A polymeric hybrid particle or composition comprising of polymers, such as polystyrene or methylated polystyrenes with cyclic amines and their halogenated forms, and nanoparticles (NPs). The method for the preparation thereof and uses as nano-adsorbent, or a biocide, or a dual function combination of biocide and adsorbent for use in a fluid system for the purpose of purification or remediation are also disclosed.
