Recent potential application of rice husk as an eco-friendly adsorbent for removal of heavy metals

Environmental contamination by heavy metals has continued to be a source of serious concerns to researchers because of its far-reaching implications on the earth as we know it. This is because environmental pollution occasioned by heavy metals (HMs) which are non-biodegradable pose direct or indirect negative effects on environmental health, including that of plants, animals, and humans owing to their increased bioaccumulation in environmental matrices. Wastewater from industries producing chemicals is disposed of directly without proper treatment into the environment. However, HMs enter the food chains and food webs via the air, water, and soil, thereby inducing several diseases and disorders in both humans and animals. The features of rice husk (RH) as novel adsorbent are because it is chemically stable as well as being insoluble in water in addition to its large surface area relative to other agricultural waste products. There is an increasingly high awareness of the roles played by RH in environmental uses or applications for the sequestration of environmentally harmful chemical substances This review summarizes some recent developments in the use of RH and its derivatives as an environmentally friendly adsorbent that is highly suitable for the removal of heavy metal.