Abstract

Octolig, a commercially available (a polyethylene diamine covalently attached to silica gel), was subjected to modifications to incorporate sulfur for enhanced removal of lead ion from aqueous solutions. The basic approach was attempted formation of “ThioOctolig” by the reaction of Octolig with thioacetamide in toluene using a shaker bath for 24 or 48 h or in the presence of 10% HCl (1 h). Our experience was that conversion was limited to about 20% based on sulfur analysis for 24 or 48 h reaction time, or in the presence of 10% HCl. In fact, with acidification, the results were poorer. Duplicate runs indicated consistent results. Literature reported that SbCl₃ was an effective catalyst with a reaction time of 1 h. Use of this reagent (1-h reaction time) produced a bright orange red product, in contrast with previous yellow-colored products. A control run indicated that this reagent reacted with Octolig in toluene (in the dark) to produce a red-colored sample; thioacetamide reacted to produce a yellow sample. Use of SbCl₃ (∼5 mole %) did not enhance the sulfur content of Octolig. A sample of Octolig removed 68% lead ion from a 120 ppm aqueous lead while a sample of ThioOctolig (10% S) removed 99.4% lead ions. We also investigated enhancing the sulfur incorporation upon raising the reaction temperature with thioacetamide.

摘要

对可商购的Octolig（与硅胶共价连接的聚乙烯二胺）进行了改性，以掺入硫以增强从水溶液中去除铅离子的能力。基本方法是尝试通过摇床使Octolig与硫代乙酰胺在甲苯中使用摇动浴反应24或48 h或在10％HCl的存在下（1 h）来形成“噻吩基”。我们的经验是，基于24或48小时反应时间或10％HCl存在下的硫分析，转化率限制在20％左右。实际上，酸化后的结果较差。重复运行表明结果一致。文献报道SbCl ₃是一种有效的催化剂，反应时间为1小时。与以前的黄色产品相比，使用该试剂（反应时间为1小时）可产生亮橙色红色产品。对照实验表明，该试剂与Octolig在甲苯中（在黑暗中）反应生成红色样品。硫代乙酰胺反应生成黄色样品。使用SbCl ₃（〜5摩尔％）不会增加Octolig的硫含量。Octolig样品从120 ppm铅水溶液中去除了68％的铅离子，而ThioOctolig（10％S）样品去除了99.4％的铅离子。我们还研究了在提高与硫代乙酰胺的反应温度后提高硫的掺入量。