Nitrogen discharged from mariculture industry leads to adjacent aquatic pollution. This study utilized an electrochemically assisted submerged fixed bed bioreactor (E-SFBBR) to treat carbon-limited saline mariculture wastewater and aimed to evaluate the performance and pathways of nitrogen removal by testing the effects of electrical stimulation and different current densities (CD). Electro-stimulation increased nitrogen removal performance of E-SFBBR from 1.1 to 2.2 g N m⁻² d⁻¹ to 3.0–3.4 g N m⁻² d⁻¹; CD of 0.10 mA cm⁻² resulted in the highest N removal rate. Results of water quality at different depths and the batch experiment revealed the N removal pathways in E-SFBBR: in the cathode area, nitrogen removal was mainly attributed to the processes of denitrification and dissimilatory nitrate reduction to ammonia; and in the anode area, nitrification and autotrophic denitrification driven by sulfur or iron contributed to nitrogen elimination. These findings provided a promising method for enhancing N removal from carbon-limited mariculture effluents.

从海水养殖业排放的氮会导致邻近的水生污染。这项研究利用电化学辅助的浸没式固定床生物反应器（E-SFBBR）处理含碳受限的海水养殖废水，旨在通过测试电刺激和不同电流密度（CD）的效果来评估脱氮性能和途径。电刺激使E-SFBBR的脱氮性能从1.1到2.2 g N m ^-2 d ^-1增加到3.0-3.4 g N m ^-2 d ^-1；CD为0.10 mA cm ^-2导致最高的氮去除率。不同深度水质的结果和分批实验揭示了E-SFBBR中的N去除途径：在阴极区，氮的去除主要归因于反硝化和硝化硝酸盐还原为氨的过程。在阳极区域，由硫或铁驱动的硝化作用和自养反硝化作用有助于消除氮。这些发现为提高碳限制的海水养殖废水中的氮去除提供了一种有前途的方法。