Comparative study of Fe(II)/sulfite, Fe(II)/PDS and Fe(II)/PMS for p-arsanilic acid treatment: Efficient organic arsenic degradation and contrasting total arsenic removal

Yuan Gao; Yun Luo; Zhao Pan; Zhu Zeng; Wenxia Fan; Jingyu Hu; Zhong Zhang; Jinxing Ma; Yang Zhou; Jun Ma

doi:10.1016/j.watres.2023.120967

Comparative study of Fe(II)/sulfite, Fe(II)/PDS and Fe(II)/PMS for p-arsanilic acid treatment: Efficient organic arsenic degradation and contrasting total arsenic removal

Water Res. 2024 Feb 1:249:120967. doi: 10.1016/j.watres.2023.120967. Epub 2023 Dec 3.

Authors

Yuan Gao¹, Yun Luo¹, Zhao Pan¹, Zhu Zeng², Wenxia Fan², Jingyu Hu¹, Zhong Zhang², Jinxing Ma², Yang Zhou³, Jun Ma⁴

Affiliations

¹ School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou, Guangdong 510006, China.
² Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China.
³ Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China. Electronic address: zhouyang@gdut.edu.cn.
⁴ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.

PMID: 38070343
DOI: 10.1016/j.watres.2023.120967

Abstract

As a widely used feed additives, p-arsanilic acid (p-AsA) frequently detected in the environment poses serious threats to aquatic ecology and water security due to its potential in releasing more toxic inorganic arsenic. In this work, the efficiency of Fe(II)/sulfite, Fe(II)/PDS and Fe(II)/PMS systems in p-AsA degradation and simultaneous arsenic removal was comparatively investigated for the first time. Efficient p-AsA abatement was achieved in theses Fe-based systems, while notable discrepancy in total arsenic removal was observed under identical acidic condition. By using chemical probing method, quenching experiments, isotopically labeled water experiments, p-AsA degradation was ascribed to the combined contribution of high-valent Fe(IV) and SO₄^•-in these Fe(II)-based system. In particular, the relative contribution of Fe(IV) and SO₄^•- in the Fe(II)/sulfite system was highly dependent on the molar ratio of [Fe(II)] and [sulfite]. Negligible arsenic removal was observed in the Fe(II)/sulfite and Fe(II)/PDS systems, while ∼80% arsenic was removed in the Fe(II)/PMS system under identical acidic condition. This interesting phenomenon was due to that ferric precipitation only occurred in the Fe(II)/PMS system. As(V) was further removed via adsorption onto the iron precipitate or the formation of ferric arsenate-sulfate compounds, which was confirmed by particle diameter measurements, fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Through tuning solution pH, complete removal of total arsenic could achieve in all three systems. Among these three Fe-based technologies, the hybrid oxidation-coagulation Fe(II)/PMS system demonstrated potential superiority for arsenic immobilization by not requiring pH adjustment for coagulation and facilitating the in-situ generation of ferric arsenate-sulfate compounds with comparably low solubility levels like scorodite. These findings would deepen the understanding of these three Fe-based Fenton-like technologies for decontamination in water treatment.

Keywords: Arsenic; Fe(II)/PDS; Fe(II)/PMS; Fe(II)/sulfite; P-arsanilic acid (p-AsA).

MeSH terms

Arsanilic Acid / chemistry
Arsenates / chemistry
Arsenic* / chemistry
Ferric Compounds / chemistry
Ferrous Compounds
Iron / chemistry
Oxidation-Reduction
Sulfates
Sulfites
Sulfur Oxides
Water Pollutants, Chemical* / chemistry

Substances

Arsenic
arsenic acid
Arsenates
Arsanilic Acid
Iron
Ferric Compounds
Sulfites
Sulfates
Sulfur Oxides
Ferrous Compounds
Water Pollutants, Chemical