Issue 9, 2018

Cyto- and geno-toxicity of 1,4-dioxane and its transformation products during ultraviolet-driven advanced oxidation processes

Abstract

Ultraviolet-driven advanced oxidation processes (UV/AOPs) are integral steps in water reuse treatment trains. The toxicity of trace organic transformation products during a UV/AOP is critical to its implementation. This study examined the cyto- and geno-toxicity of transformation products of 1,4-dioxane (1,4-D), a trace organic contaminant commonly found in secondary wastewater, in extracts using the CellSensor p53RE-bla HCt-116 cell assay, following UV photolysis at 254 nm with three oxidants, hydrogen peroxide (H2O2), persulfate (S2O82−) and monochloramine (NH2Cl). 1,4-D was transformed into six major oxidation by-products, including ethylene glycol diformate, formaldehyde, glycolaldehyde, glycolic acid, formic acid, and methoxyacetic acid. Formaldehyde and glycolaldehyde were the most geno- and cyto-toxic, while 1,4-D had weak genotoxicity and no cytotoxicity. The order for cytotoxicity on the basis of EC50 values is as follows: glycolaldehyde > formaldehyde > formic acid > glycolic acid > 1,4-D > ethylene glycol diformate ≈ methoxyacetic acid, with glycolaldehyde and formaldehyde showing high genotoxicity. With the three UV/AOPs, genotoxicity expressed as mitomycin equivalency quotient (MEQ) increased significantly by 10 to 100 fold with a UV dosage of 720 mJ cm−2, mainly due to the formation of glycolaldehyde. UV/S2O82− reduced the MEQ with an increased UV dosage of 1440 mJ cm−2, due to the transformation of toxic aldehydes to less toxic organic acids. In contrast, UV/H2O2 increased the MEQ with UV dosage, resulting from the accumulation of aldehyde products. UV/NH2Cl showed the lowest MEQ due to its slow removal of 1,4-D. This study suggests that oxidants and UV dosage can affect the toxicological responses of treatments for recycled water.

Graphical abstract: Cyto- and geno-toxicity of 1,4-dioxane and its transformation products during ultraviolet-driven advanced oxidation processes

Supplementary files

Article information

Article type
Communication
Submitted
18 Feb 2018
Accepted
24 Mai 2018
First published
31 Mai 2018

Environ. Sci.: Water Res. Technol., 2018,4, 1213-1218

Author version available

Cyto- and geno-toxicity of 1,4-dioxane and its transformation products during ultraviolet-driven advanced oxidation processes

W. Li, E. Xu, D. Schlenk and H. Liu, Environ. Sci.: Water Res. Technol., 2018, 4, 1213 DOI: 10.1039/C8EW00107C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements