李燕捷,马天行,郭学涛,杨琛,党志.纳米二氧化钛负载腐植酸对菲的吸附行为[J].农业环境科学学报,2014,33(11):2247-2253. |
纳米二氧化钛负载腐植酸对菲的吸附行为 |
Sorption of Phenanthrene on Nano-TiO2 Coated with Humic Acid |
投稿时间:2014-03-18 |
DOI:10.11654/jaes.2014.11.025 |
中文关键词: 纳米二氧化钛 腐植酸 菲 吸附 |
英文关键词: humic acid titanium dioxide sorption phenanthrene |
基金项目:国家自然科学基金资助项目(41072268);广州市珠江科技新星项目(2011J2200060) |
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中文摘要: |
为了研究腐植酸存在条件下纳米二氧化钛对水体污染物迁移的影响,提取两种代表性腐植酸(泥炭腐植酸和底泥腐植酸),研究了腐植酸存在条件下菲在纳米二氧化钛上的吸附行为。吸附实验采用批量平衡振荡法,考察吸附动力学、菲初始浓度以及环境因素(pH值和离子强度)对吸附的影响。结果表明:腐植酸负载到纳米二氧化钛的表面后,使纳米二氧化钛对菲的吸附能力显著提高,纳米二氧化钛对菲的吸附系数为6.71 L·kg-1,负载这两种腐植酸后吸附系数分别为715、348 L·kg-1,并且芳香碳含量高的腐植酸对吸附容量的增量效果明显高于脂肪碳含量高的腐植酸;负载腐植酸后对菲的吸附速率明显加快,吸附平衡时间由168 h减为48 h,并且吸附动力学符合二级动力学模型。体系的pH值和离子强度变化均能影响菲的吸附,可能与不同pH值和离子强度下附着在纳米二氧化钛表面的腐植酸结构不同有关;芳香碳含量高的腐植酸对吸附的影响作用更容易随pH值和离子强度的变化而改变,可能与其在不同条件下的结构变化有关。因此,在评价纳米二氧化钛的环境效应时,腐植酸以及环境因素的影响不容忽视。 |
英文摘要: |
Nano-TiO2 has strong adsorption of pollutants. Humic acid(HA) is a natural organic substance and also influences the environmental fates of pollutants. A bath adsorption experiment was conducted to study the sorption of phenanthrene on nano-TiO2 as influenced by initial concentrations of phenanthrene, pH values and ionic strength under the presence of peat HA and sediment HA. The sorption kinetics of phenanthrene was also investigated. The Kd value of nano-TiO2 was 6.71 L·kg-1, while that of nano-TiO2 coated with peat and sediment HA was 715 L·kg-1 and 348 L·kg-1, respectively, indicating that HA coating enhanced the sorption of phenanthrene on nano-TiO2. The increment of sorption by aromatic-rich HA was significantly greater than that by aliphatic-rich HA. The equilibrium time decreased to 48 h from 168 h under the presence of HA, implying a quicker equilibrium of phenanthrene sorption on nano-TiO2 coated with HA.The kinetics of phenanthrene sorption followed the pseudo second-order rate equation. Both pH and ionic strength had greater influence on phenanthrene sorption by nano-TiO2 coated with aromatic-rich HA than with aliphatic-rich HA. Therefore, the influence of humic acid and environmental factors should not be ignored when evaluating the environmental impacts of nano-TiO2. |
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