dc.description.abstract | Due to the composition and the sorption mechanism, natural soil dossesses low-affinity for both organic and inorganic pollutants. Many researchers have tried to modify the soil with organic contents in order to increase the holding capacity of organic pollutants in the modified soil. But due to the limits to the soil surface hydrophilic properties and narrow interlayer spaces, the macromolecular organic polymer is difficult to intercalate in the soil. As a result, the main purpose of this study is threefold: first, to modify the surface characteristics of the soil so as to make the soil suitable for performing subsequent modification; second, to investigate the factors behind the augmentation of organic matter into layer of the soil; and third, to discuss the sorption effect of the modified soil.
In this study,we use organic amine with different functional modified groups and sodium montmorillonite(Na-MMT) in order to increase the soil organic matter content the basal spacing, and furthermore, to increase the sorption of organic and inorganic pollutants.
The experimental results show that the specific surface area of the modified soil can ranked in the order as follows: 1,12-Diaminododecane(DDC)> 12-Aminododecanoic acid(ADA)> Octadecylamine(ODC). The modifiers successfully intercalate in the soil and increase the basal spacing. Modifiers with longer carbon chain can obviously increase more basal spacing. Compared to the other modified soils, ODC has the maximum basal spacing. Time and temperature almost did not affect the ODC basal spacing. With the addition of HCl, ODC basal spacing decreases after an initial increase, but DDC did not affect the basal spacing. Due to the characteristics of the functional groups and their way to bond with soil, the maximum amount of metal absorption (mg/g) was ranked as follows: DDC>ODC>ADA. If the organic content in the modified soil is higher.The larger distribution constant (Kd) was found. Also, there is an inverse correlation between Kom and the water solubility (Sw). The results of log Koc and log Kom are higher than the literature values, which show that the modified soil in this study is a well-distributed media.
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