College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
College of Environment and Safety, Taiyuan University of Science and Technology, Taiyuan, 030024, China.
Environ Sci Pollut Res Int. 2019 Apr;26(10):10263-10273. doi: 10.1007/s11356-019-04218-x. Epub 2019 Feb 13.
Effective removal of dyes has been widely investigated by the adsorption of powder activated carbon and photodegradation by titanate nanotubes (TNTs). In this study, a facile one-step alkaline-hydrothermal method was applied to synthesize powder activated charcoal-supported TNTs (TNTs@PAC). Adsorption of three representative dyes, i.e., cationic methylene blue (MB), cationic rhodamine B (RhB), and anionic methyl orange (MO), onto TNTs@PAC was evaluated by the adsorption kinetic experiments and adsorption isotherms. The first 30 min is the main time phase of adsorption, and MB, RhB, and MO obtained the experimental equilibrium uptake of 173.30, 115.06, and 106.85 mg/g, respectively, indicating their final removal efficiencies of 100%, 69.36%, and 64.11%, respectively. The increase of pH value reduced adsorption capacity of MO (from 149.35 mg/g at pH of 2 to 96.99 mg/g at pH of 10), but facilitated MB adsorption, which was attributed to the charge distribution on the surface of TNTs@PAC and the charge of dyes at different pH. Furthermore, good capacity recoveries of MB by TNTs@PAC (> 99%) were observed after UV irradiation treatment, indicating the used TNTs@PAC can be easily recycled for the adsorption of MB by UV irradiation. Overall, TNTs@PAC is an effective process for remediation of dye-contaminated water because of its adsorption performance for all selected dyes and good regeneration capacity for MB.
粉末状活性炭的吸附和钛酸盐纳米管（TNTs）的光降解已被广泛研究用于有效去除染料。在本研究中，采用简便的一步碱性水热法合成了粉末状活性炭负载的 TNTs（TNTs@PAC）。通过吸附动力学实验和吸附等温线评估了 TNTs@PAC 对三种代表性染料，即阳离子亚甲蓝（MB）、阳离子罗丹明 B（RhB）和阴离子甲基橙（MO）的吸附性能。前 30 分钟是吸附的主要时间阶段，MB、RhB 和 MO 的实验平衡吸附量分别为 173.30、115.06 和 106.85mg/g，表明它们的最终去除效率分别为 100%、69.36%和 64.11%。pH 值的增加降低了 MO 的吸附容量（从 pH 值为 2 时的 149.35mg/g 降低到 pH 值为 10 时的 96.99mg/g），但有利于 MB 的吸附，这归因于 TNTs@PAC 表面的电荷分布和不同 pH 值下染料的电荷。此外，TNTs@PAC 对 MB 具有良好的容量回收率（>99%），经过 UV 照射处理后可以回收，表明用过的 TNTs@PAC 可以通过 UV 照射很容易地回收用于 MB 的吸附。总体而言，由于对所有选定染料具有吸附性能和对 MB 良好的再生能力，TNTs@PAC 是一种有效修复染料污染水的方法。
