Open AccessComparative Study on the Decolorization of Orange II by Zero-valence Tin in Citric and Hydrochloric Acids
Author(s) -
Shizuo Nishide,
Makoto Shoda
Publication year - 2012
Publication title -
energy and environment research
Language(s) - English
Resource type - Journals
eISSN - 1927-0577
pISSN - 1927-0569
DOI - 10.5539/eer.v2n1p1
Subject(s) - hydrochloric acid , citric acid , tin , orange (colour) , chemistry , valence (chemistry) , inorganic chemistry , nuclear chemistry , dissolution , organic chemistry , food science
Zero-valence tin reductively degraded a persistent azo dye, Orange II to produce colorless aromatic amines. The effects of acid concentrations and initial Orange II concentrations on the decolorization of Orange II by tin in citric and hydrochloric acids were investigated. The decolorization reaction in citric acid was faster than that in hydrochloric acid at 2.5 and 5 mM acid concentrations. The faster reaction would be related to the characteristic dissolution reaction of tin in citric acid. The first-order kinetic was applicable in citric acid over the examined range of 0.1 - 0.4 mM initial Orange II. However, at more than 0.2 mM initial Orange II the first-order kinetic was not applicable in hydrochloric acid and thus the relaxation first-order reaction kinetic was applied. The result that zero-valence-tin/citric acid system demonstrated successful decolorization in repeated use supports the possibility of its application for azo dye wastewater