Chemical behavior of organic compounds in the interface of water/dual-cation organobentonite

The sorption behavior of polar or ionizable organic compounds, such as p nitrophenol, phenol and aniline, in the water/organobentonite systems is investigated. Both adsorption and partition occur to the sorption of organic compounds to dual cation organobentonites. The separate contributions of adsorption and partition to the total sorption of organic compounds to dual cation organobentonites are analyzed mathematically in the first time. The factors to the contributions are also discussed. The results indicated that the contribution of adsorption and partition is related to the composition and ratio of dual cation surfactants exchanging onto the bentonite. The sorption of organic compounds to dual cation organobentonite is dominated by adsorption at low concentrations and by partition at high concentrations, making the organobentonites powerful sorbents for organic contaminants over wide range of concentrations.