Enhancement of cottonseed oil refining wastewater treatment by zero valent iron under sunlight irradiation and O2 bubbling

Chunzhen Fan; Suqing Wu; Xiangyong Zheng; Ke Bei; Shengbing He; Min Zhao

doi:10.1016/j.jcis.2022.01.171

Enhancement of cottonseed oil refining wastewater treatment by zero valent iron under sunlight irradiation and O₂ bubbling

J Colloid Interface Sci. 2022 Jun:615:124-132. doi: 10.1016/j.jcis.2022.01.171. Epub 2022 Jan 29.

Authors

Chunzhen Fan¹, Suqing Wu², Xiangyong Zheng², Ke Bei³, Shengbing He⁴, Min Zhao²

Affiliations

¹ National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Key Laboratory of Zhejiang Province for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Wenzhou 325000, PR China; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
² National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Key Laboratory of Zhejiang Province for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Wenzhou 325000, PR China.
³ National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Key Laboratory of Zhejiang Province for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Wenzhou 325000, PR China. Electronic address: beike@wzu.edu.cn.
⁴ School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China. Electronic address: heshengbing@sjtu.edu.cn.

PMID: 35124500
DOI: 10.1016/j.jcis.2022.01.171

Abstract

This study is the first to apply a zero-valent iron (ZVI) system in the treatment of cottonseed oil (CTO) refining wastewater. The results indicated that the ZVI system can effectively degrade and mineralize CTO in the wastewater, whereas sunlight irradiation and O₂ bubbling can considerably enhance CTO degradation, removing 93.5% of CTO and 69.0% of chemical oxygen demand within 180 min. In addition, a low concentration (0.1 mM) of SO₄^2- and Cl^- in the wastewater improved CTO degradation, whereas a high concentration (>1 mM) of these anions considerably inhibited the degradation process. However, NO₃^- at all concentrations hindered CTO degradation. Furthermore, OH and O₂^- were the main active species for CTO degradation in the ZVI system under dark conditions. However, in addition to these two species, photogenerated hole (h⁺) played a key role in CTO degradation under sunlight irradiation. This observation might be derived from the photocatalytic effect due to photoexcitation of the iron corrosion product, γ-FeOOH. Our findings show that the ZVI system assisted by sunlight irradiation and O₂ bubbling is feasible for CTO-refining wastewater treatment and can guide the real wastewater treatment project.

Keywords: Cottonseed oil refining wastewater; Iron corrosion product; Photocatalytic; Zero valent iron.

MeSH terms

Cottonseed Oil
Iron
Sunlight
Water Pollutants, Chemical*
Water Purification* / methods

Substances

Cottonseed Oil
Water Pollutants, Chemical
Iron