Adsorption of heavy metal ions and synthetic dyes from aqueous solution onto adsorbents is one of the dominant treatment techniques. Activated carbon, carbon nanotubes and nanosorbents are found to be the most efficient adsorbent for the removal of heavy metal ions and dyes. In spite of the superiority exhibited, the cost of activation, synthesis and regeneration limits the application of above materials at commercial stage. Agricultural wastes and by products were found to be low cost and investigated as alternate adsorbents for the removal of heavy metal ions and dyes. Agro wastes are rich in organic contents with variety of functional groups which can cooperate binding of cations and anions. The other advantages of agricultural wastes are easily available, non-hazardous and no disposal problems. Chemical activation or modification of adsorbents exhibited increased removal efficiency and loading capacities. In view of the above reports, the present book deals with use of a low cost adsorbent such as watermelon rind in its native and pretreated form for the removal of heavy metal ions and synthetic dyes from aqueous solution.