LAUSR

In this study, the process optimization of industrial waste salts separated into acid/base for the realization of resource utilization was evaluated using bipolar membrane electrodialysis. Initial salt concentration and current density were believed to be the main factors for recycling performance, and then central composite design (CCD) of response surface methodology (RSM) was conducted to optimize the operating parameters regarding the generation of acid/base. The analyses of RSM revealed that the influencing degree of initial salt concentration on the acid/base generation was more significant than that of current density. Initial salt concentration of 240 g/L and current density of 36.54 mA/cm2 were obtained as optimized conditions by RSM. Under optimum conditions, acid concentration of 1.89 mol/L and base concentration of 2.28 mol/L were predicted which had good agreement with experimental results, the corresponding current efficiencies were 66.73% for acid, and 71.28% for base, respectively. Meanwhile, the energy consumptions were calculated as 6.21 kWh/kg for acid and 5.03 kWh/kg for base. Furthermore, the effects of total organic carbon (TOC) concentration on the generation of acid/base and energy consumption were also investigated. The results revealed that the TOC concentration of 0.68 g/L was benefited for the generation of acid/base and reduction of energy consumption.