Double catholyte electrochemical approach for preparing ferrate-aluminum: a compound oxidant-coagulant for water purification

Article type: Research Article

Authors: Qu, Jiu-hui | Lei, Peng-ju | Liu, Hui-juan

Affiliations: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. E-mail: jhqu@ mail.rcees.ac.cn

Abstract: Ferrate is an excellent water treatment agent for its multi-functions in oxidation, disinfection, coagulation and adsorption, but its coagulation ability depends on its dosage and is after its oxidation. This paper focuses on preparing a new kind of ferrate combined with alum to enhance its coagulation function for water purification. An effective electrolysis reactor was designed and employed in the test. Some key parameters in the process of electrolysis concerning the preparation efficiency, such as the current density, temperature and alkalinity were also investigated. The proper conditions for ferrate-alum preparation were determined. In the condition of 5V given voltage, 6h electrolyzing interval, below 2% alum concentration (in weight), a combined liquid ferrate-alum products was successfully prepared, which contained 0.0294 mol/L FeO_4^2-, 0.0302 mol/L total soluble ferron with 2% Al_2O_3. There was no insoluble ferron produced by controlling an optimum electrochemical condition.

Keywords: combined ferrate-alum, electrochemical preparation, oxidation, coagulation

Journal: Journal of Environmental Sciences, vol. 14, no. 1, pp. 49-53, 2002