title: A zero-liquid-discharge scheme for vanadium extraction process by electrodialysis-based technology.
abstract: The sharp increase of demand for vanadium makes the treatment of the wastewater generated from its extraction process become an urgent problem. In this study, a hybrid process coupling the electrodialysis with the cooling crystallization is put forward for upgrading the conventional vanadium extraction process to zero discharge. Accordingly, the objective of this work lies in evaluating the feasibility of the proposed scheme on the basis of a systematic study on the influences of membrane types and operating parameters on the electrodialysis performance. The results indicate that the relative importance of osmosis and electro-osmosis to overall water transport is closely related to the applied current density. The increase in the applied current density and the decrease in the mole ratio of water and salt flux will contribute to the concentration degree. Moreover, it is worth noting that a relatively large concentration ratio can result in the remarkable decrease of current efficiency and increase of energy consumption. In general, the reclamation scheme can easily achieve the recovered water with relatively low salt content and the highly concentrated Na2SO4 solution (e.g., 300 g/L) for producing high-purity sodium sulphate crystals.
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, China; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China. Electronic address: wangmeng@ouc.edu.cn.
authors.forename: Meng
authors.initials: M
authors.lastname: Wang
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, China; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Xing
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, China; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Yu-Xiang
authors.initials: YX
authors.lastname: Jia
authors.affiliation: Beijing Unisplendour Empyreal Environmental Engineering Technology Co. Ltd., Beijing 100083, China.
authors.forename: Qing-Chun
authors.initials: QC
authors.lastname: Ren
keywords: Concentration ratio; Industrial saline water; Vanadium extraction; Water transport; Zero-liquid-discharge