ABSTRACT
Natural nanoparticles are present in all environments, mainly in terrestrial and aquatic systems and produced from non-human, natural processes such as microbial behaviour, weathering and chemical reactions. Natural adsorption has received increasing attention due to high efficiency, environmental friendliness, low cost, easy operation and insensitivity to toxic substances and the possibility of the materials recycling. New hybrid clay adsorbent based on kaolinite clay and papaya seeds with improved cation exchange capacity (CEC), rate of heavy metal ion uptake and adsorption capacity for heavy metal ions have been reported. Organically modified clay minerals have become essential for the development of polymer nanocomposites. Nano-biomaterials have an increased number of atoms and crystal grains at their surface and possesses a higher surface area to volume ratio than conventional microscale biomaterials. Artificial biomaterials are used as bone substitutes in biominesis-inspired approaches to produce nanocrystallites of calcium phosphate salts with natural polymers like collagen.
