A way out of the alkaline bauxite residue: Synthesizing micro-electrolysis composite material towards the synergistic fenton degradation of high-concentration organic wastewater

Chenglong Lu; Wei Sun; Tong Yue; Haisheng Han; Wen Yu; Anh V Nguyen; Li Wang

doi:10.1016/j.jhazmat.2020.123210

A way out of the alkaline bauxite residue: Synthesizing micro-electrolysis composite material towards the synergistic fenton degradation of high-concentration organic wastewater

J Hazard Mater. 2020 Dec 5:400:123210. doi: 10.1016/j.jhazmat.2020.123210. Epub 2020 Jun 17.

Authors

Chenglong Lu¹, Wei Sun¹, Tong Yue², Haisheng Han³, Wen Yu⁴, Anh V Nguyen⁵, Li Wang¹

Affiliations

¹ School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources, Central South University, Changsha 410083, China.
² School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources, Central South University, Changsha 410083, China. Electronic address: yuetong@csu.edu.cn.
³ School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources, Central South University, Changsha 410083, China. Electronic address: hanhai5086@csu.edu.cn.
⁴ Faculty of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China.
⁵ School of Chemical Engineering, University of Queensland, Brisbane, QLD 4072, Australia.

PMID: 32590131
DOI: 10.1016/j.jhazmat.2020.123210

Abstract

Over 150 million tons of high-alkaline bauxite residue was produced during the Bayer process of Bauxite smelting in the world annually, causing massive encroachment and irreversible pollution of soil. In this work, we proposed a new way out of bauxite residue, synthesizing a micro-electrolysis composite material (MECM) by carbothermal reduction of the bauxite residue towards the degradation of high-concentration organic wastewater. Batch experiments of organic compounds degradation were conducted to evaluate the performance of MECM with or without synergistic Fenton process. XRD and SEM-EDS analysis results indicated that a proper calcination temperature (1000℃) could facilitate the generation and growth of zero-valent iron (ZVI), thereby forming a large number of galvanic cells with carbon, which could efficiently break the azo bonds. Additionally, the micro-electrolysis reaction of MECM could provide lots of Fe(Ⅱ), which constituted the Fenton system with the additional H₂O₂. In Fenton system, the aromatic rings and alkyl chains were further degraded and mineralized, which reduced the chemical oxygen demand (COD) of methyl orange (MO) from 450 to 54 mg/L. Therefore, the combination of the micro-electrolysis and Fenton process provides a clean and efficient method for the treatment of organic wastewater, which is a promising way out for bauxite residue.

Keywords: Bauxite residue; Carbothermal reduction; Dye contaminants; Heterogeneous Fenton; Micro-electrolysis.

Publication types

Research Support, Non-U.S. Gov't