【摘要】 以膨润土和凹凸棒石为原料,用阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)对膨润土和凹凸棒石进行改性,分别制备矿物阳离子交换量/十六烷基三甲基溴化铵(n/n)=1∶1和1∶0.5的有机改性矿物。采用室内批量法研究矿物及其改性产物对氯磺隆的吸附效果,探讨pH值和温度对供试矿物吸附氯磺隆的影响,并采用FTIR对矿物结构进行表征。结果表明:矿物改性后,有机改性矿物对氯磺隆的吸附能力较原矿物明显增强;1∶1型改性矿物的吸附能力大于1∶0.5型改性矿物;膨润土及其改性矿物对氯磺隆的吸附能力大于相应的凹凸棒石。供试样品吸附氯磺隆的量均随溶液的pH值升高而逐渐减小,随温度升高而增加。更多还原

【Abstract】 In order to understand the adsorption of mineral and its modified products to herbicides,bentonite and appapulgite were used as the raw materials,and cationic surfactant hexadecyl trimethyl ammonium bromide(CTAB)was used to modify the bentonite and appapulgite.The organically modified minerals were prepared with the ratios of ECE/n(CTAB)=1∶1 and 1∶0.5,respectively.The equilibrium batch of chlorsulfuron adsorption on mineral and its modified products was investigated.The effects of pH and temperature on the adsorption of chlorsulfuron in the tested minerals samples were studied.The FTIR spectra of minerals modified with or without CTAB were characterized.The results showed that when the minerals were modified with CTAB,their adsorption capacities of chlorsulfuron were more than those of the original minerals significantly.The ability to adsorb chlorsulfuron of the 6 minerals samples was in the order of 1∶1 modified bentonite>1∶1 modified appapulgite>1∶0.5 modified bentonite>1∶0.5 modified appapulgite>unmodified bentonite>unmodified appapulgite.For example,at pH=7 and t=30℃,the maximum adsorption amount of 1∶1 modified bentonite,1∶1 modified appapulgite,1∶0.5 modified bentonite,1∶0.5 modified appapulgite,unmodified bentonite,and unmodified appapulgite was 3 930,2 667,979.0,3 991,3 029 and 1 505 mg/kg,respectively.It is concluded that the adsorption capacity of 1∶1 modified minerals was greater than that of 1∶0.5 type modified minerals.The adsorption capacity of bentonite and its modified minerals to chlorsulfuron was greater than that of the appapulgite.It also showed that the adsorption ability of organic modified minerals to the chloride was much better than that of the original minerals.The amount of adsorbed chlorsulfuron in the tested sample was gradually decreased with the increase of the solution pH.The amount of adsorbed chlorsulfuron in the tested samples increased with the increase of temperature as well.Adsorption thermodynamic was conformed to Freundlich isothermal adsorption model.It is indicated that the adsorption was spontaneous and exothermic process.It will provide scientific reference for the application of modified minerals in the field experiment on slow-release pesticides and the organic pollutants removal in environment.更多还原