**7. Role of agro/food waste as biosorbents for the eradication of toxic metal ions**

Utilization of agro and food waste as biosorbents for the eradication of toxic metal ions from the wastewater and aqueous streams is a promising and innovative technology [35]. In the past several years, this promising technology has gained more attention because these waste materials have shown a higher efficacy towards the removal of heavy metals and the other reasons include low cost, and easy availability. The efficacy of agro/food waste depends upon its phsico-chemical nature, capacity of adsorption and affinity. A lot of research has already been carried out for the removal of heavy metals such as arsenic, lead, mercury, cadmium, chromium, nickel, cobalt, etc. by using various types of biosorbents namely rice husk, wheat bran, peels of apple and banana, etc. [14, 46–48]. They have used biosorbents either in the natural form or in modified form by thermal and chemical treatment to increase their sorption capacities.
