التفاصيل البيبلوغرافية
| العنوان: |
Mechanisms and Factors Influencing Adsorption of Nitroaromatic Compounds by Smectite Clays. |
| المؤلفون: |
Li, Liang, Ding, Jing |
| المصدر: |
Water, Air & Soil Pollution; Oct2024, Vol. 235 Issue 10, p1-15, 15p |
| مصطلحات موضوعية: |
NITROAROMATIC compounds, SMECTITE, IONIC solutions, SURFACE charges, ELECTRIC potential |
| مستخلص: |
To better understand the transport behavior of nitroaromatic compounds (NACs) in soils, it is significant to systematically evaluate the factors influencing NACs adsorption to smectite clays and thoroughly elucidate major interactive mechanisms. The binding affinity of smectite clays for NACs was clearly influenced by both interlayer cations and surface charge density of smectite. When saturated with K+, Cs+ or NH4+, smectite clays exhibited higher binding abilities for 2,4-dinitrobenzene (2,4-DNT), as compared to those saturated with Na+, Ca2+ or Al3+. A negative correlation existed between the charge density of K+-smectite and its binding ability for 2,4-DNT (not including the smectite with the lowest charge density). As pH decreased, the main interaction between dissociable NACs and smectite clays shifted from the electrostatic repulsion to the specific adsorption, resulting in higher adsorption at lower pH. With higher solution ionic strength, the quasi-crystal structure of smectite formed mainly due to the better-ordered lamellae, which led to the stronger sorption potential of the smectites for NACs. The adsorption of dimethylnitrobenzenes differed to some extent among the isomers, attributed to the steric hindrance related to the position of nitro and methyl groups. The adsorption of NACs was promoted slightly due to substitution of -CH3 for -H and considerably substitution of -NO2 for -CH3. The presence of cation binders (crown ether 18c6e and 15c5e) evidently weakened the adsorption of 2,4-DNT by K+- and NH4+-smectite. Macroscopic adsorption results, along with electronic property of NAC molecules (atomic charge and electrostatic potential), demonstrated that the electrostatic interaction between smectite cations and nitro of NACs was the predominant force in mediating their adsorption. [ABSTRACT FROM AUTHOR] |
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| قاعدة البيانات: |
Complementary Index |