Influence of hydrolysis reactions on vanadium(V) adsorption using chitosan

摘要

Chitosan is very efficient at removing vanadium from dilute solutions: adsorption capacity reaches 400-450 mg V g~(-1) (8-9 mmol V g~(-1)). The optimum adsorption occurs at pH 3: both the sorption capacity and the affinity for vanadium are maximum. In acidic solutions, amine groups of chitosan are protonated and vanadate anions are adsorbed through ionic interactions. The comparison of speciation diagrams and sorption isotherms indicates that decavanadate species are the most favorable species for adsorption on chitosan among the twelve species of vanadium that were identified.