Adsorption of humic acid onto chitin and chitosan

Abstract

The adsorption of humic acid onto chitin and chitosan has been investigated. The uptake of humic acid from aqueous solution was determined from changes in concentration, as measured by ultraviolet-visible spectroscopy. The decrease in humic acid removal was observed with the increase in pH. A significant uptake of humic acid on both chitin and chitosan was observed. The uptake of humic acid on chitosan was greater than that on chitin. Adsorption isothermal data could be interpreted by the Langmuir and Freundlich equation. Langmuir and Freundlich constants have been determined. The experimental data of the adsorption equilibrium from humic acid solutions correlate well with the Langmuir isotherm equation, as compared to the Freundlich isotherm equation. © 1998 John Wiley & Sons, Inc.