表面活性剂对链霉素在内蒙古牧区土壤中吸附解吸的影响

Effect of surfactants on sorption and desorption of streptomycin on soil of Inner Mongolian pastoral area

通过静态吸附实验,研究了3种不同类型的表面活性剂(阳离子:十六烷基三甲基溴化铵,CTAB;阴离子:十二烷基苯磺酸钠,SDBS;非离子,曲拉通100,TX-100)对链霉素(Streptomycin,STR)在内蒙古牧区土壤中吸附解吸的影响。结果表明,3种表面活性剂的存在均会增加STR在土壤中吸附的线性程度。CTAB的存在抑制了STR在土壤表面的吸附同时抑制了STR的解吸,然而SDBS的存在降低了STR在土壤中的吸附量并增加了吸附过程的可逆性。与CTAB和SDBS不同,TX-100对STR在土壤中的吸附的影响取决于其添加浓度。低浓度的TX-100对STR的吸附促进作用大于高浓度。随着TX-100浓度的增加,TX-100对STR的增溶作用加剧。促使吸附在土壤表面的STR迁移到水相中,从而抑制了STR的吸附,进而促进了STR的解吸。

Sorption and desorption of Streptomycin （STR） onto soil of Inner Mongolian pastoral area extracted from sediment were studied in the presence of three types of surfactants （cetyltrimethylammonium bromide, CTAB; sodium dodecylbenzene sulfonate, SDBS; Triton X- 100, TX- 100） to examine the role of surfactants in sorption and desorption. Linearity of the sorption isotherms of STR increased in the presence of surfactants. CTAB inhibit the sorption capacity and irreversibility of STR on soil.However, the presence of SDBS reduced the sorption capacity and desorption hysteresis. Unlike CTAB and SDBS,the influence of TX- 100 on sorption and desorption was concentration dependent. Low levels of TX- 100 enhanced STR sorption than high levels.With increasing concentration of TX-100, TX-100 solubilization effect of the STR is intensified. Adsorption migrate to the water phase at the surface of the soil, thus inhibiting the adsorption of the STR and promoting desorption of the STR