During natural and manmade disasters such as floods and chemical spills, hazardous chemicals can be mobilized in the environment and affect water and food sources. Practical and economically-feasible technologies are needed to reduce the bioavailability of these chemicals and the risk of potential exposures. To solve this problem, we have developed and characterized novel, broad-acting sorbents that can effectively bind hazardous chemicals in the environment to reduce exposures. Calcium montmorillonite clays were modified with L- carnitine and choline to increase the lipophilicity of clay surfaces. Calcium montmorillonite clays were also processed and activated with sulfuric acid to increase the surface area and porosity of the clay. These sorbents were tested as soil amendments to determine the safety of the sorbents for plants and ability of the sorbents to reduce translocation of chemicals to plants. In this study we characterized sorbent-chemical relationships using in vitro, in vivo, and in silico methods. Isothermal analyses indicated parent, modified, and processed calcium montmorillonite clays were highly effective sorbents of a variety of environmental chemicals with different chemical properties. Acid-processed clay (APM) had high capacity and affinity for the lipophilic chemical dieldrin and could significantly reduce dieldrin bioavailability from soil. The parent calcium montmorillonite clay significantly protected Hydra vulgaris from aminomethylphosphonic acid (AMPA) toxicity and reduced AMPA residues in corn sprouts. Nutrient-modified clays were effective sorbents of the amphiphilic compounds perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) based on isothermal results, soil and plant studies, and molecular dynamics simulations. Our results indicate that, upon further investigation, application of optimized sorbents to soil and added in higher levels after disasters can reduce chemical bioavailability and exposures to environmental chemicals.
