College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, PR China.
Jiangsu Environmental Engineering Technology Co., Ltd, Nanjing, 210036, PR China.
Chemosphere. 2023 Nov;340:139872. doi: 10.1016/j.chemosphere.2023.139872. Epub 2023 Aug 18.
The improvement effect of Tubifex tubifex on the pollutant removal efficiencies (REs) of vertical flow constructed wetlands (VF-CWs) treating wastewater with various C/N ratios was explored. The experiment was conducted in pilot-scale saturated VF-CWs, being added different densities of T. tubifex and fed synthetic wastewater with successive C/N ratios of 0.5, 1.5, 3.0 and 6.0. The results suggest that T. tubifex addition and the influent C/N ratio had an interactive effect, i.e., T. tubifex addition improved NO-N, NH-N, TN and COD REs by 36.7%, 56.5%, 22.6%, and 10.0%, respectively, under low C/N ratios, while high C/N ratios inhibited this improvement. Low-density T. tubifex addition significantly increased substrate dissolved oxygen (DO) by retarding excessive soil organic matter (OM) accumulation. With T. tubifex addition, an improvement in bacterial diversity, the relative abundance of N-cycle and fermentative bacteria, and N-cycle functional genes was only observed in substrates under low C/N ratios. T. tubifex can improve the purification function of saturated VF-CWs, but this strategy strongly depends on both the influent C/N ratio and density of T. tubifex addition.
研究了添加颤蚓（Tubifex tubifex）对不同 C/N 比下垂直流人工湿地（VF-CWs）处理废水的污染物去除效率（REs）的改善效果。该实验在中试规模的饱和 VF-CWs 中进行，添加了不同密度的颤蚓，并连续用 C/N 比为 0.5、1.5、3.0 和 6.0 的合成废水进行喂养。结果表明，颤蚓添加和进水 C/N 比存在交互作用，即在低 C/N 比下，颤蚓添加分别提高了 NO-N、NH-N、TN 和 COD 的 REs 36.7%、56.5%、22.6%和 10.0%，而高 C/N 比则抑制了这种改善。低密度颤蚓添加通过延缓过多土壤有机质（OM）积累，显著提高了基质溶解氧（DO）。颤蚓添加后，仅在低 C/N 比下的基质中观察到细菌多样性、氮循环和发酵菌的相对丰度以及氮循环功能基因的改善。颤蚓可以提高饱和 VF-CWs 的净化功能，但这种策略强烈依赖于进水 C/N 比和颤蚓添加密度。
