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Enhanced adsorption of humic acids on ordered mesoporous carbon compared with microporous activated carbon
Author(s) -
Liu Fengling,
Xu Zhaoyi,
Wan Haiqin,
Wan Yuqiu,
Zheng Shourong,
Zhu Dongqiang
Publication year - 2011
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.450
Subject(s) - adsorption , microporous material , carbon fibers , activated carbon , mesoporous material , humic acid , phenol , chemistry , chemical engineering , size exclusion chromatography , graphite , organic chemistry , inorganic chemistry , materials science , catalysis , fertilizer , composite number , engineering , composite material , enzyme
Humic acids are ubiquitous in surface and underground waters and may pose potential risk to human health when present in drinking water sources. In this study, ordered mesoporous carbon was synthesized by means of a hard template method and further characterized by X‐ray diffraction, N 2 adsorption, transition electron microscopy, elemental analysis, and zeta‐potential measurement. Batch experiments were conducted to evaluate adsorption of two humic acids from coal and soil, respectively, on the synthesized carbon. For comparison, a commercial microporous activated carbon and nonporous graphite were included as additional adsorbents; moreover, phenol was adopted as a small probe adsorbate. Pore size distribution characterization showed that the synthesized carbon had ordered mesoporous structure, whereas the activated carbon was composed mainly of micropores with a much broader pore size distribution. Accordingly, adsorption of the two humic acids was substantially lower on the activated carbon than on the synthesized carbon, because of the size‐exclusion effect. In contrast, the synthesized carbon and activated carbon showed comparable adsorption for phenol when the size‐exclusion effect was not in operation. Additionally, we verified by size‐exclusion chromatography studies that the synthesized carbon exhibited greater adsorption for the large humic acid fraction than the activated carbon. The pH dependence of adsorption on the three carbonaceous adsorbents was also compared between the two test humic acids. The findings highlight the potential of using ordered mesoporous carbon as a superior adsorbent for the removal of humic acids. Environ. Toxicol. Chem. 2011; 30:793–800. © 2010 SETAC