Branched Polymeric Media: Perchlorate-Selective Resins from Hyperbranched Polyethyleneimine
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- 作者：Dennis P. Chen ; Changjun Yu ; Ching-Yu Chang ; Yanjian Wan ; Jean M. J. Frechet ; William A. Goddard ; III ; Mamadou S. Diallo
- 刊名：Environmental Science & Technology (ES&T)
- 出版年：2012
- 出版时间：October 2, 2012
- 年：2012
- 卷：46
- 期：19
- 页码：10718-10726
- 全文大小：397K
- 年卷期：v.46,no.19(October 2, 2012)
- ISSN：1520-5851
文摘
Perchlorate (ClO4鈥?/sup>) is a persistent contaminant found in drinking groundwater sources in the United States. Ion exchange (IX) with selective and disposable resins based on cross-linked styrene divinylbenzene (STY-DVB) beads is currently the most commonly utilized process for removing low concentrations of ClO4鈥?/sup> (10鈥?00 ppb) from contaminated drinking water sources. However, due to the low exchange capacity of perchlorate-selective STY-DVB resins (0.5鈥?.8 eq/L), the overall cost becomes prohibitive when treating groundwater with higher concentration of ClO4鈥?/sup> (e.g., 100鈥?000 ppb). In this article, we describe a new perchlorate-selective resin with high exchange capacity. This new resin was prepared by alkylation of branched polyethyleneimine (PEI) beads obtained from an inverse suspension polymerization process. Batch and column studies show that our new PEI resin with mixed hexyl/ethyl quaternary ammonium chloride exchange sites can selectively extract trace amounts of ClO4鈥?/sup> from a makeup groundwater (to below detection limit) in the presence of competing ions. In addition, this resin has a strong-base exchange capacity of 1.4 eq/L, which is 1.75鈥?.33 times larger than those of commercial perchlorate-selective STY-DVB resins. The overall results of our studies suggest that branched PEI beads provide versatile and promising building blocks for the preparation of perchlorate-selective resins with high exchange capacity.