二氧化锰改性碳纳米管对四环素和泰乐菌素的吸附

邓丽萍; 纪靓靓; 白朝暾

文章摘要

邓丽萍,纪靓靓,白朝暾.二氧化锰改性碳纳米管对四环素和泰乐菌素的吸附[J].农业环境科学学报,2015,34(4):781-786.

二氧化锰改性碳纳米管对四环素和泰乐菌素的吸附

Adsorption of Tetracycline and Tylosin on MnO₂ Coated Carbon Nanotubes

投稿时间：2014-11-07

DOI：10.11654/jaes.2015.04.025

中文关键词: 碳纳米管二氧化锰四环素泰乐菌素吸附

英文关键词: carbon nanotubes manganese dioxide tetracycline tylosin adsorption

基金项目:国家自然科学基金(41101479);中央高校基本科研业务费(2011B08814);中国博士后基金(2011M500849, 2012T50461)

作者	单位	E-mail
邓丽萍	河海大学浅水湖泊综合治理与资源开发教育部重点实验室, 南京 210098 河海大学环境学院, 南京 210098
纪靓靓	河海大学浅水湖泊综合治理与资源开发教育部重点实验室, 南京 210098 河海大学环境学院, 南京 210098	jill@hhu.edu.cn
白朝暾	河海大学浅水湖泊综合治理与资源开发教育部重点实验室, 南京 210098 河海大学环境学院, 南京 210098

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中文摘要:

采用氧化还原法制备二氧化锰负载碳纳米管(MnO₂/MWNT),通过批次吸附实验研究其对所选四环素和泰乐菌素的吸附行为及其影响因素。研究结果表明:与未处理的碳纳米管相比,二氧化锰负载后显著提高了碳纳米管对四环素和泰乐菌素的吸附,约提高了5~8倍;两种抗生素在MnO₂/MWNT上的强吸附机制可解释为π-π电子交互作用、阳离子-π键作用和路易斯酸碱对作用;随着pH升高,四环素和泰乐菌素在MnO₂/MWNT上的吸附显著降低,两种抗生素所含官能团的去质子化作用,以及MnO₂/MWNT表面含氧官能团的解离,导致MnO₂/MWNT与两种抗生素之间的吸附作用减弱。可溶性腐植酸降低了泰乐菌素在MnO₂/MWNT上的吸附,而对四环素影响很小,主要原因是大分子腐植酸不能有效地与四环素竞争MnO₂/MWNT孔道内部的吸附位点。

英文摘要:

Carbon nanotubes have strong adsorption affinities to organic pollutants in water due to their large and hydrophobic surface areas. However, carbon nanotubes are easy to flocculate. Here we studied the adsorption behaviors of two typical pharmaceutical antibiotics(tetracycline and tylosin) on multi-walled carbon nanotubes coated with manganese dioxide(MnO₂/MWNT). MnO₂/MWNT showed extraordinarily high adsorption affinity to both antibiotics. Adsorption of tetracycline and tylosin by MnO₂/MWNT enhanced 5~8 times, compared to MWNT alone. This enhanced adsorption of tetracycline and tylosin by MnO₂/MWNT was due to strong interactions(π-π electron-donor-acceptor interactions, cation-π bonding and Lewis acid-base interaction) with the graphene surface of MnO₂/MWNT. Similar pH-dependent adsorption was observed in tetracycline and tylosin. When pH was increased from 3 to 11, adsorption coefficient decreased significantly. Increasing pH facilitated deprotonation of charged amino group and protonated enol groups, hence weakening the cation-π bonding, π-π EDA interaction and Lewis acid-base interaction between antibiotics and MnO₂/MWNT. The presence of humic acids prominently suppressed tylosin adsorption on MnO₂/MWNT, but only slightly affected tetracycline adsorption on MnO₂/MWNT. This was because relatively large humic acid could not effectively compete adsorption sites with relatively small tetracycline on MnO₂/MWNT.

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