9-
Degradation of Azure – B
by sonochemical treatment
Chetna Panwar, Anil Kumar, Mukesh Paliwal, Pinki B. Punjabi and Suresh
C. Ameta*
Department of Chemistry, University
College
of
Science,
Mohanlal
Sukhadia
University,
Udaipur, Rajasthan –313 001, India,
e-mail:
anilchohadia@yahoo.co.in
*e-mail:
ameta_sc@yahoo.com
Abstract
This investigation describes a sonochemical
treatment which has been developed for the degradation of azure - B
dye. Ultrasonic frequency of 4 MHz was used for all experiments in
order to find the best conditions for degradation. The effects of
various parameters like pH, concentration of dye, solvent composition,
temperature, nature and concentration of surfactant etc. on the
reaction rate have been examined. The progress of the sonochemical
degradation was monitored by spectrophotometry. The value of energy of
activation was also computed for sonochemical degradation. It was
observed that the dye was completely oxidized and degraded into CO2
and H2O through a two step mechanism. First step was found
to faster (k = 7.19 x 10-4 s-1as compare to
second step k = 1.12 x 10-4 s-1) 80% degradation
of dye taken place in first step. A suitable tentative mechanism has
also been proposed.
Key
words:
Sonochemical
degradation, Azure – B, surfactant,
spectrophotometry
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