Fluorescence visualization of CO2-responsive phase transfer materials targeting at the heterogeneous interfacial reactions in advanced oxidation of naphthenic acid in wastewater

Hongwei Ren; Ruoyao Zhang; Yi Zheng; Yize Liu; Qiuya Zhang; Juan Zhang; Chunmao Chen; Erhong Duan

doi:10.1016/j.scitotenv.2024.173235

Fluorescence visualization of CO₂-responsive phase transfer materials targeting at the heterogeneous interfacial reactions in advanced oxidation of naphthenic acid in wastewater

Sci Total Environ. 2024 Jul 10:933:173235. doi: 10.1016/j.scitotenv.2024.173235. Epub 2024 May 14.

Authors

Hongwei Ren¹, Ruoyao Zhang², Yi Zheng³, Yize Liu³, Qiuya Zhang³, Juan Zhang², Chunmao Chen⁴, Erhong Duan⁵

Affiliations

¹ School of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang, Hebei 050018, PR China; Pollution Prevention Biotechnology Laboratory of Hebei Province, Shijiazhuang, Hebei 050018, PR China.
² School of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang, Hebei 050018, PR China.
³ School of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang, Hebei 050018, PR China.
⁴ State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, PR China.
⁵ School of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang, Hebei 050018, PR China; Pollution Prevention Biotechnology Laboratory of Hebei Province, Shijiazhuang, Hebei 050018, PR China. Electronic address: duan_eh@163.com.

PMID: 38750751
DOI: 10.1016/j.scitotenv.2024.173235

Abstract

Treatment of naphthenic acids (NAs) in wastewater is necessary due to its high toxicity and difficult degradation. In the heterogeneous Fenton-like advanced oxidation of organic pollutant system, the insufficient accessibility of oxidizing agent and NAs greatly hamper the reaction efficiency. CO₂-responsive phase transfer materials derived from polyethylene glycol (PEG)-based deep eutectic solvents were specific targeted at the immiscible-binary phase system. The NAs oxidative degradation process was optimized including the kinds of catalyst (Molecular weight of PEG, constitute of DESs, and dosage.), temperature, flow rate of CO₂, et al. With the help of fluorescence properties of catalyst, the hydrophilic-hydrophobic interaction was visual-monitored and further studied. The amphipathic property of PEG-200/Sodium persulfate/Polyether amine 230 (PEA230) greatly reduced the aqueous/organic phase transfer barrier between sodium persulfate and NAs (up to 84 %), thus accreting oxidation rate. The surface tension decreased from 35.364 mN/m to 28.595 mN/m. To control the reaction rate, the CO₂ respond structure of amido played an important role. In addition, the interfacial transfer intermediates and oxidation pathways were also explored by nuclear magnetic resonance, flourier transform infrared spectroscopy, surface tension, and radical inhibition experiments. The mechanism of advanced oxidation of NAs catalyzed by CO₂-responsive phase transfer catalyst was proposed, which would made up for the deficiency of the system theory of heterogeneous chemical oxidation of organic pollutants.

Keywords: CO(2)-responsive phase transfer; Green chemistry; Na(2)S(2)O(8).