
449Application of Green Catalysis and Processes
The raising of the temperature of the reaction mixture to 80°C from ambient temperature
takes about 25 min. The condenser prevents loss of vapour and magnetic stirrer agitates the
mixture. Hydrogen peroxide and iron-exchanged catalyst of known quantities are added
to the dye solution and the reaction is carried out at 80°C; samples are taken at periodic
intervals. The samples after collection are raised to pH 11 by adding 0.1 N NaOH (so that
no further reaction takes place) and the residual hydrogen peroxide is removed by adding
MnO
2
, which catalyses the decomposition of peroxide to water and oxy ...