Removal of phosphate by adsorption onto oyster shell powder—kinetic studies

✍ Scribed by C Namasivayam; A Sakoda; M Suzuki

• Publisher: Wiley (John Wiley & Sons)
• Year: 2005
• Tongue: English
• Weight: 94 KB
• Volume: 80
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/jctb.1175

✦ Synopsis

Abstract

Kinetic studies on the removal of phosphate by adsorption onto oyster shell powder have been investigated at 24 °C. The results showed that the equilibrium occurred in 10 min and the equilibrium data followed the Freundlich isotherm. Freundlich constants were found to be k~f~, 1.4 × 10^−2^, and n, 0.71. The phosphate removal was not influenced by pH over the range 5.0–10.5. Continuous agitation studies at 24 °C and 530 rpm reached equilibrium after 7.7 days, when 24 g dm^−3^ of oyster shell powder reduced the phosphate concentration from 50 to 7.0 mg dm^−3^. The Lagergren rate constant for the slow adsorption process was observed to be 3.81 × 10^−4^ dm^3^ min^−1^. Comparison with calcium carbonate, GR grade, showed that oyster shell powder and CaCO~3~ behave more or less in the same way. Copyright © 2004 Society of Chemical Industry