| dc.description.abstract | The natural soil possesses negatively charged and has high affinity for metal cations. But for the nonionic organic contaminats, due to lack of organic matters content, the capacity of partitioning is not effectively. Thus, the natural soil is not effective for the simultaneous removal of both organic and inorganic contaminats. In recent years, the researches of block copolymer are developed and have been widely applied on nanomaterial. Therefore, in this study, we use kaolinite, illite and Ca-montmorillonite which are intercalated diblock copolymer and tribiock copolymer separately to prepare clay-composite materials. Exploring the adsortion capacity of these clay-composite materials for noionic, cation and anion contaminats.
From the characterization analysis of the clay-composite materials, we found that the organic carbon content of these three soils was higher than that before been modified. The FTIR analysis, the spectrum showed that the modified clay suface contained the specific functional group of the block copolymer. As for the X-ray diffraction (XRD) technique was applied to reveal intercalated materials in the layer, which provides informations on layered structure and the basal spacing. The results showed that the basal spacing of the modified clays all increased and the increased degree was mainly dependent on the molecular weight and intercalated amount of the block copolymer. Finally, the ASAP analysis showed that the specific surface area decreased and the pore size increased after soil modification. These analytical data comfirmed that the block copolymer has been intercalated into the inter-layer of soil successfully.
The BTEX experimental results showed that although the modified clay organic matter content is increased, due to the structural properties of the modifier, the partitioning effect was defferent. Simultaneously, it can been observed that the partition coefficient (Kd) was indeed related to the organic matter content. Comparing to the literatures, the modified clay of this study possesses better distribution ability and higher log Kom values. The adsorption experiment of inorganic contaminats (Cu2+, Pb2+, Cr2O72-) showed that the modified clay with carboxyl group has the highest adsorption capacity for Cu2+ and Pb2+ under alkaline conditions. The modified clay with amine group has the highest adsorption capacity for Cr2O72- under acidic conditions. The modified clay with both carboxyl and amine group have the middle adsorption capacity for cation and anion contaminats. The adsorption capacity of inorganic contaminats adsorbed by each modified soil is higher than natural soil of the literature. Eventually, the results of comprehensive organic partitioning and inorganic adsorption experiments confirmed that the modified clay with block copolymer of this study provide the affinity of nonionic (BTEX), cation (Cu2+, Pb2+), anion (Cr2O72-) contaminats.
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