Properties and fate and transport of persistent and mobile polar organic water pollutants: A review

The focus of this review is on the properties and transport and fate of polar organic pollutants in natural waters and engineered aquatic systems. We aim to list and discuss occurrence and treatment efficiencies, develop a new way to characterize mobile compounds by their basic properties, and provide a report of status and research needs on aquatic and multimedia models. The compound groups include selected per and polyfluoroalkyl substances (PFAS), pesticides, pharmaceuticals and personal care products (PPCPs), and other compounds. Octanol-water distribution coefficients (D) are calculated for PFAS by an expression including octanol-water partition coefficients (P) and ionization (Ka) constants, and by using Chemicalize.com for multiprotic PPCPs and other compounds. Log D ranges between 6 and 0 for PFAS and between 8 and 5 for PPCPs and pesticides. This is significantly lower than the ranges of P for nonpolar compounds such as polycyclic aromatic hydrocarbon (PAHs) and polychlorinated biphenyls (PCBs). Many pharmaceuticals and potential endocrine disruptors can be removed effectively in source, finished and distribution supply water through sorption, chemical oxidation, photolysis, and biodegradation. Sediment core profiles of polar organics may not reflect the chronology of their production and use, due to post-depositional mobility of the relatively water-soluble compounds. A novel approach for identifying mobile compounds is developed using sediment records extending downcore past authorization or initiation dates for the compounds. We find that an area limited by log water solubility mu mol/L > 4.2 and log D <-0.8 approximately defines an area of mobile compounds here represented by perfluorobutane sulfonic acid (PFBS), perfluorohexanoic acid (PFHxA), aminomethyl phosphonic acid (AMPA) and atenolol. Models in the aquatic or multimedia phases have been developed for PFAS with a hydrodynamic model; for insecticides and fungicides using geographic information system (GIS) and fugacity equations; and for atrazine and pharmaceuticals, considering mass flow. Global models were proposed and tested for PFAS and diclofenac. Automated calibration, fugacity calculations under nonequilibrium conditions, and toxicity evaluations could improve existing and future models.

Automated summary

This review focuses on the properties and fate of polar organic pollutants in natural waters and engineered aquatic systems. It discusses the occurrence and treatment efficiencies of various compound groups, including PFAS, pesticides, PPCPs, and other compounds. The review also presents a new approach to characterizing mobile compounds based on their basic properties and provides insights into the current status and research needs of aquatic and multimedia models. The findings suggest that many pharmaceuticals and endocrine disruptors can be effectively removed from water through sorption, chemical oxidation, photolysis, and biodegradation. Additionally, sediment core profiles may not accurately reflect the chronological production and use of polar organics due to post-depositional mobility of water-soluble compounds. The review proposes a novel method for identifying mobile compounds using sediment records, and highlights the development of models for PFAS, insecticides, fungicides, atrazine, and pharmaceuticals.