Groundwater, essential for ecological stability and freshwater supply, faces escalating nitrate contamination. Traditional biological methods struggle with organic carbon scarcity and low temperatures, leading to an urgent need to explore efficient approaches for groundwater remediation. In this work, we proposed an inorganic bioelectric system designed to confront these challenges. At 10 and 4 °C, the system achieved total nitrogen (TN) removal efficiencies of 95.4 ± 2.7% and 90.9 ± 1.9% at 2 h hydraulic retention time (HRT), while maximum TN removal rates were recorded as 206.0 ± 6.3 and 178.3 ± 9.4 g N·m