Exploring Phosphate Sorption on Thermally Modified Kaolinite

Abstract

The aim of this study is to investigate the capability and mechanism of phosphorus adsorption present in water through thermally treated kaolin. For this purpose, batch experiments are conducted to treat synthetic water samples with phosphate content using kaolin sourced from the northern region of Albania. The kinetics and mechanism of adsorption are examined. Experimental results indicated that a contact time of 3 hours achieves adsorption equilibrium, with the pseudo second-order model providing the best fit. Both Langmuir and Freundlich models describe the adsorption process, suggesting a combination of monolayer and multilayer adsorption. Furthermore, kaolin pre-treatment temperatures up to 500°C have minimal effect on adsorption capacity, apparently attributed to dehydration of bound water and densification of the clay structure.