| 聚硫代酰胺修饰活性炭对Au(Ⅲ)的选择性吸附效果与机制 |
| 摘要点击 3118 全文点击 1071 投稿时间：2021-06-23 修订日期：2021-08-13 |
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| 中文关键词 聚硫代酰胺修饰活性炭 金(Au) 吸附 选择性 吸附机制 |
| 英文关键词 polythioamides modified activated carbon gold (Au) adsorption selectivity adsorption mechanism |
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| 中文摘要 |
| 通过在活性炭（AC）上原位合成聚硫代酰胺（PTA），成功制备了一种聚硫代酰胺修饰的活性炭基吸附材料（AC-PTA），研究其对废水中三价金[Au（Ⅲ）]的选择性吸附效果及机制.结果表明，AC-PTA在较宽的pH范围（<5.0）内对多金属离子共存溶液中的Au（Ⅲ）表现出优异的选择性吸附性能，Au（Ⅲ）的剩余浓度小于0.1 mg·L-1，其它金属离子几乎未被吸附；在pH 2~3时对Au（Ⅲ）的吸附效果最好；对Au（Ⅲ）的选择性吸附动力学过程符合伪二级动力学模型（R2=0.9853），热力学过程符合Langmuir吸附等温线模型（R2=0.9936），吸附容量最高可达2018 mg·g-1.AC-PTA对Au（Ⅲ）优异的选择性吸附性能主要归因于AC-PTA表面官能团-C（[FY=，1]S）NH-与Au（Ⅲ）的配位作用、带正电的AC-PTA与Au（Ⅲ）络合态阴离子之间的静电吸附作用以及AC对Au（Ⅲ）的直接还原作用.最后将吸附后的AC-PTA在空气条件下1000℃灼烧4 h，得到质量分数为90.0%的固态金，实现了金的高效回收，为实际废水中低浓度Au（Ⅲ）的选择性吸附与回收提供了技术支撑. |
| 英文摘要 |
| By using in-situ synthesis of polythioamide (PTA) on activated carbon (AC), a polythioamide-modified activated carbon-based adsorbent (AC-PTA) was successfully prepared and used to study the selective adsorption effect and mechanism of Au(Ⅲ) in wastewater. The results showed that AC-PTA exhibited excellent selective adsorption to Au(Ⅲ) in the coexisting solution of multiple metal ions in a wide pH range (<5.0). The adsorption effect for Au(Ⅲ) was the best at a pH of 2 and 3; the concentration of residue Au(Ⅲ) was less than 0.1 mg·L-1, whereas other metals were barely adsorbed. The selective adsorption process for Au(Ⅲ) conformed to the pseudo-second kinetic model (R2=0.9853), the thermodynamic process conformed to the Langmuir isotherm process (R2=0.9936), and adsorption capacity was up to 2018 mg·g-1. Such advantages were mainly attributed to the coordination interaction between the -C([FY=,1]S)NH- functional groups on the AC-PTA surface and Au(Ⅲ), the electrostatic adsorption between the positive AC-PTA and negative Au(Ⅲ) complex anions, and the direct reduction of Au(Ⅲ) by AC. The successful recovery of gold was finally realized by burning the adsorbed AC-PTA at 1000℃ for 4 hours under air conditions, and solid gold with a mass fraction higher than 90.0% was obtained. This study provided the possibility for selective adsorption and recovery of low concentration Au(Ⅲ) from actual wastewater. |
