Low organic carbon-to-nitrogen ratio and existing sulfate (SO₄²⁻) in industrial wastewater limited nitrogen removal. Coupling SO₄²⁻ reduction with sulfide autotrophic denitrification provides a novel strategy. Herein, bioelectrochemical sulfate reduction was coupled with heterotrophic sulfate reduction to drive sulfide autotrophic denitrification. In this coupled system, total nitrogen (TN) removal efficiency was increased from ~25% to ~85% by inputting −45 mA electricity. With the help of supplying electrons to denitrification through SO₄²⁻ reduction, coulomb efficiency was improved to 61.5%. Also, bioelectrochemical sulfate reduction could improve sulfur recovery and thus increase TN removal efficiency. Furthermore, through tuning turnover numbers of SO₄²⁻, high TN removal efficiency can be obtained at various concentrations of SO₄²⁻. Moreover, main functional bacteria in this system were identified. Finally, ~75% TN removal efficiency was achieved with real wastewater in this system. Overall, this work offered a new approach for efficient nitrogen removal from industrial wastewater containing SO₄²⁻.

中文翻译：

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生物电化学硫酸盐还原增强含氨和硫酸盐工业废水脱氮

工业废水中的低有机碳氮比和现有的硫酸盐 (SO ₄ ^2- ) 限制了脱氮。SO ₄ ^2-还原与硫化物自养反硝化相结合提供了一种新策略。在此，生物电化学硫酸盐还原与异养硫酸盐还原相结合以驱动硫化物自养反硝化。在这个耦合系统中，通过输入 -45 mA 的电流，总氮 (TN) 去除效率从~25% 增加到~85%。借助 SO ₄ ²⁻向反硝化提供电子减少，库仑效率提高到 61.5%。此外，生物电化学硫酸盐还原可以提高硫回收率，从而提高 TN 去除效率。此外，通过调整SO ₄ ^{2- 的}转换数，可以在不同浓度的SO ₄ ^{2- 下}获得高TN 去除效率。此外，还鉴定了该系统中的主要功能细菌。最后，在该系统中使用真实废水实现了约 75% 的 TN 去除效率。总的来说，这项工作提供了一种从含有 SO ₄ ^{2- 的}工业废水中有效去除氮的新方法。