Biochar addition to soil and water environments has been shown to be effective in sequestering contaminants. This study evaluated the effects of biomass type and the preparation temperatures of biochars on their properties as a sorbent. Rice husk and empty fruit bunches of oil palm were used as the source of biomass for the production of biochars by heating at 300, 500 and 700°C. The biochars properties including functional sites, elemental components and BET surface area were determined to assess the biochars sorption mechanisms. The biochars produced in low temperature were found to have more polar functional groups effective in sorption of polar molecules while the highest temperature increased biochars surface area which is effective in nonselective sorption of contaminations. © (2014) Trans Tech Publications, Switzerland.