Adsorption of perfluoroalkyl and polyfluoroalkyl substances (PFASs) from aqueous solution - A review.

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) have gained increasingly global attention in recent years. Due to their unique amphiphilic properties and stability, PFASs are recognized as highly persistent, toxic, and environmentally bioaccumulative. Among several physicochemical technologies, adsorption has been extensively used and proved to be an effective method for removing PFASs from aqueous environment. In this review article, the technical feasibility of the use of different adsorbents, such as activated carbon, ion exchange resins, minerals, molecularly imprinted polymer (MIP), carbon nanotubes (CNTs), and a wide range of potentially low-cost biosorbents, for PFASs removal from water or wastewater is critically reviewed. The evaluation and comparison of their PFASs sorption behavior in terms of kinetics and isotherms is presented. The mechanisms involved in PFASs adsorption processes, such as diffusion, electrostatic interaction, hydrophobic interaction, ion exchange and hydrogen bond, are discussed. The effects of the parameters variability on sorption process are highlighted. Based on the literature reviewed, a few recommendations for future research on PFASs adsorption are also elaborated. Capsule: The adsorption behavior and mechanisms of perfluoroalkyl and polyfluoroalkyl substances (PFASs) on various adsorbents are reviewed.

Isolation and characterization of polycyclic aromatic hydrocarbon-degrading Mycobacterium isolates from soil.

Bioremediation of soils contaminated with wood preservatives containing polycyclic aromatic hydrocarbons (PAHs) is desired because of their toxic, mutagenic, and carcinogenic properties. Creosote wood preservative-contaminated soils at the Champion International Superfund Site in Libby, Montana currently undergo bioremediation in a prepared-bed land treatment unit (LTU) process. Microbes isolated from these LTU soils rapidly mineralized the (14)C-labeled PAH pyrene in the LTU soil. Gram staining, electron microscopy, and 16S rDNA-sequencing revealed that three of these bacteria, JLS, KMS, and MCS, were Mycobacterium strains. The phylogeny of the 16S rDNA showed that they were distinct from other Mycobacterium isolates with PAH-degrading activities. Catalase and superoxide dismutase (SOD) isozyme profiles confirmed that each isolate was distinct from each other and from the PAH-degrading mycobacterium, Mycobacterium vanbaalenii sp. nov, isolated from a petroleum-contaminated soil. We find that dioxygenase genes nidA and nidB are present in each of the Libby Mycobacterium isolates and are adjacent to each other in the sequence nidB-nidA, an order that is unique to the PAH-degrading mycobacteria.

Controlled ovulation in the marmoset monkey (Callithrix jacchus) with human chorionic gonadotropin following prostaglandin-induced luteal regression.

Controlled induction of ovulation in the marmoset monkey was attempted with a single injection of human chorionic gonadotropin (hCG; 50 IU) given on day 7 after prostaglandin-induced luteal regression. Animals given hCG (n = 12) ovulated within a 2-day period (days 9 and 10 after prostaglandin) compared with a 4-day period (days 9 to 12) in the control group (n = 12). The mean interval to ovulation was similar in both groups. There was no difference in the timing of the preovulatory estradiol (E2) peak between groups, although E2 levels on the day of hCG injection were lower than in controls on the day of the onset of the luteinizing hormone surge. All animals given hCG ovulated and 11 of 12 became pregnant. Ten of 11 embryos recovered surgically from six of these animals were normal blastocysts; 5 of the remaining 6 animals carried pregnancies to term. The results are of practical importance for experiments involving follicular and oocyte maturation and the collection and transfer of embryos.