【摘要】 为了探索添加不同复配修饰两性黏土对紫色土吸附Cu²⁺的影响,分别采用50%和100%CEC的阴离子型聚丙烯酰胺（APAM,简写为PA）、柠檬酸（CA）、乙二胺四乙酸（EDTA,简写为ED）和十二烷基磺酸钠（SDS,简写为SD）对50%CEC十二烷基二甲基甜菜碱（BS-12或BS）修饰麦饭石进行复配修饰,并将复配修饰后的麦饭石以1%的质量比加入到紫色土（PS）中,形成PS50BS+PA（PS中添加1%的50%BS+PA修饰麦饭石,下同）、PS50BS+CA、PS50BS+ED、PS50BS+SD四类混合土样。批处理法研究各混合土样对Cu²⁺的等温吸附和热力学特征,并对比不同pH值、温度和离子强度对Cu²⁺吸附的影响。结果表明:不同混合土样对Cu²⁺吸附等温线均呈"L"型且符合Langmuir模型。各混合土样对Cu²⁺的最大吸附量qm在94.90～144.80 mmol·kg-1之间,表现为PS50BS+PA> PS50BS+CA>PS50BS+SD> PS50BS+ED> PSBS> PS的趋势,且相同复配修饰模式下Cu²⁺吸附量在100%复配修饰比例更佳。20～40℃范围内,除PS50BS+PA和PS50BS+SD以外,供试土样对Cu²⁺的吸附量均随温度的升高而升高,增加幅度为8.29%～15.99%。pH值3～5范围内,各混合土样对Cu²⁺的吸附量均随着pH值的升高而升高。各混合土样（除PS50BS）对Cu²⁺的吸附量均随着离子强度的增加而降低,以0.01 mol·L^-1最佳。混合土样对Cu²⁺的吸附为自发和熵增的过程,且除PSBS+PA和PS50BS+SD外的土样对Cu²⁺的吸附为吸热反应。更多还原

【Abstract】 To explore the effect of addition of different compositely modified amphipathic clays on Cu²⁺adsorption by purple soil, 50% and100% CEC of anionic polyacrylamide（APAM, abbreviated as PA）, citric acid（CA）, ethylenediamine tetraacetic acid（EDTA, abbreviated as ED）, and sodium dodecyl sulfate（SDS, abbreviated as SD）were used to compositely modify 50% CEC of lauryl dimethyl betaine（BS-12 or BS）-modified maifanite. Subsequently, the different compositely modified maifanites were added to purple soil（PS）with a mass ratio of 1% to form four types of mixed soil samples, such as PS50 BS+PA（addition of 1% 50 BS+PA-modified maifanite into PS, similarly hereinafter）, PS50 BS+CA, PS50 BS+ED, and PS50 BS+SD. The adsorption isotherms and thermodynamic characteristics of Cu²⁺on the various mixed samples were studied by batch treatment, and the adsorption effects of pH values, temperatures and ion strengths were evaluated. The results showed the following. The adsorption isotherms of Cu²⁺on the mixed samples were all "L" type and accorded with the Langmuir model. The maximum adsorption amount of Cu²⁺on the mixed samples changed between 94.90 mmol·kg-1 and 144.80 mmol·kg-1, and presented the trend of PS50 BS+PA > PS50 BS+CA > PS50 BS+SD > PS50 BS+ED > PS50 BS > PS. At the same composite modification mode, Cu²⁺adsorption showed a good adsorption amount at the composite modification ratio of 100%. In the range of 20～40 ℃, the adsorption amount of Cu²⁺on the tested soils increased with the increase in temperature, except that on PS50 BS+PA and PS50 BS+SD, and the increasing range was 8.29%～15.99%. Within the pH range of 3～5, Cu²⁺adsorbed by each mixed soil increased with the increase in pH. The adsorption amount of Cu²⁺on the mixed soils（except that on PS50 BS）decreased with the increase in ionic strength, which was the highest at 0.01 mol·L^-1. The adsorption of Cu²⁺on the mixed samples（except that on PS50 BS+PA and PS50 BS+SD）was a spontaneous and entropy increasing process, and the process showed an endothermic reaction.更多还原