• 关键词：复配修饰  膨润土  苯酚  菲  吸附

• 基金项目：国家自然科学基金（No.41271244）；陕西省重点研发计划（No.2017SF-385）

• 王腾
• 西北农林科技大学资源环境学院, 杨陵 712100

• 孟昭福
• 1. 西北农林科技大学资源环境学院, 杨陵 712100;2. 农业部西北植物营养与农业环境重点实验室, 杨陵 712100

• 任爽
• 西北农林科技大学资源环境学院, 杨陵 712100

• 张洋
• 西北农林科技大学资源环境学院, 杨陵 712100

• 刘伟
• 1. 西北农林科技大学资源环境学院, 杨陵 712100;3. 新疆工程学院化学与环境科学工程系, 乌鲁木齐 830091

• 李文斌
• 西华师范大学环境科学与工程学院, 南充 637009

• 田凯
• 西北农林科技大学资源环境学院, 杨陵 712100

• 摘要：为了探究复配修饰膨润土吸附疏水性不同的污染物的差异，采用阳离子型表面修饰剂十二烷基三甲基溴化铵（DTAB）对两性表面修饰剂十二烷基二甲基甜菜碱（BS-12）修饰膨润土进行复配修饰，采用批处理法研究复配修饰膨润土总修饰比例对苯酚和菲的等温吸附影响，并对比不同温度、pH值和离子强度条件下供试土样对苯酚和菲吸附量、热力学参数的差异.结果表明：随着总修饰比例的增大，复配修饰膨润土对苯酚及菲的吸附能力逐渐增强，0~50%CEC修饰比例下，菲的吸附率大于苯酚的吸附率，当修饰比例超出50%CEC后，苯酚的吸附率大于菲的吸附率，总修饰比例超出150%CEC后，膨润土对苯酚的吸附率变化趋于平缓，而对菲的吸附率开始呈下降趋势；随着土样总修饰比例的增大，温度对苯酚及菲吸附量的抑制效果降低；在KNO₃浓度为0.001~0.1 mol·L^-1时，苯酚及菲的吸附量均随着KNO₃浓度的增大而增大；随着pH值的升高，苯酚的吸附量逐渐增大，在pH=7处达到最大，而菲的吸附量则始终呈降低趋势.热力学参数显示，随着总修饰比例的增大，复配修饰土样对苯酚和菲的吸附自发性增强，混乱度增大，当总修饰比例超出150%CEC后，自发性减弱，混乱度下降.

• Abstract：To investigate the differences between phenol and phenanthrene adsorption on bentonite modified by a mixture of amphoteric modifier, dodecyl dimethyl betaine (BS-12), and cationic modifier, dodecyltrimethylammonium bromide (DTAB). Batch experiment was conducted to study influence of total modifier ratios (TMR), ionic strength, temperature, and pH on the differences in adsorption, and the thermodynamic properties were investigated as well. The results showed that the adsorption of phenol and phenanthrene on modified bentonite increased with an increase of TMR. The adsorption rate of phenanthrene was higher than phenol in region of 0~50% of CEC TMR, but was lower than phenol when TMR was greater than 50% CEC. When TMR was beyond 150% CEC, the adsorption rate of phenanthrene decreased while the adsorption rate of phenol tended to be gentle. The inhibition effect of temperature on phenol and phenanthrene adsorption decreased with TMR. Ionic strength enhanced phenanthrene adsorption in the range of 0.001~0.1 mol·L^-1 KNO₃ concentration. With the increase of pH, phenol adsorption increased gradually and reached the maximum adsorption at pH=7, while phenanthrene adsorption decreased. The thermodynamic parameter results indicated that the adsorption of phenol and phenanthrene is a spontaneous process with both enthalpy and entropy increase in the region of 0~150% CEC ratio, while an opposite change, i.e. enthalpy and entropy decrease, appears when TMR is higher than 150% CEC.

• Key words：combined modification  bentonite  phenol  phenanthrene  adsorption

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