Clean water and its requirement are one of the emerging needs in recent days. Water pollution creates more amount of toxic nature to the clean water and it increases the accumulation of poisonous contaminants in the water sources. Heavy metal ions are the type of toxic pollutant released from textile industrial effluent, changes the natural color of clean water. In this study, Adsorption behavior with activated biochar Gracilaria Edulis as adsorbent was investigated under batch mode for removing detecting elevated levels of metallic cations in aqueous solutions. The biochar adsorbent was prepared with chemical synthesis process and their surface area analyzed using N2 adsorption process. The presence of targeted heavy metal ions was confirmed using SEM and EDX analysis. The maximum adsorption efficiency of 99.9% of Cr, 97.37% of Ni and 92.73% of Zn heavy metal ions was achieved using the biochar adsorbent. The endothermic reaction in between adsorbent and adsorbent was confirmed using the thermodynamic studies and maximum amount of spent adsorbent was recovered by using desorption process by adding strong hydrochloric acid with 0.3 N.