Abstract:
World production of dyes reaches more than 700,000 tons per year. This number will
continue to increase with the increasing number of applications of dyes in various products
such as cosmetics, printing, textiles, paper and other industries. In the coloring process only
85% of the dye is used and the remaining 15% is wasted as waste. Dyestuff waste that is
discharged into the environment without further processing is toxic with potential
carcinogenic and genotoxic effects. The dye that is often used in the textile industry is
methylene blue (MB) because it is cheap and easy to obtain. The chemical method based on
the Fenton reaction can rapidly degrade organic compounds into harmless products such as
CO2 and H2O using highly reactive radicals such as OH•. The MnO2-bentonite composite in
this study was synthesized to be a catalyst that decomposes H2O2 into radicals. This
composite was successfully obtained after dispersing cryptomelane which was synthesized
from the reduction of KMnO4 by citric acid through the reflux method (mole ratio 3:1). This
MnO2-bentonite composite was used as a heterogeneous Fenton by activating H2O2 into OH
radical on the surface of bentonite. Variations of reaction parameters such as photocatalyst
and H2O2 volume were used to optimize MB degradation. Based on the research that has been
done, the percentage of degradation is 97.643% through photocatalyst, with a variation
volume of H2O2 as much as 5 mL the percentage of degradation is 91,616 %.
