The ability of enzymes to decolourise various azo dyes has been tested by several researchers in the past.
The present study explores the potential of crude peroxidase from horseradish to decolourise representative monoazo and diazo dyes, MO and BB, respectively.
Microorganisms like Staphylococcus have been shown to oxidatively decolourise (at least 97 %) solutions of azo dyes like direct blue 71 and reactive yellow 107 (Franciscon et al. 2009).
It has been found that cysteine, glutathione, ascorbic acid, tocopherol, polyhydroxy aromatic compounds (hydroquinone, pyrogallol, etc)., and aromatic amines (p-phenylene diamine, p-aminophenol etc)., reduce and decolourise DPPH by their hydrogen donating ability [26].
Horseradish peroxidase obtained from fresh tubers of the horseradish plant and partially purified by dialysis was shown to successfully decolourise the monoazo dye direct yellow (Maddhinni et al. 2006) in synthetic waste water.
In the present study, the extracts of C. pallida stem were able to decolourise DPPH and the free radical scavenging potentials of the extracts were found to be in order of PEE > ME > CE > AE.
The present study is an attempt to assess on a laboratory scale the potential of crude HRP to decolourise monoazo and diazo dyes using MO and BB as respective representatives.
The three technologies are able to successfully decolourise the wastes during the first stages, which means that the breakage of the azoic group is one of the first steps in the oxidation mechanisms.
This is most likely due to the excellent scattering properties with SBA-15 allowing for a much higher rate of electron-hole generation that is significantly greater than the recombination rate and thus allowing for more active species being produced to decolourise the MB.
COD, HPLC, UV vis and potential control measurements were also used to verify the viability of these anodes to degrade and decolourise wastewater solutions containing a reactive dye: C.I. Reactive Orange 4. With this purpose, different oxido-reduction electrolyses were carried out in presence of either 0.1 M Na2SO4 or 0.1 M NaCl as electrolyte.
Attempts to prevent this with the addition of bovine serum albumin made smears difficult to decolourise, and the practice was discontinued.
