Decolorization Of Crystal Violet Research Articles

Decolorization of crystal violet by mixed culture under the influence of Bioelectrochemical stimulation

A significant variation in the relative representation of copies of bacterial genes of dye-decolorizing DyP peroxidases typical for the genus Shewanella and a number of other microorganisms was found in the bottom sediments of freshwater reservoirs. It was found that the specific rate of decolorization of crystal violet in a laboratory bioelectrochemical system by a mixed culture of bottom sediments, which showed the highest representation of DyP genes, depended on the method of electrical stimulation of the external circuit and the concentration of the dye. After an increase in the concentration of more than 20 microns, the maximum speed was achieved in the presence of an ionistor polarly connected to the external electrical circuit of the bioelectrochemical system and amounted to 3.23 ± 0.11 μM/h, while with the opposite polarity connection, a minimum value of 2.07 ± 0.08 μM/h was observed. In the case of an open circuit and a resistor, similar indicators occurred – 2.88 ± 0.09 and 2.67 ± 0.12 μM/h, respectively. When analyzing the decolorization products, a consistent decrease in the maxima of the absorption bands of the dye was noted, indicating its more complete degradation by mixed culture. The results may be of interest for the development of methods to improve the efficiency of bioelectrochemical methods of environmental biotechnology, by electrostimulation of the external circuit.

Isolation and Characterization of Staphylococcus saprophyticus from Textile Industry Soil for Decolorization of Crystal Violet Dye

Textile dyes are an important class of synthetic organic compounds and are, therefore, common industrial pollutants. They are produced in large scale and may enter the environment during production or later on during fiber dying. Thus, there is a need for developing treatment methods that were more effective in eliminating dyes from textile waste soil as its source. Staphylococcus saprophyticus was isolated from soil of a textile plant and selected as the most active dye degrader of 11 isolates. The important parameters including temperature, pH, carbon and nitrogen source on crystal violet decolorization were investigated. Under the optimum conditions, dye decolorization (92.35%) was successfully achieved within 120 h. at 30°C, pH 8 with sucrose and beef extract as the energy source.

Decolorization of Crystal Violet by a Mixed Culture under the Influence of Bioelectrochemical Stimulation

Decolorization of Crystal Violet by a Mixed Culture under the Influence of Bioelectrochemical Stimulation

Decolorization and degradation of crystal violet dye by electron beam radiation: Performance, degradation pathways, and synergetic effect with peroxymonosulfate

Ionizing radiation (mainly including gamma ray and electron beam) technology provides a more efficient and ecological option for dye-containing wastewater treatment, which is supported by its successful achievements in industrial-scale applications. However, the degradation pathway of triphenylmethane dyes by radiation technology is still unclear. In this study, crystal violet (CV) was selected as representative cationic triphenylmethane dye, the decolorization and degradation performance by electron beam radiation technology was systematically evaluated. The results showed that CV can be efficiently decolorized and mineralized by radiation, and its degradation kinetics followed the first-order kinetic model. The effect of inorganic anions and chelating agents commonly existed in dye-containing wastewater on CV decolorization and total organic carbon (TOC) removal was explored. Quenching experiments, density functional theory (DFT) calculation and high performance liquid chromatography mass spectrometry (HPLC-MS) analysis were employed to reveal CV decolorization and degradation mechanism and pathway, which mainly included N-demethylation, triphenylmethane chromophore cleavage, ring-opening of aromatic products and further oxidation to carboxylic acid, and mineralization to CO2 and H2O. Additionally, electron beam radiation/PMS process was explored to decrease the absorbed dose required for decolorization and degradation, and the synergetic effect of radiation with PMS was elucidated. More importantly, the findings of this study would provide the support for treating actual dyeing wastewater by electron beam radiation technology.

Optical spectroscopic analysis, supercapacitance, photocatalysis of BaTixFe12-(4/3)xO19 hexagonal nanoparticles

Obviously, BaTixFe12-(4/3)xO19 Hexagonal nanocrystals are excellent candidates as photocatalysts in water purification, as well as using them as electrode materials for supercapacitors and energy storage applications. M-Type Hexagonal nanoparticles (BaTixFe12-(4/3)xO19, 0 ≤ x ≤ 1) with the magneto-plumbite structure were formerly synthesized by co-precipitation procedure and investigated by several techniques such as XRD, FT-IR, Raman, Photoluminescence and UV-VL. XRD and FT-IR confirmed the structure, and Raman spectra showed 12 characterizing summits. Photoluminescence emission spectra indicated two summits at 448 and 501 nm. Optical UV-VL spectroscopic analysis parameters showed dependence on λ and x. Obviously, BaTi0.75Fe11O19 nanocrystals as a sort of M-Type Hexagonal Ferrites showed excellent Photocatalytic activity on the Degradation of Organic Dyes like; Crystal Violet, Methyl Orange, … etc. Furthermore; these nanocrystals possess excellent electrochemical performance; which in turn introduces these materials for Supercapacitors Applications. Thus, the Photo-catalytic activity of BaTi0.75Fe11O19 nanocrystals for the decolorization of Crystal Violet (CV) dye (1 × 10-5 M) illuminated excellent photocatalytic efficiency reaching ≈ 85%. On the other hand; BaTi0.75Fe11O19 nanoparticles exhibited a specific capacitance of 1858 mF/g at 50 mV/s. The current study introduces promising applications of BaTi0.75Fe11O19 nanoparticles as electrode materials for super capacitance and energy storage.

Bacterial cellulose: An eco-friendly low cost biomaterial for dye removal

Bacteria cellulose (BC) is a non-toxic, environmentally friendly, and biodegradable material. Additionally, it is a cheap, easily accessible, and renewable resource. It possesses exceptional properties and is widely used in a variety of industries, including textiles, paper manufacturing, food, pharmaceutical, and waste treatment. The purpose of this study was to assess the capacity for bioadsorption of pure BC in its wet and dry forms . After 210 minutes of incubation at 37°C, 120 rpm, wet and dry BC exhibit the maximum decolorization of Crystal violet (100 mg/L) at 62.72% and 71.32%, and Congo red (100 mg/L) at 44.28% and 35.23%, respectively. Additionally, the characterization and kinetic model of BC were investigated in parallel. In summary, the findings of this work imply that the application of BC in bioadsorption of dyes may be a potential and successful method for solving the concerns of environmental pollution in a way that is low-cost, simple, and environmentally friendly.

Decolorization of Dyes in the Bioelectrochemical System Depending on the Immobilization of <i>Shewanella oneidensis</i> MR-1 Cells on the Anode Surface and Electrical Stimulation of the External Circuit

The effect of the polarity of the electrical stimulation of the external circuit of the bioelectrochemical systems, as well as the immobilization of Shewanella oneidensis MR-1 cells containing the DyP peroxidase gene on the rate of discoloration of dyes of different types was found. For the crystal violet triphenylmethane dye, the maximum decolorization rate by suspended S. oneidensis MR-1 cells 2.05 ± 0.07 μM/h was noted in the case of connecting a 1.2 V direct polarity DC voltage source. One of the minimum rates was observed in the case of reverse polarity of the connection. In the case of cells immobilized on the anode, the rate was higher, reaching 2.91 ± 0.09 μM/h and did not decrease with increasing substrate concentration. The lowest values were also noted for the reverse connection of the voltage source. In case of the azo dye congo red, the maximum rate was found for a source with direct connection and an open circuit (0.26 ± 0.01 and 0.29 ± ± 0.02 μM/h, respectively), the minimum value is 0.11 ± 0.02 μM/h for reverse connection. For the crystal violet decolorization products, a significant decrease in the intensity of the main absorption peak at 590 nm band was found, with no notable hypsochromic shift. The qualitative changes in the decolorization products composition are indicated by the appearance, in case of a direct polarity of the ionistor connection, of a new absorption maximum in the region of 360 nm. The results may be of interest for the development of new methods of bioelectrochemical cleaning.

Preparation of S-Scheme g-C3N4/ZnO Heterojunction Composite for Highly Efficient Photocatalytic Destruction of Refractory Organic Pollutant

In this study, graphitic carbon nitride (g-C3N4)-based ZnO heterostructure was synthesized using a facile calcination method with urea and zinc nitrate hexahydrate as the initiators. According to the scanning electron microscopic (SEM) images, spherical ZnO particles can be seen along the g-C3N4 nanosheets. Additionally, the X-ray diffraction (XRD) analysis reveals the successful synthesis of the g-C3N4/ZnO. The photocatalytic activity of the synthesized catalyst was tested for the decolorization of crystal violet (CV) as an organic refractory contaminant. The impacts of ZnO molar ratio, catalyst amount, CV concentration, and H2O2 concentration on CV degradation efficiency were investigated. The obtained outcomes conveyed that the ZnO molar ratio in the g-C3N4 played a prominent role in the degradation efficiency, in which the degradation efficiency reached 95.9% in the presence of 0.05 mmol of ZnO and 0.10 g/L of the catalyst in 10 mg/L of CV through 120 min under UV irradiation. Bare g-C3N4 was also tested for dye decolorization, and a 76.4% dye removal efficiency was obtained. The g-C3N4/ZnO was also tested for adsorption, and a 32.3% adsorption efficiency was obtained. Photocatalysis, in comparison to adsorption, had a dominant role in the decolorization of CV. Lastly, the results depicted no significant decrement in the CV degradation efficiency in the presence of the g-C3N4/ZnO photocatalyst after five consecutive runs.

Crystal violet decolorization assay: a simplified colorimetric test for the rapid detection of multidrug-resistant Mycobacterium tuberculosis isolates

The increased prevalence of multi-drug resistant M. tuberculosis is quite possibly the direst and most difficult task for the early diagnosis and treatment. A rapid, reliable, and inexpensive diagnostic method is the need of the hour. The current study on crystal violet decolorization assay explores the possibility to develop a rapid and simple detection method to detect multi-drug-resistant tuberculosis isolates by comparing the results with the traditional liquid culture drug susceptibility testing method based on their sensitivity, specificity, positive predictive value, and negative predictive value. 70 isolates were used for the study and were detected as multi-drug resistant, mono drug-resistant, and sensitive by using crystal violet decolourization assay and further compared with the results of DST and using H37Rv as the standard control strain. The sensitivity, specificity, positive predictive value, and negative predictive value of crystal violet decolorization assay (Rifampicin: 100%, 94.60%, 100% and 82.40%; isoniazid: 100%, 94.10%, 100%, 86.40%) are calculated and the percentage were compared with the conventional liquid culture drug susceptibility testing for M. tuberculosis using rifampicin and isoniazid. Crystal violet decolourization assay is rapid, reproducible, and doesn't require any highly experienced personal or sophisticated laboratory instruments for interpretation. This assay is found to be nearly as reliable as conventional liquid culture drug susceptibility testing and may thus be of great help in phenotypic confirmation of multi-drug resistant tuberculosis by providing results more rapidly.

Influence of NaOH concentration on the decolorization of crystal violet dyed cotton fabric

Synthetic dye removal is a topic of increasing interest as textile recycling has become more popular in industries. While methods involving dye removal from wastewater effluent have been widely studied and reported on, research on decolorization of fabric itself remains quite unknown. In regard to the lack of research, this study presents cotton fabric samples dyed with crystal violet (CV) that were treated with varying concentrations of sodium hydroxide (NaOH). Fabric decolorization was studied using several characterization methods. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy data showed that the cellulose structure remained unchanged after CV and NaOH treatment. Characteristic CV peaks in the FTIR and Raman spectra were apparent only in the control sample, while the spectra of NaOH-treated samples were very similar to that of the cotton fabric. X-ray diffractometry (XRD) data also confirmed that the crystallite size of cellulose was not affected by CV and NaOH treatment. A visible violet hue remained in all NaOH-treated samples, though CV intensity was inversely proportional to NaOH concentration. The L*a*b* values were utilized to complement characterization results. As the concentration of NaOH was increased, the CIELAB parameters aligned more with those of the plain untreated fabric.

Bioremediation Potential of Chlorella vulgaris and Nostoc paludosum on azo Dyes with Analysis of Metabolite Changes

Microalgae have been used widely in bioremediation processes to degrade or adsorb toxic dyes. Here, we evaluated the decolorization efficiency of Chlorella vulgaris and Nostoc paludosum against two toxic dyes, crystal violet (CV) and malachite green (MG). Furthermore, the effect of CV and MG dyes on the metabolic profiling of the studied algae has been investigated. The data showed that C. vulgaris was most efficient in decolorization of CV and MG: the highest percentage of decolorization was 93.55% in case of MG, while CV decolorization percentage was 62.98%. N. paludosum decolorized MG dye by 77.6%, and the decolorization percentage of CV was 35.1%. Metabolic profiling of C. vulgaris and N. paludosum were performed using NMR spectroscopy. Based on 1D and 2D NMR data, 43 compounds were identified in the polar extract of C. vulgaris, while 34 polar metabolites were successfully determined in N. paludosum. The identified compounds included carbohydrates, amino acids, organic acids, dipeptides, steroids and phenols. Statistical analysis was carried out to recognize the pattern of metabolite variation between control and dye treated samples. Principal component analysis (PCA) and hierarchical cluster analysis showed that samples treated with MG are clearly separated from the control in both types of algae. Based on heat map data, the level of carbohydrates and amino acids concentrations are strongly affected by bioremediation of MG dye compared with CV dye. In conclusion, the present study proved that CV and MG dyes are considered as stress factors and the studied algae species exert their bioremediation activity without the dyes being absorbed into the cells.

Controlled hydrothermal synthesis of BiOxCly/BiOmBrn/g-C3N4 composites exhibiting visible-light photocatalytic activity

The first systematic synthesis of bismuth oxychloride/bismuth oxybromide/graphitic carbon nitride (BiOxCly/BiOmBrn/g-C3N4) nano-composites used a controlled hydrothermal method. The structure, morphology and characteristic of BiOxCly/BiOmBrn/g-C3N4 photocatalyst were measured by XRD, UV–vis-DRS, FT-IR, FE-TEM, FE-SEM-EDS, PL, BET, HR-XPS and EPR. Under visible light irradiation, the photodegradation activity was evaluated for the decolorization of crystal violet (CV) and 2-hydroxybenzoic acid (2-HBA) in aqueous solution. The catalytic performance showed that, when using sample BB2C1-4-250-30 wt% g-C3N4 composite as a photocatalyst, the best reaction-rate-constant (k) was 0.071 h−1. It was 1.5 times higher than the k value of BB2C1-4-250 as a photocatalyst. From the scavenging effect of various scavengers, the results of EPR showed that reactive OH was the main scavenger, while O2−, h+ and 1O2 were the second scavenger in CV degradation. In this study, a possible photodegradation mechanism was proposed and discussed. In this work, our method of BiOxCly/BiOmBrn/g-C3N4 preparation could be used for future mass production and the BiOxCly/BiOmBrn/g-C3N4 composite materials could be applied to the environmental pollution control in future.

Visible light photocatalysis promoted by homogenously doped (non-metals) anatase from a chelated titanium precursor

The anion-modified titania finds extensive application in many solar energy-mediated processes. The current study addresses the generation of anatase homogeneously co-doped with carbon and nitrogen with the help of the polyaminocarboxylate backbone of EDTA complexed with titanium. Various physicochemical techniques were used to characterize the sample from the hydrothermally hydrolyzed product of Ti-EDTA. The anatase polymorph formed from this reaction was yellow in color and suggested a defective one. The crystallites had an average size of 12 nm. The tetragonal lattice dimensions showed deviation from the pure anatase, confirming the presence of oxygen vacancies. The electron microscopy experiments demonstrated the homogeneity and its tetragonal symmetry. The XPS analysis confirmed 9.5 and 1.5 % of carbon and nitrogen-doped in the anatase as Ti–O–C/N species. Raman spectrum indicated lattice disorder caused by the co-doping carbon and nitrogen. The oxygen vacancies showed paramagnetic signal in the EPR spectrum both at room temperature and at 77 K. Emission in the blue region in the photoluminescence spectrum confirmed the existence of oxygen vacancies. The sample showed absorption in the entire UV region extending up to the visible region and had an optical bandgap of 2.8 eV. The sample exhibited excellent catalytic activity in the visible light, promoted decolorization of crystal violet, rhodamine 6G dye solutions following pseudo-first-order kinetics. The sample also catalyzed 85 % of bisphenol (BPA) degradation under visible radiation, from which salicylaldehyde was identified as the major product by the GC-MS analysis. The catalyst retained its ability up to three times its reuse without undergoing any structural change. OH● radicals have been identified as the reactive oxidation species (ROS) involved in these experiments with scavenger experiments.

Removal of crystal violet by Cu-chitosan nano-biocomposite particles using Box–Behnken design

Copper nanoparticles (CuNPs) impregnated biocomposites (Cu/chit-NBC) were prepared and characterized by the state-of-the-art analytical techniques. The CuNPs were in the average size ranges of 45.6–63.7 nm and 86.4 nm as confirmed by scanning electron microscopy and dynamic light scattering, respectively. To decolorize the crystal violet from the aqueous medium, fabricated Cu/chit-NBC was applied as an adsorbent. Box–Behnken design using three independent variables was adopted to optimize the Crystal Violet (CV) decolorization process. Under the optimum conditions of temperature 42.7 °C, pH 9.5, and 149.9 mg L−1 dose of adsorbent, 99.7 ± 0.2% decolorization was observed. Cu/chit-NBC also showed a very high dye removal capacity in simulated industrial textile effluents of around 99.7 ± 0.2%. The CV decolorization was consistent with pseudo-second-order kinetics and best fitted with the Freundlich adsorption isotherm. The nature and the potential processes involved in interactions between the CV and the nano-bioadsorbents during discoloration have been discussed in this paper.

Photocatalytic activity of (Er2O3)x(Yb2O3)y(Bi2O3)1-x-y ternary compounds used as heterogeneous semiconductor

In this study, bismuth oxide ternary compounds, (Er2O3)x(Yb2O3)y(Bi2O3)1-x-y, were synthesized at 800 °C annealing temperature with different stoichiometric ratios by the solid-state reaction method. Synthesized ternary compounds were characterized by scanning electron microscopy (SEM), X-ray Diffraction (XRD), and zeta potential. The synergic effect of (Er2O3)/(Yb2O3)/(Bi2O3) ternary compounds was investigated for photocatalytic oxidation of an azo dye Crystal Violet (CV), also known as C.I. Basic Violet 3, in aqueous solutions. The influence of stoichiometric ratios of Er3+ and Yb3+ doping on Bi3+, powder loading, and dye concentration were systematically investigated. A complete CV decolorization (5 mg/L initial dye concentration) was obtained by 8Er15YbSB mol/mol% at 4 g/L powder loading for 30 min. (Er2O3)/(Yb2O3)/(Bi2O3) ternary compounds reusability was also tested during 5 cycles and ternary compounds remained half of its activity even when in fourth reuse.

Cotton Textile/Iron Oxide Nanozyme Composites with Peroxidase-like Activity: Preparation, Characterization, and Application

At present, both native and immobilized nanoparticles are of great importance in many areas of science and technology. In this paper, we have studied magnetic iron oxide nanoparticles and their aggregates bound on woven cotton textiles employing two simple modification procedures. One modification was based on the treatment of textiles with perchloric-acid-stabilized magnetic fluid diluted with methanol followed by drying. The second procedure was based on the microwave-assisted conversion of ferrous sulfate at high pH followed by drying. The structure and functional properties of these modified textiles were analyzed in detail. Scanning electron microscopy of native and modified textiles clearly showed the presence of iron oxide nanoparticles on the surface of the modified cotton fibers. All of the modified textile materials exhibited light to dark brown color depending on the amount of the bound iron oxide particles. Magnetic measurements showed that the saturation magnetization values reflect the amount of magnetic nanoparticles present in the modified textiles. Small-angle X-ray and neutron scattering measurements were conducted for the detailed structural characterization at the nanoscale of both the native and magnetically modified textiles, and different structural organization of nanoparticles in the two kinds of textile samples were concluded. The textile-bound iron oxide particles exhibited peroxidase-like activity when the N,N-diethyl-p-phenylenediamine sulfate salt was used as a substrate; this nanozyme activity enabled rapid decolorization of crystal violet in the presence of hydrogen peroxide. The deposition of a sufficient amount of iron oxide particles on textiles enabled their simple magnetic separation from large volumes of solutions; if necessary, the magnetic response of the modified textiles can be simply increased by incorporation of a piece of magnetic iron wire. The simplicity of the immobilized nanozyme preparation and the low cost of all the precursors enable its widespread application, such as decolorization and degradation of selected organic dyes and other important pollutants. Other types of textile-bound nanozymes can be prepared and used as low-cost catalysts for a variety of applications.

Sonocatalytic performance of eggshells loaded with transition metal ions for decolorization of crystal violet dye

In this study, divalent transition metal ions namely Fe(II), Co(II), Ni(II) and Cu(II) were loaded on the eggshells by a simple impregnation method and characterized by UV–vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), Brunauer–Emmett–Teller (BET) surface area analyzer, X-ray photoelectron spectrometer (XPS), and X-ray diffraction (XRD) techniques. The metal ions loaded eggshells were investigated for the sonocatalytic degradation of a triarylmethane dye, crystal violet (CV) under ultrasonic irradiation. The experimental conditions like sonocatalyst dosage, dye concentration and ultrasound irradiation time were optimized based on decolorization of CV. The results evidenced an excellent sonodegradation performance of Fe(II) loaded eggshell towards CV, within 30 min, when compared to other metal ions loaded eggshell. The sonodegradation mechanism has been proposed and the recycle capacity upto 5 cycles was investigated with only ∼8 % decrease in degradation efficiency.

A novel multi array dielectric barrier discharge plasma gas diffuser for wastewater treatment: The role of reactive species

Employment of efficient and economical methods for recovery of water has come into sharp focus regarding the growing demand for fresh water which has led to water crisis in a recent past. In this respect, cold atmospheric plasma technology has recently attracted scholars’ attention due to its various chemical and physical effects which can contribute to the removal of contaminations in wastewater. Although the energy efficiency and the rate of pollution elimination from water have been studied extensively, only few studies have been conducted on reactive species that play a major role in eliminating pollution. We studied the chemical reactive species involved in the decomposition of crystal violet (CV), a model organic compound, by a novel multi array dielectric barrier discharge (MADBD) plasma gas diffuser. The plasma generated gas mixture immediately contacts with the water in the form of gas bubbles to insure a good mass transfer between short and long live reactive species and water. Effects of operating parameters including electrode length, input power, flow rate, and solution volume over CV decolorization and energy efficiency were investigated. Experimental results showed that for the best operating conditions decolororization, energy efficiency, and CV decolorization rate constant were 95%, 7.8 g/kWh, and 2.83 min−1, respectively. An investigation of positive control experiments and the effect of scavengers of relevant reactive species reveal that the most key reactive species leading to the CV decolorization in MADBD plasma was ozone (O3) while short live species and reactive nitrogen species had small effect on CV degradation.

Hybrid System of Flocculation-Photocatalysis for the Decolorization of Crystal Violet, Reactive Red X-3B, and Acid Orange II Dye.

A hybrid system of flocculation–photocatalysis (HSFP) was applied to evaluate the color removal from simulative dye wastewater. The decolorization performance of HSFP was investigated considering four key factors: flocculant dosage, pH, turbidity, and ionic strength. Compared with flocculation alone, HSFP showed better decolorization effectiveness for simulative Crystal Violet–Reactive Red X-3B dye wastewater (CV-RR) and simulative Crystal Violet–Acid Orange II dye wastewater (CV-AO). The dosage of flocculant was determined by the molecular structure of target dyes. A higher dosage was required for the color removal of dyes with a lower molecular weight and less sulfonic acid groups. The dominant decolorization mechanism was different with different initial pH values of simulative dye wastewater, which influenced the decolorization efficiency of flocculation and photocatalysis. For dyes with a lower molecular weight and less sulfonic acid groups, better decolorization performance was achieved under neutral conditions, mainly depending on strong charge neutralization and adsorption bridging capacity. For dyes with a higher molecular weight and more sulfonic acid groups, decolorization efficiency was improved with an increase in pH, due to stronger deprotonation. An increase of turbidity reduced the dye removal efficiency of flocculation alone and HSFP. The presence of NaCl, CuCl2, and CrCl3 led to a different decrease in the flocculation efficiency and photodegradation efficiency.

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

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.