AMHERST, Mass. — Textile wastewater treatment practices inadvertently produce toxic byproducts—including chloroform and bromoform—at alarming levels that pose a clear occupational health hazard and lead to unknown environmental effects downstream. University of Massachusetts Amherst researchers have found.
“As we did our research, we started to uncover that, in industrially relevant concentrations, a huge amount of byproducts are formed,” says Sean McBeath , assistant professor in the Riccio College of Engineering at UMass Amherst. “The focus of the paper really was the occupational hazards from formed byproducts on the people working in these factories.”
The textile industry accounts for as much as 20% of the world’s wastewater, according to the World Bank. Previous research has shown that textile wastewater can be harmful to the environment, crop production and human health. In an attempt to treat wastewater before it enters the environment, companies have turned to electrochemical methods, essentially zapping the water with electricity to break down the dyes.
“The electrodes interact with things in the water,” explains McBeath. “So, for example, textile dyes: Electrodes will exchange electrons and break these organic pollutants down further and further, hopefully until they’re completely degraded down to….essentially, CO 2 .”
As part of this procedure, companies have been adding sodium chloride, or regular table salt. This increases conductivity in water so that treatment requires less energy to break down the dyes and makes the waste degrade faster.
“But we were concerned,” says McBeath. “You add salt. It brings down your energy costs, and it increases your degradation performance, so your treatment performance goes up. But the side that no one’s looking at now is, at what cost does it do that?”
McBeath’s research group, the Water, Wastewater and Electrochemical Technologies (WWET) Lab, typically studies drinking water treatment. Their research in drinking water has shown that when chloride is present in these electrochemical reactions, reactive chlorine species are formed. These, in turn, can facilitate the production of unwanted and harmful byproducts (known as disinfection byproducts in the drinking water treatment industry).
“There could be all sorts of human impacts to occupational health impacts, as well as downstream environmental health impacts,” he adds.
In their study, McBeath and his team investigated both Azo dyes which represent 50% of the dyes in the market. They found chloride-based toxic byproducts at levels of hundreds of parts per billion. They also tested common textile dyes that contain bromine and found that textile wastewater treatment can generate bromoform at 526 ppb (parts per billion).
The U.S. does not set limits on these compounds in textile wastewater treatment, but the Environmental Protection Agency regulates these compounds in drinking water as a cumulative measure of multiple types of these compounds (referred to as trihalomethane species). This limit is set at 80 ppb.
McBeath said the concentrations they found in their study are alarming. “For Azo dyes, it’s three times higher than what we’re allowed to shower in or drink.” He also adds that, when bromine was present in dyes, this increased to greater than ten times the EPA regulatory limit.
The paper offered three mitigation options. First is using a different type of salt, like sodium sulfate instead of sodium chloride, that doesn’t generate the same harmful byproducts but is a slower process. Another option would be to use novel catalysts, which speed up the reaction, but are costly and generate some—though less—byproducts. And finally, a third option would be to continue business as usual practice but build in worker protections, such as proper ventilation in the textile factories.
“It all amounts to: how much money you have to include additional treatment, or how much time you have to slow down your reactions?” says McBeath. “It’s companies’ responsibilities to make sure that they’re not doing harm to their workers and to the downstream environment which might have impacts on aquatic life or even human health, ultimately, if these pollutants are somehow making it into water sources that people use.”
McBeath says that the next steps are to better understand possible pre-treatment steps that obviate the needs to leverage costs, treatment efficiency and safety hazards. He also adds that future research should investigate if other byproducts are generated in textile wastewater treatment processes.
“The textile industry seems a bit like the wild west,” he says. “Treatment can often not be pursued, and regulations can vary wildly from country to country. I think the role of my paper, however, is to help inform researchers and the public that, while electrochemical treatment is a highly efficient technology for textile dye waste, considerations need to be made towards the potential hazards of formed disinfection byproducts.”
The findings are published in the Journal of Hazardous Materials .
This research was led by Faye Kuszewski , a recent master’s graduate of UMass Amherst in the WWET Lab.
Journal of Hazardous Materials
Experimental study
Not applicable
Oxidation byproduct formation by electro-oxidation of textile dye wastewater: Occurrence, characterization and mitigation
1-Jun-2026
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.