An environmentally friendly gradient treatment system of copper-containing wastewater by coupling thermally regenerative battery and electrodeposition cell

An environmentally friendly gradient treatment system of copper-containing wastewater by coupling thermally regenerative battery and electrodeposition cell was proposed to remove Cu2+ and simultaneously recover the resources of low-temperature waste heat and copper, showing a promising application in electroplating factories. The feasibility and the key influencing factors of the key part of the system (TRB-EC) were investigated. The results showed a relatively high Cu2+ removal efficiency in the coupled TRB-EC powered by the stack with eight-cell pairs. With the increase of cell pairs, the open-circuit voltage and the maximum power generation linearly increased, and the removal efficiency increased with a decreasing speed rate. An optimal cell pair of 12 induced the peak total removal efficiency (78.6%) of TRB-EC in this study, and the rest of Cu2+ could be expectedly removed by the microbiological system. The removal efficiency increased with the initial Cu2+ concentration in a certain range. With respect to copper recovery, a competitive high-concentration Cu2+ solution could be recovered from the copper-containing wastewater. The removal efficiency and the recovered Cu2+concentration were expected to be promoted by alleviating the ammonia crossover in further study.