Adsorption capacity and removal efficiency of heavy metal
ions by Moso and Ma bamboo activated carbons
a b s t r a c t
In order to understand the adsorption capacity and removal efficiency of heavy metal ions by Moso and Ma bambooactivated carbons, the carbon yield, specific surface area, micropore area, zeta potential, and the effects of pH value,soaking time and dosage of bamboo activated carbon were investigated in this study. In comparison with onceactivatedbamboo carbons, lower carbon yields, larger specific surface area and micropore volume were found for thetwice-activated bamboo carbons. The optimum pH values for adsorption capacity and removal efficiency of heavy
metal ions were 5.81–7.86 and 7.10–9.82 by Moso and Ma bamboo activated carbons, respectively. The optimumsoaking time was 2–4 h for Pb2+, 4–8 h for Cu2+ and Cd2+, and 4 h for Cr3+ by Moso bamboo activated carbons, and 1 hfor the tested heavy metal ions by Ma bamboo activated carbons. The adsorption capacity and removal efficiency of heavy metal ions of the various bamboo activated carbons decreased in the order: twice-activated Ma bamboocarbons > once-activated Ma bamboo carbons > twice-activated Moso bamboo carbons > once-activated Moso bamboo
carbons. The Ma bamboo activated carbons had a lower zeta potential and effectively attracted positively chargedmetal ions. The removal efficiency of heavy metal ions by the various bamboo activated carbons decreased in theorder: Pb2+ > Cu2+ > Cr3+ > Cd2+.