Adsorption of zinc ion on leonardite prepared from coal waste

Abstract

Naturally occurring leonardite, obtained from Mae Moh mine lignite, has been tested as a potential sorbent for Zn2+. The factors that affect to the sorption, such as pH, contact time and the adsorption isotherm were also investigated. The high performance of Zn2+removal was demonstrated at pH values of 5-6. Batch experiment showed that the equilibrium was reached after 180 min. The sorption data were correlated with the Langmuir and Freundlich adsorption models. The average maximum adsorption capacity was found to be 0.141 mmol g-1. Moreover, the equilibrium parameter, KR indicated the favor ability of leonardite for adsorbed Zn2+.