Effects of copper, lead, and cadmium on the sorption of 2,4,6-trichlorophenol onto and desorption from wheat ash and two commercial humic acids.
Effects of copper, lead, and cadmium on the sorption of 2,4,6-trichlorophenol onto and desorption from wheat ash and two commercial humic acids.
复制标题
DOI：
10.1021/es803357b
复制
发表时间：
2009-07
影响因子：
11.4
通讯作者：
Yu-Sheng Wang;X. Shan;M. Feng;Guangcai Chen;Zhiguo Pei;B. Wen;Taozhe Liu;Ya‐ning Xie;G. Owens
中科院分区：
文献类型：
--
作者：
Yu-Sheng Wang;X. Shan;M. Feng;Guangcai Chen;Zhiguo Pei;B. Wen;Taozhe Liu;Ya‐ning Xie;G. Owens
研究了Cu ~（2+）、Pb ~（2+）、Cd ~（2+）对麦灰和两种商品腐殖酸吸附和解吸2，4，6-三氯苯酚（TCP）的影响。Cu和Pb ~（2+）降低了TCP在所有吸附剂上的吸附，使TCP在煤灰和德国腐殖酸（GeHA）上的解吸滞后较小，而在天津腐殖酸（TJHA）上的解吸滞后较大。镉对TCP的吸附和解吸影响不大。傅里叶变换红外光谱（FTIR）和X射线吸收光谱（XAS）结合荧光猝灭研究提供了对TCP吸附和解吸机制的见解，受到Cu 2+和Pb 2+的影响，表明Cu 2+和Pb 2+的络合可能是通过灰分、TJHA和GeHA的羧基、羟基和酚基，并且这些相同的官能团在吸附过程中也与TCP反应。相反，镉，一种“软酸”，对TCP的吸附没有影响。吸附的Cu 2+和Pb 2+离子周围的致密水的水合壳也可以与TCP竞争可用的表面积。芘的荧光猝灭验证了对于TJHA，Cu 2+和Pb 2+促进形成超分子缔合，内部疏水区域通过外部亲水层与水环境分离。
The effects of copper (Cu2+), lead (Pb2+), and cadmium (Cd2+) on the sorption of 2,4,6-trichlorophenol (TCP) to and desorption from wheat ash and two commercial humic acids were studied. Copper and Pb2+ diminished the sorption of TCP onto all adsorbents, and made desorption of TCP less hysteretic from ash and German humic acids (GeHA), but more hysteretic from Tianjin humic acids (TJHA). Cadmium had little effect on TCP sorption and desorption. Fourier-transform infra red (FTIR) and X-ray absorption spectroscopy (XAS) in conjunction with fluorescence quenching studies provided insights into the mechanisms of TCP sorption and desorption as affected by Cu2+ and Pb2+, indicating that complexation of Cu2+ and Pb2+ was likely via carboxylic, hydroxylic and phenolic groups of ash, TJHA and GeHA, and that theses same functional groups also reacted with TCP during sorption. In contrast, Cd, a "soft acid", had no effect on the adsorption of TCP. Hydration shells of dense water around adsorbed Cu2+ and Pb2+ ions may also compete with TCP for available surface area. Fluorescence quenching of pyrene verified that for TJHA, Cu2+ and Pb2+ promoted the formation of supramolecular associations with interior hydrophobic regions separated from aqueous surroundings by exterior hydrophilic layers.