The BET surface of biochar was determined after pyrolysis at different temperatures. The biochar of BC700 showed maximum BET surface area of 380.20 m2/g, followed by BC400 (0.84 m2/g) and BC250 (0.67 m2/g). The wood chips (WC) without heat treatment showed BET 0.30 m2/g. The increase of the pyrolysis temperature led to the elevated surface area of biochar, which facilitated higher sorption and correlated with the previous report