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 multi-protic 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 µmol/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.