Degradation of crystal violet (CV) from aqueous solutions using ozone, peroxone, electroperoxone, and electrolysis processes: a comparison study

Abstract

In this study, the degradation of crystal violet (CV) was investigated by different oxidation processes; ozone (OZ), peroxone (PO), electrolysis (E), electrolysis/H2O2 (ECP), electroperoxone (EPO), and electrolysis/peroxene/H2O2 (EPOP). Main parameters including contact time, pH, CV concentration, and effect of scavengers were studied. The results showed that all processes were capable of CV decolorization. Among these processes, peroxone and electrolysis/peroxene/H2O2 with efficiency about > 90% were more effective than other ones. A significant decrease in oxidation rate of CV was observed by adding scavengers. This fact was due to higher affinity to react with free radicals. To confirm degradation of CV, FTIR spectra and nitrate ion level were taken. Also, to recognize toxicity the treated wastewater was tested against coliform bacteria. Growths of Escherichia coli in EMB medium were observed. As a result, it confirms that the treated effluent can be discharged to environment.

Adsorption Behavior of Acid-Treated Brazilian Palygorskite for Cationic and Anionic Dyes Removal from the Water

“…After the CV dye's adsorption on the Pal and Pal-2M samples (Figure 12a), new bands were detected at 1588 cm −1 and 1366 cm −1 . These bands were due to the stretching vibrations C=C and C-N that are characteristic of the CV dye [106,107]. Such bands confirm the removal of the CV dye molecules from the aqueous solution after adsorption by chemisorption [108].…”

Adsorption Behavior of Crystal Violet and Congo Red Dyes on Heat-Treated Brazilian Palygorskite: Kinetic, Isothermal and Thermodynamic Studies

“…After CV dye adsorption ( Figure 11 ), a new band was detected at 1588 cm −1 . This band refers to the C=C elongation vibration of the benzene ring, which is characteristic of the CV dye [ 127 , 128 ]. This band suggests that removing CV dye molecules from the aqueous solution occurred by chemisorption [ 129 ].…”

Recent Achievements in Dyes Removal Focused on Advanced Oxidation Processes Integrated with Biological Methods

“…Synthesizing of new, efficient, nature-based, or waste-originating adsorbents, kinetic, equilibrium and thermodynamic studies on biosorption [42][43][44][45][46] Coagulation/flocculation Synthesizing of new, efficient, nature-based, or waste-originating coagulants and acceleration of sedimentation by magnetic field [47][48][49][50][51][52] Electro-coagulation Ultra-sound assistance, nanofilms on cathodes and solar power usage [53][54][55][56][57][58] Electrochemical oxidation Air-diffusion cathodes, new materials and coatings of electrodes, membrane anode and electro-peroxone process [59][60][61][62][63][64] Membrane filtration Novel membrane materials, with addition of graphene, stabilization of membranes by biomacromolecules [65][66][67][68][69][70] Ozonation Catalyst addition, enhancement by ultrasound and hydrodynamic cavitation [71][72][73][74][75] O 3 /UV Photocatalytic membranes [76] O 3 /H 2 O 2 Proposal of the degradation mechanism, enhancement by electrolysis, heterogenous catalyst addition [77][78][79] UV/H 2 O 2…”

“…Ozone, when combined with H 2 O 2 , improved the efficacy of colour removal from 72 to 90% for a 100 ppm dye solution [ 178 ]. The degradation of crystal violet (CV) was investigated by different oxidation processes [ 79 ]. The results show that all processes were capable of decolorization.…”