A review on technologies for the removal of per- and polyfluoroalkyl substances (PFASs) in aquatic environments

Abstract

Per- and polyfluoroalkyl substances (PFASs), emerging contaminants with significant biotoxicity, are widely present in aquatic environments. This review analyzes PFAS removal technologies (including adsorption, oxidation techniques—electrochemical, photocatalytic, and sonolytic—biodegradation, and membrane separation), examining their mechanisms, effectiveness, advantages, disadvantages, and applicability. Adsorption remains the most prevalent method, effectively removing PFASs across various concentration levels. However, limitations include long adsorption cycle, difficulty in removing short-chain PFASs, and less-than-ideal regeneration capabilities, which drives ongoing exploration of novel adsorbent materials. Electrochemical, photocatalytic, and sonolytic degradation technologies offer high removal efficiency, short reaction times, the ability to degrade short-chain PFASs, and mineralization potential. Achieving complete mineralization, however, requires stringent reaction conditions, and high energy demands lead to significant operational costs. For biodegradation technology, the search for microorganisms with high PFAS mineralization capabilities and plant species with high PFAS accumulation capacity remains crucial. Consequently, developing low-cost, highly efficient, and widely applicable PFAS removal technologies is an urgent priority. Combining these technologies with other removal methods may be an important direction for future development.