title: Sorption kinetics of toluene in humic acid: a computational approach.
abstract: Molecular dynamics, a computational technique aiming to describe the time-dependent movement of molecules, has been applied to study the sorption kinetics of volatile organic contaminants in soil organic matter. The molecular dynamics simulation results obtain reasonably accurate estimates of diffusion rates and activation energy of the penetration of a volatile organic compound molecule into a model humic substance. The sorption rate of toluene to humic acid decreases with the density of the humic acid matrix and increases with temperature. All the present results indicate that the sorption of toluene into humic acid is mainly diffusion controlled. Finally, the present studies have shown that molecular dynamics of volatile organic compounds in humic substances yields meaningful results, which help in the understanding of diffusion at the molecular level and which facilitate the problem-solving capability for removing the contaminants from the soils.
authors.affiliation: Department of Soil and Environmental Sciences, Center of Nanoscience and Nanotechnology, National Chung Hsing University 250, Kuo-Kuang Road, Taichung 402, Taiwan, Republic of China. yhs@nchu.edu.tw
authors.forename: Yang-Hsin
authors.initials: YH
authors.lastname: Shih
authors.forename: Shian-Chee
authors.initials: SC
authors.lastname: Wu
authors.forename: Jyh-Shing
authors.initials: JS
authors.lastname: Lin
authors.forename: Lien-Feng
authors.initials: LF
authors.lastname: Lee
mesh_terms: D000327:Adsorption; D004058:Diffusion; D006812:Humic Substances; D007700:Kinetics; D008956:Models, Chemical; D015394:Molecular Structure; D012989:Soil Pollutants; D013816:Thermodynamics; D014050:Toluene / Q000737:chemistry*; D014835:Volatilization
chemical_list: D006812:Humic Substances; D012989:Soil Pollutants; D014050:Toluene