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主要研究了以不同比例十六烷基三甲基溴化铵(CTMAB)单一修饰和十六烷基三甲基溴化铵+十二烷基磺酸钠(CTMAB +SDS)混合修饰的土耕层、黏化层土样对重金属镉离子的吸附。结果表明:吸附量顺序分别为耕层原土(GCK) >CTMAB5 0 %修饰改性土(5 0GCB) >CTMAB10 0 % +SDS2 0 %修饰改性土(12 0GCS) >CTMAB10 0 %修饰改性土(10 0GCB)和粘化层原土(NCK) >CTMAB5 0 %修饰改性土(5 0NCB) >CTMAB10 0 %修饰改性土(10 0NCB) >CTMAB10 0 % +SDS2 0 %修饰改性土(12 0NCS)的顺序,表明以表面修饰剂修饰土表面,确实存在着使得镉离子吸附能力减弱的趋势,但并未使修饰改性土完全丧失对于镉离子的吸附能力;吸附等温线可以用Langmuir方程描述;热力学参数的研究表明Cd2 + 吸附反应是熵增控制的自发性过程,但在探讨吸附自发性和最大吸附量关系时应考虑土壤本身的容量性质。机理研究认为,表面修饰剂对土壤表面的修饰改性是不均匀的,阳离子交换吸附和疏水键键合两种机制的竞争性吸附是修饰改性土壤依然具有对镉离子吸附作用的原因。土耕层各改性土样对Cd2 + 吸附的温度效应明显高于粘化层土样,证实了耕层对镉离子的化学吸附作用强于粘化层的结果
Mainly studied with different proportions of cetyltrimethylammonium bromide (CTMAB) single modification and cetyl trimethyl ammonium bromide + sodium dodecyl sulfate (CTMAB + SDS) mixed modified soil Tillage, clay soil samples of heavy metal cadmium ions adsorption. The results showed that the order of adsorption amount was as follows: GCK> CTMAB5 0% modified soil (5 0GCB)> CTMAB10 0% + SDS2 0% modified soil (12 0GCS)> CTMAB10 0% modified modified (10 0GCB) and clay soil (NCK)> CTMAB5 0% modified soil (5 0NCB)> CTMAB10 0% modified soil (10 0NCB)> CTMAB10 0% + SDS2 0% Modified soil (12 0NCS), indicating that the surface modification agent modified soil surface, there is indeed a tendency to weaken the adsorption capacity of cadmium ions, but did not make the modified soil completely lost to the adsorption capacity of cadmium ions; adsorption isotherm can The Langmuir equation was used to describe the adsorption capacity of Cd2 +. The study of thermodynamic parameters showed that the Cd2 + adsorption reaction is a spontaneous process of entropy increase control. However, the capacity of soil itself should be considered when discussing the relationship between adsorption spontaneity and maximum adsorption capacity. Mechanism studies suggest that the modification of the soil surface with surface modifiers is not uniform, and the competitive adsorption of cation exchange and hydrophobic bonding is the reason that the modified soil still has the effect of cadmium ion adsorption.温 soil temperature of the modified soil samples for Cd2 + adsorption temperature was significantly higher than the clay soil samples, confirmed that the chemical adsorption of plow layer of cadmium ions stronger than the results of the sticky layer