PFAS in textile wastewater: An integrated scenario analysis for interventions prioritization to reduce environmental risk

Abstract

Per- and polyfluoroalkyl substances (PFAS) are used in several industrial applications, such as in textile manufacturing, and are known as “forever chemicals” due to their spread, stability and (eco-)toxicity, gaining increasing concern. To avoid PFAS spread in the environment, reducing the environmental risk on receiving surface water, prevention and removal strategies should be implemented at multiple levels, comprising both textile factories and municipal wastewater treatment plants (WWTP). This study presents an integrated scenario analysis to compare and prioritize prevention and removal strategies based on their potential in risk minimization. Field monitoring campaigns, lab- and pilot-scale experiments on two established removal processes (pressure-driven membrane separation, adsorption on activated carbon) were combined, and environmental risk was assessed due to a mixture of 15 PFAS. About prevention, substitution of long-chain PFAS with short-chain PFAS were considered, as well as the reduction of PFAS used in textile processing. The proposed approach was applied in a textile district in northern Italy without PFAS spikes in the tested wastewaters. This approach has proven to be beneficial in determining the optimal combination of actions to be implemented across different levels of the industrial district (including textile factories and/or municipal WWTP). This methodology provides a clear indication of the environmental advantages, specifically in minimizing risks, resulting from the implementation of diverse PFAS reduction strategies. Compared to the current scenario, resulting in an unacceptable risk (risk quotient, RQ=2.2), the risk can be reduced below the acceptable threshold (RQ=0.9) by the combination of (i) PFAS reduction/replacement in textile processing, (ii) treatment of wastewater discharged by textile factories through membrane separation prior to the discharge in the sewer, and (ii) WWTP upgrade through an activated carbon adsorption downstream the ozonation step.