Mihara Yoshihiro, Zhang Sijing, Syahputra Rudy, Akemoto Yasuhiro, Itoh Shinji, Tanaka Shunitz
Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, Hokkaido University of Science, Sapporo, Hokkaido, 006-8590, Japan.
Division of Environmental Science Development, Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan.
Anal Sci. 2020 May 10;36(5):553-557. doi: 10.2116/analsci.19SBP06. Epub 2020 Mar 6.
Microspheres of aluminosilicate glass from volcanic sediment, whose surfaces were modified with functional groups, Shirasu-balloons (SB), were investigated as an adsorbent to remove cadmium ions from contaminated soil. The introduction of thiol groups (-SH) on the surface of SB enabled it to adsorb cadmium ions. Meanwhile, the introduction of an alkyl group (-ODS) made the surface of SB hydrophobic, and consequently increased the mechanical strength of SB. Those adsorbents could float up on the water surface after the adsorption process. The prepared adsorbent was characterized by FTIR spectrophotometry, elemental analysis and optical microscopy for making photographic images. The adsorption of cadmium ions on the adsorbent was investigated by comparing the results by a plain SB with those by thiol-functionalized SB. The adsorption maximum for cadmium ions was 3.75 mg/g for SH-SB and 2.62 mg/g for SH-ODS-SB, respectively. The adsorption of cadmium ions on functionalized SH-SB and SH-ODS-SB fitted well to the Langmuir isotherm equation. After a shaking time of 24 h, the recovering ratios of the absorbents from soil were 73 wt% for SH-SB and 98 wt% for SH-ODS-SB absorbents. In addition, the kinetic and adsorption-desorption properties of the adsorbent were also considered.
对来自火山沉积物的表面用官能团修饰的硅铝酸盐玻璃微球——白榴火山灰球（SB）进行了研究，以考察其作为从污染土壤中去除镉离子的吸附剂的性能。在SB表面引入硫醇基（-SH）使其能够吸附镉离子。同时，引入烷基（-ODS）使SB表面具有疏水性，从而提高了SB的机械强度。这些吸附剂在吸附过程后能够漂浮在水面上。通过傅里叶变换红外光谱法、元素分析和光学显微镜对制备的吸附剂进行表征以获取照片图像。通过比较普通SB与硫醇官能化SB对镉离子的吸附结果，研究了吸附剂对镉离子的吸附情况。硫醇化SB对镉离子的最大吸附量为3.75 mg/g，硫醇-ODS化SB对镉离子的最大吸附量为2.62 mg/g。镉离子在官能化的硫醇化SB和硫醇-ODS化SB上的吸附很好地符合朗缪尔等温方程。振荡24小时后，从土壤中回收的吸附剂回收率分别为：硫醇化SB为73 wt%，硫醇-ODS化SB为98 wt%。此外，还考虑了吸附剂的动力学和吸附-解吸性能。
