Centro de Investigación y Estudios de Posgrado, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Dr. M. Nava No.6, San Luis Potosí, SLP 78210, Mexico.
Centro de Investigación y Estudios de Posgrado, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Dr. M. Nava No.6, San Luis Potosí, SLP 78210, Mexico.
J Colloid Interface Sci. 2014 Dec 15;436:276-85. doi: 10.1016/j.jcis.2014.08.023. Epub 2014 Aug 19.
The adsorption of the antibiotic metronidazole (MNZ) on activated carbon (F400), activated carbon cloth (ACF), mesoporous activated carbon (CMK-3), and carbon nanotubes (MWCNT) was investigated in this work. The effect of the adsorbent-adsorbate interactions as well as the operating conditions (ionic strength, solution pH, temperature, chemical modification of the adsorbents by HNO3 treatment, and water matrix) on the adsorption capacity were analyzed to substantiate the adsorption mechanism. The adsorption capacity markedly varied as function of the carbon material, decreasing in the following order: F400>ACF>F400-HNO3>CMK-3>MWCNT>MWCNT-HNO3, and depended not only on their surface area and pore size distribution, but also on their chemical nature. The adsorption of MNZ was influenced by the solution pH, but was not significantly affected by the ionic strength and temperature. The adsorption of MNZ was enhanced when the MNZ solutions were prepared using wastewater. Therefore, the electrolytes present in the wastewater cooperated rather than competed with the MNZ molecules for the adsorption sites. Desorption equilibrium data of MNZ on all carbon materials demonstrated that the adsorption was reversible corroborating the weakness of the adsorbent-adsorbate interactions.
本工作研究了抗生素甲硝唑（MNZ）在活性炭（F400）、活性炭纤维（ACF）、介孔活性炭（CMK-3）和碳纳米管（MWCNT）上的吸附。分析了吸附剂-吸附质相互作用以及操作条件（离子强度、溶液 pH 值、温度、用 HNO3 处理对吸附剂的化学改性以及水基质）对吸附容量的影响，以证实吸附机制。吸附容量明显随碳材料的变化而变化，顺序为：F400>ACF>F400-HNO3>CMK-3>MWCNT>MWCNT-HNO3，不仅取决于它们的表面积和孔径分布，还取决于它们的化学性质。MNZ 的吸附受溶液 pH 值的影响，但受离子强度和温度的影响不大。当使用废水制备 MNZ 溶液时，MNZ 的吸附增强。因此，废水中存在的电解质与其说是与 MNZ 分子竞争吸附位，不如说是与 MNZ 分子协同作用。MNZ 在所有碳材料上的解吸平衡数据表明，吸附是可逆的，这证实了吸附剂-吸附质相互作用较弱。
