Treatment of polluted river sediment by electrochemical oxidation: Changes of hydrophilicity and acute cytotoxicity of dissolved organic matter

Wang Lu; Nan Chen; Chuanping Feng; Yang Deng; Jing Zhang; Fangxin Chen

doi:10.1016/j.chemosphere.2019.125283

Treatment of polluted river sediment by electrochemical oxidation: Changes of hydrophilicity and acute cytotoxicity of dissolved organic matter

Chemosphere. 2020 Mar:243:125283. doi: 10.1016/j.chemosphere.2019.125283. Epub 2019 Nov 19.

Authors

Wang Lu¹, Nan Chen², Chuanping Feng¹, Yang Deng¹, Jing Zhang¹, Fangxin Chen¹

Affiliations

¹ School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, China.
² School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, China. Electronic address: chennan@cugb.edu.cn.

PMID: 31760292
DOI: 10.1016/j.chemosphere.2019.125283

Abstract

River sediment is the main internal pollution source of water body. This study evaluated the feasibility of electrochemical oxidation (EO) for polluted river sediment treatment. The hydrophilic and acute cytotoxicity (ACT) of dissolved organic matter (DOM) during electrolysis were mainly investigated. Meanwhile, the behavior of sediment evolution was also characterized. The results showed that the EO process was feasible for the treatment of polluted river sediment. The COD removal efficiency of polluted river sediment can achieve to 40.1% when the current density was 50 mA cm^-2 with the chloride ion of 3000 mg L^-1 and the initial pH of 8.5. The hydrophilicity of sediment DOM decreased with the decreasing molecule weight of humic-like substances, polar groups and the formation of aromatic aldehydes such as benzaldehyde. In this process, The ACT of sediment DOM can be reduced by the removal of aromatic compounds. In the process of electrolysis, the sediment particles were smaller than before, the dehydration was enhanced, and the crystal type tended to be stable, which was conducive to the utilization of resources. Therefore, EO method is a feasible alternative for the treatment of polluted river sediment.

Keywords: Acute cytotoxicity; Dissolved organic matter; Electrochemical oxidation; Hydrophilicity; Pollution load reduction.

MeSH terms

Electrolysis
Environmental Restoration and Remediation / methods*
Geologic Sediments / chemistry*
Hydrophobic and Hydrophilic Interactions
Organic Chemicals
Oxidation-Reduction
Rivers / chemistry
Water Pollutants, Chemical / analysis*

Substances

Organic Chemicals
Water Pollutants, Chemical