Earth Sciences Department, KFUPM, Dhahran 31261, Saudi Arabia.
Water Sci Technol. 2010;61(3):591-8. doi: 10.2166/wst.2010.897.
The removal of mercury (Hg(2+)) ions from contaminated water using multiwalled carbon nanotubes (MWCNTs) was investigated in this study. Results of the study showed that MWCNTs slurry was very efficient in removing as high as 1.0 mg/L of Hg(2+) from aqueous solutions via the adsorption mechanism. This removal efficiency was found to be a function of the aqueous pH level, dosage of CNTs, mixing rate, and contact time. The study showed that the Hg uptake by MWCNTs increased to 100% with an increase in pH from pH 4 to 8. The results also showed that higher dosage of MWCNTs, showed higher removal of Hg(2+). In a 50 mL water sample, 10 mg of MWCNTs was needed to remove all of the 0.1 mg/L of Hg(2+) ions. On the other hand, increasing the mixing rate from 50 to 150 rpm improved the removal efficiency. The experimental results also showed that mercury adsorption by MWCNTs follow a pseudo second-order reaction with a rate (k) of 0.018 and it is well described by the Langmuir isotherm model with maximum adsorptive capacity (q(max)) of 13.16.
本研究考察了多壁碳纳米管（MWCNTs）从受污染水中去除汞（Hg(2+)）离子的情况。研究结果表明，MWCNTs 悬浮液通过吸附机制非常有效地去除高达 1.0 mg/L 的 Hg(2+)水溶液。发现这种去除效率是水溶液 pH 值、CNTs 用量、混合速度和接触时间的函数。研究表明，随着 pH 值从 4 增加到 8，MWCNTs 对 Hg 的吸收率增加到 100%。结果还表明，MWCNTs 的用量越高，Hg(2+)的去除率越高。在 50 mL 水样中，需要 10 mg 的 MWCNTs 才能去除 0.1 mg/L 的所有 Hg(2+)离子。另一方面，将混合速度从 50 增加到 150 rpm 提高了去除效率。实验结果还表明，MWCNTs 对汞的吸附符合准二级反应，速率（k）为 0.018，并且很好地符合 Langmuir 等温吸附模型，最大吸附容量（q(max)）为 13.16。
