Novel adsorbent was produced from rice husks and rice straw derived biochar. The adsorbent was synthesized by subjecting to pyrolysis agricultural waste and activated the product with thermochemical treatments to enhance its properties. The effects of alkali concentration, process temperature and reaction time on the agricultural waste derived biochar were assessed and results showed that the activation of biochar enhanced its specific surface area by 58.5 to 220.8 square meter per gram. The total pore volume of the biochar also increased from 0.33 cm3 per gram to a maximum of 0.45 cm3 per gram upon activation. The Langmuir equation was used to predict sorption capacity of Lead (Pb2+) by the pristine and thermochemically treated biochar, with maximum sorption 0.25 mol/kg and 1.44 mol/kg, respectively.
