矿物-腐殖酸复合体对菲的吸附研究

摘要:选用高岭土、蒙脱土、针铁矿为代表性矿物，腐殖酸（HA）为代表性有机质，制备了矿物-HA复合体，通过FTIR、XRD、DSC等表征手段分析HA与矿物复合前后的形态结构的变化，并研究不同溶液化学条件下HA与矿物复合前后对菲吸附规律. 结果表明:与矿物复合后HA的玻璃态转变温度Tg由64.6℃变为32.6（高岭土-HA）、51.5（针铁矿-HA）、16.5、77.7℃（蒙脱土-HA），体现了HA的结构及致密程度发生了改变. 矿物-HA复合体对菲吸附的Koc值比未复合的HA减小50%左右，线性程度有所增强. 相对于Ca2+而言，Na+的存更有利于HA及其复合体对菲的吸附. 离子强度对菲在不同矿物-HA复合体上吸附的影响并不完全一致；较低的pH 4有利于菲在各种矿物-有机质复合体上的吸附，此时，蒙脱土-HA复合体对菲的吸附亲和力最大. 研究为阐明HOCs在土壤/沉积物中的迁移转化规律具有重要的意义.

Phenanthrene Sorption on Kaolin-HA,Montmorillonite-HA and Goethite-HA

Abstract: In order to study the interactions between humic acid and soil minerals on the sorption of hydrophobic organic pollutants (HOCs), kaolin, montmorillonite and goethite were selected to be synthesized with HA and the resulted complexes were characterized by FTIR, XRD and DSC for their morphological and structure. The effect of different solution chemistry on phenanthrene sorption on HA and mineral-HA complexes were studied. The results show that the glass transition temperature changed from 64.6℃(HA) to 32.6℃(kaolin-HA), 51.5℃(goethite-HA), 16.5℃ and 77.7℃(montmorillonite-HA), suggesting the change of HA structure. The Koc value of phenanthrene adsorption by mineral-HA complexes were about 50% less than that of HA and the sorption linearity increased. HA and three mineral-HA complexes in Na+ solution showed higher Koc value than that in Ca2+ solution. While, the ionic strength showed different influences in phenanthrene sorption on HA and 3 mineral-HA complexes. Lower pH favored the sorption of phenanthrene on the 3 mineral-HA complexes, and montmorillonite-HA exhibited the greatest sorption affinity for phenanthrene at pH 4. The results of this research could help to elucidate the transport and transformation of HOCs in soils and sediments.