Valorization of ball-milled waste red mud into heterogeneous catalyst as effective peroxymonosulfate activator for tetracycline hydrochloride degradation

Qingyong Li; Guangtao Wei; Guangxiang Duan; Linye Zhang; Zhongmin Li; Feng Yan

doi:10.1016/j.jenvman.2022.116301

Valorization of ball-milled waste red mud into heterogeneous catalyst as effective peroxymonosulfate activator for tetracycline hydrochloride degradation

J Environ Manage. 2022 Dec 15:324:116301. doi: 10.1016/j.jenvman.2022.116301. Epub 2022 Sep 27.

Authors

Qingyong Li¹, Guangtao Wei², Guangxiang Duan³, Linye Zhang⁴, Zhongmin Li³, Feng Yan³

Affiliations

¹ School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, PR China; School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China.
² School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, PR China; Guangxi Key Laboratory of Processing for Non-ferrous Metallic and Featured Materials, Guangxi Zhuang Autonomous Region, Nanning, 530004, PR China. Electronic address: gtwei@foxmail.com.
³ School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, PR China.
⁴ School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, PR China; Guangxi Key Laboratory of Bio-refinery, Guangxi Zhuang Autonomous Region, Nanning, 530007, PR China. Electronic address: yezi@gxu.edu.cn.

PMID: 36179468
DOI: 10.1016/j.jenvman.2022.116301

Abstract

Red mud (RM), a kind of iron-rich industrial waste produced in the alumina production process, can be utilized as a potential iron-based material for the removal of refractory organic pollutants from wastewater in advanced oxidation processes (AOPs). In this work, high-iron RM (rich in iron) was activated in a ball mill and applied as an effective activator of peroxymonosulfate (PMS) for tetracycline hydrochloride (TC-HCl) degradation. Compared with that of unmilled RM (69.7%), the TC-HCl decomposition ratios of ball-milled RM (BM-RM) (72.2%-92.0%) were all improved in the presence of PMS. Systematic characterization suggested that ball milling could optimize the physicochemical properties of RM, such as increased surface area, increased oxygen vacancies, enhanced electrical conductivity, and increased exposure of Fe(II) sites, all of which could effectively improve RM for PMS activation to degrade TC-HCl. The quenching experiments and electron paramagnetic resonance technique revealed that ¹O₂ and SO₄·^- contributed dominantly to the TC-HCl degradation. Ultra performance liquid chromatography mass spectrometry analysis combined with density functional theory calculation revealed that the degradation pathways of TC-HCl were driven by hydroxylation, N-demethylation and dehydration in BM-RM/PMS system. Based on quantitative structure-activity relationship prediction using the Toxicity Estimation Software Tool software, the toxicity of almost all intermediates was significantly reduced. An obvious inhibition effect on TC-HCl was occurred in the presence of Cl^-, whereas the presences of NO₃^- and SO₄^2- had little effect. However, HCO₃^- improved TC-HCl removal efficiency. BM-RM had a wide working pH range (pH = 3-11) and showed good stability and reusability in use. Overall, this work not only offers a simple and promising approach to improve the catalytic activity of RM, but also opens new insights into the ball-milled RM as an effective PMS activator for wastewater treatment.

Keywords: Advanced oxidation process; Ball milling; Peroxymonosulfate; Red mud; Valorization.

MeSH terms

Catalysis
Iron / chemistry
Peroxides* / chemistry
Tetracycline*

Substances

peroxymonosulfate
Tetracycline
Peroxides
Iron