XING Ying1, 2, LEE Xin-qing1, ZHOU Zhi-hong1,2, CHENG Hong-guang1, FANG Bin1,2, ZHANG Like1,2
(1. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China;
2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China)
Abstract: The experiment was conducted on the adsorption characteristics of biochar for removing ammonium in aqueous medium. The adsorption equilibrium and kinetic behavior of ammonium onto biochar was investigated by a series of batch adsorption experiments, and adsorption mechanism was discussed from the kinetic point of view. Results indicated that ammonium adsorption equilibrium was reached in about 60 minutes, and the capacity of biochar adsorbing ammonium tended to increase with increasing concentrations of ammonium in water . The Langmuir isotherm equation could well describe the isothermal adsorption behavior of ammonium on biochar, and the Langmuir maximum adsorption capacity was 1.24 mg/g. The pseudo-second-order model was found to explain the adsorption kinetics most effectively, and pore diffusion, surface adsorption and intra-particle diffusion would affect the adsorption.
Key words: biochar; ammonium nitrogen; adsorption mechanism
EARTH AND ENVIRONMENT Vol. 39, No.4, Tot No.286, 2011, Page 511-516
