Constructed wetlands (CWs) integrated with sulfur autotrophic denitrification to stimulate high-rate nitrogen removal from carbon-limited wastewater holds particular application prospect due to no excessive carbon source addition, high efficiency, and good stability. In this study, we conducted elemental sulfur-based constructed wetland (SCW) and traditional constructed wetland (CW) under different C/N (2, 1, and 0.5) to explore the feasibility and mechanisms for nitrogen removal from low C/N wastewater. Compared with CW, SCW was demonstrated more robust in nitrogen removal in the case of low C/N influent. When the influent C/N control was at 0.5, SCW observed total nitrogen (TN) and nitrate removal efficiency of 69.36 ± 3.96% and 81.71 ± 3.96%, with the corresponding removal rate of 1.18 ± 0.66 and 1.70 ± 0.92 g-N·m^–2·d^–1, which were 2.11 and 10.03 times of CW, respectively. The nitrate removal rate constant k in the SCW was 1.05, 3.83, and 10.33 times higher than the CW with C/N of 2, 1 and 0.5. Furthermore, 14.40, 54.51, and 79.82% of nitrogen were removed by the sulfur autotrophic denitrification (SAD) in SCW, which also contributed 43.89, 73.68, and 71.70% of sulfate production. Moreover, the combined system of CW-SCW is proved be an efficient operation mode for simultaneously removing total ammonia nitrogen (TAN) and nitrate. In the SCW, the richness of the microbial community was improved and sulfur-oxidizing genera (e.g. Thiobacillus, Sulfurimonas) was selectively enriched, which affect the performance the elemental sulfur-based denitrification process. The nitrate reduction pathway was overwhelmed by denitrification and the dissimilatory nitrate reduction process. These findings offer elemental sulfur-based autotrophic denitrification constructed wetland has excellent potential to enhance nitrogen removal from carbon-limited wastewater.

人工湿地（CWs）与硫自养反硝化相结合，以促进碳限制废水中的高速脱氮，由于无需过量添加碳源、效率高、稳定性好，具有特殊的应用前景。在这项研究中，我们在不同 C/N（2、1 和 0.5）下进行了基于元素硫的人工湿地（SCW）和传统人工湿地（CW），以探索低 C/N 废水脱氮的可行性和机制. 与 CW 相比，在低 C/N 进水的情况下，SCW 被证明在脱氮方面更稳健。当进水 C/N 控制在 0.5 时，SCW 观察到的总氮 (TN) 和硝酸盐去除效率分别为 69.36 ± 3.96% 和 81.71 ± 3.96%，相应的去除率为 1.18 ± 0.66 和 1.70 ± 0.92 gN·m ^{– 2个}·d ^–1，分别是CW的2.11和10.03倍。SCW 中的硝酸盐去除速率常数k比 C/N 为 2、1 和 0.5 的 CW 高 1.05、3.83 和 10.33 倍。此外，SCW 中的硫自养反硝化 (SAD) 去除了 14.40、54.51 和 79.82% 的氮，这也贡献了 43.89、73.68 和 71.70% 的硫酸盐产量。此外，CW-SCW组合系统被证明是同时去除总氨氮（TAN）和硝酸盐的有效运行模式。在 SCW 中，微生物群落的丰富度得到改善，硫氧化属（例如硫杆菌属、硫磺单胞菌属）) 被选择性富集，这会影响元素硫基反硝化过程的性能。硝酸盐还原途径被反硝化作用和异化硝酸盐还原过程所淹没。这些发现表明，基于元素硫的自养反硝化人工湿地具有极好的潜力，可以提高碳限制废水中的氮去除率。