Pollution characteristics and fate of microfibers in the wastewater from textile dyeing wastewater treatment plant

Wastewater discharged from wastewater treatment plants (WWTPs) is suspected to be a significant contributor of microplastics (MPs) to the environment, and fiber is the main shape of MPs in wastewater effluent. A typical textile industry WWTP with 30,000 tons of daily treatment capacity was sampled for microfibers at different stages of the treatment process to ascertain at what stage in the treatment process the microfibers are being removed. The average abundance of microfibers was 334.1 (±24.3) items/litre in influent, and it reduced to 16.3 (±1.2) items/litre in the final effluent with a decrease of 95.1%. Despite this large reduction we calculated that this textile industry WWTP was releasing 4.89 × 10⁸ microfibers including microplastic fibers and non-microplastic fibers into the receiving water every day. This study showed that a modest amount of microplastics being released per litre of effluent could result in significant amounts of fibers entering the environment, despite the fact that efficient removal rates of microplastic fibers and non-microplastic fibers were achieved by this modern treatment plant when dealing with such a large volume of effluent. The fate of fibers is described during the textile industry wastewater treatment process.