Department of Civil and Environmental Engineering, University of Houston , Houston, Texas 77204-4003, United States.
Environ Sci Technol. 2014 Sep 2;48(17):10372-9. doi: 10.1021/es502647n. Epub 2014 Aug 20.
Interest in incorporating nanomaterials into water treatment technologies is steadily growing, driving the necessity to understand the interaction of these new materials with specific water contaminants. In the present study, five different carbonaceous materials: activated carbon (AC), charcoal (BC), carbon nanotubes (CNT), graphene (GE), and graphene oxide (GO) were investigated as sorbent materials for 11 polychlorinated biphenyl (PCB) congeners in aqueous concentrations in the pg-μg/L range. Sorbent-water distribution coefficients (Ks) calculated in aqueous concentrations of ng/L show that AC is superior to GE, GO, CNT, and BC for the 11 PCB congeners investigated by an average of 1.1, 1.1, 1.3, and 2.5 orders of magnitude, respectively. Additionally, maximum capacity and sorption affinity parameters from the Langmuir, Freundlich, and Polanyi-Dubinin-Manes (PDM) models show a similar result. Interestingly, however, the effect of molecular planarity has greater impact on PCB sorption to the nanomaterials, such that the planar congeners form stronger bonds with CNT, GE, and GO compared to AC and BC. This work demonstrated superior PCB sorption by AC as compared with the nanomaterials examined such that substantial post production modifications would be necessary for the nanomaterials to out-perform AC.
人们对将纳米材料纳入水处理技术的兴趣日益浓厚，这促使人们有必要了解这些新材料与特定水污染物的相互作用。在本研究中，研究了五种不同的碳质材料：活性炭（AC）、木炭（BC）、碳纳米管（CNT）、石墨烯（GE）和氧化石墨烯（GO），作为吸附剂材料，用于吸附 pg-μg/L 浓度范围内水中的 11 种多氯联苯（PCB）同系物。在 ng/L 水浓度下计算的吸附剂-水分配系数（Ks）表明，AC 对所研究的 11 种 PCB 同系物的吸附性能优于 GE、GO、CNT 和 BC，平均分别高出 1.1、1.1、1.3 和 2.5 个数量级。此外，从 Langmuir、Freundlich 和 Polanyi-Dubinin-Manes（PDM）模型得出的最大容量和吸附亲和力参数也得出了类似的结果。然而，有趣的是，分子平面性对 PCB 与纳米材料的吸附的影响更大，使得平面同系物与 CNT、GE 和 GO 形成比 AC 和 BC 更强的键。这项工作表明，与所研究的纳米材料相比，AC 对 PCB 的吸附性能更好，因此需要对纳米材料进行大量的后生产改性，才能使其性能优于 AC。
