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论文类型：期刊论文

发表时间：2014-01-21

发表刊物：PLOS ONE

收录刊物：SCIE、PubMed、Scopus

卷号：9

期号：1

页面范围：e86228

ISSN号：1932-6203

摘要：Effects of pH on adsorption and removal efficiency of ionizable organic compounds (IOCs) by environmental adsorbents are an area of debate, because of its dual mediation towards adsorbents and adsorbate. Here, we probe the pH-dependent adsorption of ionizable antibiotic oxytetracycline (comprising OTCH2+, OTCH +/-, OTC-, and OTC2-) onto cyclodextrin polymers (CDPs) with the nature of molecular recognition and pH inertness. OTCH +/- commonly has high adsorption affinity, OTC- exhibits moderate affinity, and the other two species have negligible affinity. These species are evidenced to selectively interact with structural units (e. g., CD cavity, pore channel, and network) of the polymers and thus immobilized onto the adsorbents to different extents. The differences in adsorption affinity and mechanisms of the species account for the pH-dependent adsorption of OTC. The mathematical equations are derived from the multiple linear regression (MLR) analysis of quantitatively relating adsorption affinity of OTC at varying pH to adsorbent properties. A combination of the MLR analysis for OTC and molecular recognition of adsorption of the species illustrates the nature of the pH-dependent adsorption of OTC. Based on this finding, gamma-HP-CDP is chosen to adsorb and remove OTC at pH 5.0 and 7.0, showing high removal efficiency and strong resistance to the interference of coexisting components.