A review of emerging PFAS contaminants: sources, fate, health risks, and a comprehensive assortment of recent sorbents for PFAS treatment by evaluating their mechanism

Per- and polyfluoroalkyl substances (PFASs) have highly complex behavior in the environment and are environmentally persistent. Exposure to PFASs causes cancer, liver toxicity, effect on the thyroid hormones, and also brings risks for the animal's health. PFASs are separated into two categories: non-polymers and polymers, and most parts of the study of PFASs focus on non-polymers because they are more found in the environments. Urban water cycles such as drinking water, surface water, groundwater, and wastewater have been faced with the occurrence of PFASs, and PFOS and PFOA are the most detected PFASs. Various methods have been applied to remove PFASs which are divided into two main categories: separation and destruction. The PFASs destruction is still challenging in practice because of the powerful C-F bond and has only been utilized at the laboratory and small scale. Therefore, sorption is an eco-friendly and cost-effective technique with high efficacy that is commonly applied to eliminate PFASs from wastewater. In this review, most important sorption techniques used to remove long- and short-chain PFASs are collected such as powdered or granular activated carbons, carbon nanotubes, biochar, polysaccharide-based adsorbents, ion exchange resins, and minerals. Additionally, the possible mechanisms of PFASs sorption on various adsorbents are summarized, and different interactions such as electrostatic and hydrophobic interactions are reviewed. However, coexisting of inorganic anions and cations, natural organic matters, and other organic contaminants that generally exist in wastewater can affect the sorption of PFASs. Moreover, environmentally friendly and economical ways for the regeneration of adsorbents were summarized. Although this process needs more research and evaluation.

Automated summary

PFASs exhibit complex behavior and environmental persistence, causing health issues upon exposure. Non-polymer PFASs are mainly studied, impacting urban water cycles. Sorption is commonly used to remove PFASs, facing challenges due to their strong bond.