较高的污染物去除率。尽管增加盐度在一定程度上降低了废水的处理效率，但它也抑制了 CO 和 CH 的排放。
