کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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611740 | 880684 | 2008 | 7 صفحه PDF | دانلود رایگان |
Heavy metal contamination of waters and soils is particularly dangerous to the living organisms. Different studies have demonstrated that hydroxyapatite has a high removal capacity for divalent heavy metal ions in contaminated waters and soils. The removal of Cd from aqueous solutions by hydroxyapatite was investigated in batch conditions at 25±2°C. Cadmium was applied both as single- or multi-metal (Cd+Pb+Zn+CuCd+Pb+Zn+Cu) systems with initial concentrations from 0 to 8 mmol L−1. The adsorption capacity of hydroxyapatite in single-metal system ranged from 0.058 to 1.681 mmol of Cd/g of hydroxyapatite. In the multi-metal system competitive metal sorption reduced the removal capacity by 63–83% compared to the single-metal system. The sorption of Cd by hydroxyapatite follows the Langmuir model. Cadmium immobilization occurs through a two-step mechanism: rapid surface complexation followed by partial dissolution of hydroxyapatite and ion exchange with Ca resulting in the formation of a cadmium-containing hydroxyapatite.
The sorption of Cd by hydroxyapatite occurs through a two-step mechanism: rapid surface complexation followed by partial dissolution of hydroxyapatite and ion exchange with Ca.Figure optionsDownload as PowerPoint slide
Journal: Journal of Colloid and Interface Science - Volume 317, Issue 2, 15 January 2008, Pages 402–408