CHANGZHOU – For the first time ever, researchers from China have measured the impact that textile dyeing wastewater treatment processes have on the removal of pollutant mircofibres which have shed from textiles. They found the use of modern wastewater treatment processes removed 95 per cent of microfibres. However, they suggested that, due to the huge volume of effluent involved, even a modest amount of microfibres being released per litre of effluent could result in significant amounts of fibres entering the environment.
The researchers selected a standard textile industry WWTP (waste water treatment plant) which received the production wastewater of 33 printing and dyeing enterprises, between them treating an average of 30,000 tons per day of wastewater which is discharged from the WWTP.
They compared influent and effluent to measure the impact of modern treatment processes on the amount and type of microfibres contained in wastewater. They found the average amount of microfibres was 334.1 (±24.3) items per litre of influent, and that this reduced to 16.3 (±1.2) items per litre in the final effluent – a decrease of 95.1 per cent.
“The study showed textile dyeing WWTP had an effective removal on pollutants including microfibres in wastewater,” says the paper. The study also indicated that the abundance of microfibres reduced at varying rates across different stages of treatment, which “could provide a reference for the improvement of sewage treatment facilities in the future.”
Added the researchers: “Despite this large reduction we calculated that this textile industry WWTP was releasing 4.89 × 108 of microfibres including microplastic fibres (eg polyester) and non-microplastic fibres (eg cotton) into the receiving water every day. This study showed that despite the removal rates of microplastic fibres and non-microplastic fibres achieved by this modern treatment plant, when dealing with such a large volume of effluent even a modest amount of microplastics being released per litre of effluent could result in significant amounts of fibres entering the environment.”
In the aquatic environment, microfibres can absorb a variety of pollutants that are widely distributed in marine and freshwater ecosystems, such as PAHs and PCBs which has been proved to have toxic effects on fish. Because of their small size they are easily ingested by organisms. These toxic pollutants may eventually enter into food chain if the contaminated plastic residues are ingested by fish, aquatic invertebrates, and other wildlife.
Full paper: https://bit.ly/2Twjnlf