Department of Chemical Engineering, University of Puerto Rico-Mayagüez Campus, Mayagüez 00681-9000, Puerto Rico.
Department of Chemistry, University of Puerto Rico-Mayagüez Campus, Mayagüez 00681-9000, Puerto Rico.
J Hazard Mater. 2016 Jul 15;312:262-271. doi: 10.1016/j.jhazmat.2016.03.073. Epub 2016 Mar 26.
Pillared clay based composites containing transition metals and a surfactant, namely MAlOr-NaBt (Bt=bentonite; Or=surfactant; M=Ni(2+), Cu(2+)or Co(2+)), were prepared to study selectivity and capacity toward single and multiple-component adsorption of bisphenol A (BPA) and 2,4-diclorophenol (DCP) from water. Tests were also performed to account for the presence of natural organic matter in the form of humic acid (HA). Equilibrium adsorption capacities for single components increased as follows: NaBt<Al-NaBt<AlOr-NaBt<MAlOr-NaBt. The observed equilibrium loadings were ca. 5 and 3mgg(-1) for BPA and DCP, respectively, at neutral pH conditions and ambient temperature, representing an ordered of magnitude increase over the unmodified pillared clay capacities. Inclusion of the transition metal brought an increase of nearly two-fold in adsorption capacity over the materials modified only with surfactant. The MAlOr-NaBt adsorbents displayed remarkable selectivity for BPA. Multi-component fixed-bed tests, however, revealed competition between the adsorbates, with the exception of the CuAlOr-NaBt beds. Inclusion of HA, surprisingly, enhanced the phenols adsorption capacity. Preliminary regeneration tests suggested that the adsorbent capacity can be recovered via thermal treatment or by washing with alkaline solutions. The former strategy, however, requires surfactant replenishment. More complex schemes would be needed to deal with absorbed HA.
制备了负载过渡金属和表面活性剂的层柱粘土复合材料 MAlOr-NaBt（Bt=膨润土；Or=表面活性剂；M=Ni(2+)、Cu(2+)或 Co(2+)），用于研究水中双酚 A（BPA）和 2,4-二氯苯酚（DCP）的单组分和多组分吸附的选择性和容量。还进行了测试，以说明以腐殖酸（HA）形式存在的天然有机物的存在。单组分的平衡吸附容量增加顺序如下：NaBt<Al-NaBt<AlOr-NaBt<MAlOr-NaBt。在中性 pH 值和环境温度条件下，BPA 和 DCP 的观察到的平衡负载量分别约为 5 和 3mg/g，与未改性的层柱粘土相比，增加了约一个数量级。过渡金属的加入使吸附容量相对于仅用表面活性剂改性的材料增加了近两倍。MAlOr-NaBt 吸附剂对 BPA 表现出显著的选择性。然而，多组分固定床测试表明，除了 CuAlOr-NaBt 床外，吸附剂之间存在竞争。令人惊讶的是，HA 的加入增强了酚类的吸附容量。初步的再生测试表明，可以通过热处理或用碱性溶液洗涤来回收吸附剂的容量。然而，前者策略需要表面活性剂的补充。需要更复杂的方案来处理吸附的 HA。
