Tio2 and carbon nanotubes composites modify capacitive deionization anodes to improve the dechlorination efficiency in desulfurization wastewater
Shuangchen Ma, Chang Liu, Yongyi Xu, Yu Tan, Dingchang Yang, Feng Wang, Lan Ma
Abstract
Abstract A new capacitive deionization (CDI) technology was used to remove Cl− from desulfurization wastewater. TiO2 and carbon nanotubes (CNTs) were combined with N-methyl pyrrolidone (NMP) to form composites by a solvothermal method in which it is coated onto the CDI anode to improve dechlorination efficiency (DE). The morphology, surface area, wettability, crystal structure and chemical composition of the TiO2/CNTs were characterized. They showed good hydrophilicity (contact angle: 85.9°), high specific surface area (96.68 m²/g) and high specific capacitance (87.6 F/g). The experimental results illustrated that the best DE was achieved by the composites (60%T/C) under 1.2 V with the maximum electrosorption capacity toward 6.5 mg/g, and the TiO2/CNTs composites had excellent stability. Adsorption kinetics analysis was explored and analyzed. Furthermore, TiO2/CNTs composites exhibited excellent DE in actual desulfurization wastewater. The catalysis and adsorption mechanisms of the TiO2/CNTs anode were discussed in detail. This study provides a new direction for the application of TiO2/CNTs composites as adsorption materials of CDI in the Cl− of desulfurization wastewater.