College of Chemistry and Chemical Engineering, Shaoxing University, Zhejiang 312000, PR China.
Sci Total Environ. 2011 Jan 1;409(3):625-30. doi: 10.1016/j.scitotenv.2010.10.015. Epub 2010 Nov 18.
The organobentonite (CTMA-Bent) was prepared from Na(+)-saturated bentonite (Na-Bent) by intercalation with cetyltrimethylammonium bromide (CTMA), and used as a carrier of nanoscale zero valent iron (NZVI) for the removal of atrazine. The NZVI/CTMA-Bent composite was characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM), and good dispersion of nanoscale iron particles on the carrier was observed. The removal efficiency of atrazine by this composite was compared with that by commercial iron powder and NZVI itself. For both treatments by NZVI and NZVI/CTMA-Bent, the removal efficiency increased as the pH of the solution decreased, and the removal percentage of atrazine by NZVI/CTMA-Bent reached 63.5% at initial pH=5.0 after 120 min. It is not only much higher than that (26.6%) by NZVI containing the same amount of iron, but also superior to the sum (32.1%) of reduction by NZVI plus adsorption by CTMA-Bent (5.5%). Besides, the NZVI/CTMA-Bent has a good long-term stability, and the carrier CTMA-Bent could prevent the iron ions (the byproduct of dechlorination) from leaching into the solution.
有机膨润土（CTMA-Bent）是由季铵盐十六烷基三甲基溴化铵（CTMA）插层钠基膨润土（Na-Bent）制备而成，用作纳米零价铁（NZVI）的载体，用于去除莠去津。通过 X 射线衍射（XRD）和透射电子显微镜（TEM）对 NZVI/CTMA-Bent 复合材料进行了表征，观察到纳米铁颗粒在载体上的良好分散。将该复合材料去除莠去津的效率与商用铁粉和 NZVI 本身进行了比较。对于 NZVI 和 NZVI/CTMA-Bent 的两种处理方式，去除效率随着溶液 pH 值的降低而增加，在初始 pH=5.0 下，经过 120min，NZVI/CTMA-Bent 对莠去津的去除率达到 63.5%。这不仅远高于含有相同量铁的 NZVI（26.6%）的去除率，而且优于 NZVI 还原（32.1%）加上 CTMA-Bent 吸附（5.5%）的总和。此外，NZVI/CTMA-Bent 具有良好的长期稳定性，载体 CTMA-Bent 可以防止铁离子（脱氯的副产物）浸出到溶液中。
