Contaminants in coastal wastewater are prone to induce red tide in sea water and cannot be removed with traditional biological and ecological treatment methods due to salt stress. In this study, constructed wetlands (CWs) were used to remove contaminants from coastal wastewater and the optimal conditions of CWs including C/N ratio and initial contaminant concentration in influents were determined. CW-0.5 (constructed wetlands with a salinity of 0.5‰) was the optimal CW treatment system and realized higher removal efficiencies (75.29% of TN and 76.33% of COD) at 150 mg L⁻¹ COD and 30 mg L⁻¹ in influents after 3 day HRT. After adding 20 mg L⁻¹ ferrous ions, the COD and TN removal efficiencies were respectively increased by 8.67% and 3.71%. According to the high-throughput sequencing results, Thioalkalivibrio was identified to promote denitrification. Under salt stress conditions, ferrous ions optimized the microbial community structure and promoted the enrichment of specific bacteria for wastewater treatments. The optimal CW in this study is a promising process for the efficient nitrogen removal from coastal wastewater.

中文翻译：

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添加亚铁离子改善了人工湿地中低C / N沿海废水的污染物去除性能

沿海废水中的污染物易于在海水中诱发赤潮，并且由于盐胁迫而无法通过传统的生物和生态处理方法去除。在这项研究中，使用人工湿地（CW）去除沿海废水中的污染物，并确定了CW的最佳条件，包括C / N比和进水的初始污染物浓度。CW-0.5（盐度为0.5‰的人工湿地）是最佳的CW处理系统，在150 mg L ^-1 COD和30 mg L ^-1的进水中实现了更高的去除效率（TN的75.29％和COD的76.33％）。HRT 3天后。加入20 mg L ^-1后亚铁离子的化学需氧量和总氮去除效率分别提高了8.67％和3.71％。根据高通量测序结果，确定硫代碱度弧菌可促进反硝化作用。在盐胁迫条件下，亚铁离子优化了微生物群落结构，并促进了用于废水处理的特定细菌的富集。这项研究中的最佳连续波是从沿海废水中有效脱氮的有前途的过程。