Functionalized Clay Adsorbent Coating for Low-Cost PFAS Removal

The patent uses composite materials by combining attapulgite or sepiolite clay minerals with quaternary amine functional groups and mercapto surface coating agents. This creates a hybrid adsorbent that leverages the high surface area and porosity of the clay mineral structure alongside the selective binding capabilities of the organic functional groups, achieving superior PFAS removal efficiency compared to activated carbon while maintaining cost-effectiveness through the use of abundant natural clay resources.

The patent modifies the surface properties of attapulgite or sepiolite through chemical functionalization with quaternary amines and mercapto groups. This parameter change transforms the surface chemistry of the clay mineral, creating active sites with specific affinity for PFAS molecules. The functionalization process alters surface charge, hydrophobicity, and chemical reactivity parameters, enabling high-efficiency PFAS adsorption while utilizing low-cost natural clay materials.

The patent employs inexpensive attapulgite or sepiolite clay minerals as the base material for the adsorbent. These natural clay materials are abundant, low-cost alternatives to expensive anion exchange resins. The functionalized clay adsorbent achieves high PFAS removal efficiency comparable to anion exchange resins but at a fraction of the material cost, making it economically viable for widespread water treatment applications.

The patent transforms ordinary low-cost clay minerals into high-performance adsorbents through surface functionalization. By introducing quaternary amine and mercapto functional groups, the surface properties of the clay are modified to create strong affinity for PFAS anions. This parameter change in surface chemistry enables the cheap clay material to perform at the level of expensive specialized resins.