%0 Journal Article
%T Electrochemical Synthesis of Nitro-Chitosan and Its Performance in Chromium Removal
%A Prashant K. Jha
%A Gary P. Halada
%A Scott M. McLennan
%J Coatings
%D 2013
%I MDPI AG
%R 10.3390/coatings3030140
%X A synthesized polymeric form of chitosan, electrochemically precipitated and photochemically modified, has been found to have significant value in removal of toxic chromate oxyanions from solution. Fourier Transform Infra-Red (FTIR), Raman and X-ray photoelectron spectroscopy (XPS) indicated that a significant percentage of the amine functional groups were oxidized to nitro groups as a result of reactions with hydroxyl ions formed in the electrochemical process with additional oxidation occurring as a result of exposure to ultra-violet light. The adsorption capacity of the modified chitosan for chromate was investigated in a batch system by taking into account effects of initial concentration, pH of the solution and contact time. Nitro-chitosan showed greater adsorption capacity towards Cr (VI) than other forms of chitosan, with a maximum adsorption of 173 mg/g. It was found that pH 3 is the optimum for adsorption, a Langmuir model is the best fit for the adsorption isotherm, and the kinetics of reaction followed a pseudo second order function. Overall, our results indicate that electrochemical modification of chitosan is an effective method to enhance the reactivity of chitosan towards metals.
%K chitosan
%K nitro-chitosan
%K electrochemical
%U http://www.mdpi.com/2079-6412/3/3/140