Novel electrochemical reactor for accelerated uranium mineralization: Enabling continuous and rapid uranium wastewater treatment

The electrochemical conversion of uranyl ions in wastewater into stable synthetic minerals presents a promising strategy for mitigating reoxidation and migration risks. This technique utilizes specialized electrodes to enable uranium lattice doping mineralization under ambient conditions. Nevertheless, the practical implementation of continuous mineralization for uranium wastewater treatment is significantly hindered by the lack of scalable equipment capable of transitioning laboratory-scale shake-flask experiments into practical industrial applications. To address this limitation, we developed two distinct electrochemical mineralization reactor configurations: a linear reactor (LR) and an annular reactor (AR), both designed for rapid batch-mode treatment. These systems employed iron-graphite electrode pairs and were systematically evaluated for uranium removal efficiency, energy consumption, and product stability under varying electrode quantities, arrangements, and flow regimes. Compared with the LR reactor, the AR reactor, incorporating a composite cross-electrode design, demonstrated superior performance with a 97 % reduction in energy consumption and a 75 % decrease in iron usage. Furthermore, the AR reactor achieved a uranium removal efficiency exceeding 98.5 %, with 84.5 % of the uranium stabilized in a mineralized form, at an energy consumption of 56.56 kWh/kg U. Parameter optimization confirmed the suitability of AR reactor for large-scale, energy-efficient uranium immobilization, promoting the practical application of sustainable mineralization technology.