title: Adsorption-desorption behavior of acetochlor to soils in the presence of some environmental substances.
abstract: The behavior of herbicide acetochlor adsorption-desorption to soil in the presence of humic acid (HA), anionic surfactant sodium dodecylbenzene sulfonate (SDBS), cationic surfactant hexadecyltrimethyl-ammonium bromide (HDAB) and NH4NO3 as a chemical fertilizer was studied. Observed acetochlor adsorption isotherm were well described using Freundlich isotherm equation, from which the desorption isotherm equation has been deduced. The deduced equation can more directly describe acetochlor desorption process. The results showed that the enhance of acetochlor adsorption capacity by solid HA was greater than by soluble HA. The presence of NH4 NO3 can slightly enhance acetochlor adsorption to soil by comparison with that measured in NH4 NO3-free solution. In soil-water system, surfactant-acetochlor interaction is very complex, and the surfactant adsorptions as well as acetochlor adsorption need to be considered. When acetochlor-soil suspensions contained lower concentration SDBS or HDAB (40 mg/L), Kf for acetochlor adsorption was decreased in comparison to that measured in SDBS- or HDAB-free solution. When acetochlor-soil suspensions contained higher concentration SDBS or HDAB (corresponding 1400 mg/L or 200 mg/L), Kf for acetochlor adsorption was increased in comparison to that measured in SDBS- or HDAB-free solution.
authors.affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. yechm@mail.rcees.ac.cn
authors.forename: Chang-ming
authors.initials: CM
authors.lastname: Ye
authors.forename: Zhi-fang
authors.initials: ZF
authors.lastname: Lei
mesh_terms: D000327:Adsorption; D000838:Anions; D001557:Benzenesulfonates / Q000737:chemistry*; D006540:Herbicides / Q000737:chemistry*; D006812:Humic Substances / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry*; D014052:Toluidines / Q000737:chemistry*; D014867:Water
chemical_list: D000838:Anions; D001557:Benzenesulfonates; D006540:Herbicides; D006812:Humic Substances; D012989:Soil Pollutants; D013501:Surface-Active Agents; D014052:Toluidines; D014867:Water; C001114:dodecylbenzenesulfonic acid; C043377:acetochlor