Performance and mechanism for cadmium and lead adsorption from water and soil by corn straw biochar

作     者：Tong Chi Jiane Zuo Fenglin Liu 

作者机构：State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing 100084 China 

出 版 物：《Frontiers of Environmental Science & Engineering》 (环境科学与工程前沿（英文）)

年 卷 期：2017年第11卷第2期

页      面：157-164页

核心收录：

学科分类：12[管理学] 1201[管理学-管理科学与工程(可授管理学、工学学位)] 08[工学] 

基　　金：supported by the Major Science and Technology Programs for Water Pollution Control and Management of China 

主　　题：Corn strawBiocharHeavy metalsSorption isothermBioavailability 

摘      要：Cadmium （Cd） and lead （Pb） in water and soil could be adsorbed by biochar produced from corn straw. Biochar pyrolyzed under 400℃ for 2 h could reach the ideal removal efficiencies （99.24% and 98.62% for Cd and Pb, respectively） from water with the blochar dosage of 20 g. L^-1 and initial concentration of 20 mg.L^-1 . The pH value of 4-7 was the optimal range for adsorption reaction. The adsorption mechanism was discussed on the basis of a range of characterizations, including X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, Fourier transform infrared spectroscopy （FTIR） and Raman analysis; it was concluded as surface complexation with active sorption sites （-OH, -COO-）, coordination with 7c electrons （C = C, C = O） and precipitation with inorganic anions （OH-, CO3^2- , SO4^2- ） for both Cd and Pb. The sorption isotherms fit Langmuir model better than Freundlich model and the saturated sorptlon capacities for Cd and Pb were 38.91 mg·g^-1 and 28.99 mg.g^-1 , espectwely. When mixed with soil, biochar could effectively increase alkalinity and reduce bioavailability of heavy metals. Thus, biochar derived from corn straw would be a green material for both removal of heavy metals and amelioration of soil.