花生壳活性炭的表征,表面改性及吸附脱除水中Pb2+离子（英文）

Metal ion contamination of drinking water and waste water, especially with heavy metal ion such as lead, is a serious and ongoing problem. In this work, activated carbon prepared from peanut shell (PAC) was used for the removal of Pb2+ from aqueous solution. The impacts of the Pb2+ adsorption capacities of the acid-modified carbons oxidized with HNO3 were also investigated. The surface functional groups of PAC were confirmed by Fou-rier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), Boehm titration. The textural properties (surface area, total pore volume) were evaluated from the nitrogen adsorption isotherm at 77 K. The ex-perimental results presented indicated that the adsorption data fitted better with the Langmuir adsorption model. A comparative study with a commercial granular activated carbon (GAC) showed that PAC was 10.3 times more effi-cient compared to GAC based on Langmuir maximum adsorption capacity. Further analysis results by the Langmuir equation showed that HNO3 [20% (by mass)] modified PAC has larger adsorption capacity of Pb2+ from aqueous solution (as much as 35.5 mg·g-1). The adsorption capacity enhancement ascribed to pore widening, increasedcation-exchange capacity by oxygen groups, and the promoted hydrophilicity of the carbon surface.