Dye Decolourization Research Articles

Investigating the effect of dimethyl dioxirane as oxidizing agent in the degradation of rhodamine B

The degradation of Rhodamime B was carried out at ambient temperature in the presence of dimethyl dioxirane (DMDO). The influence of dye concentration, pH and dimethyl dioxirane dosages was investigated. UV-Visible spectroscopy was used to determine before and after degradation of Rhodamine B dye, the absorption peak decreases gradually after 30min of reaction time. FTIR analysis was carried to determine the functional group. The final degraded product and intermediates were determined by GC-MS analysis. These variables have a significant impact on dye degradation. The proportion of decolouration reduced as the initial dye concentration was increased, as expected. Similarly, increasing the DMDO concentration improved dye decolouration until a certain point, after which it began to decline. 10 mg of rhodamine B dye, 500μl of dimethyl dioxirane at pH 7 were found to be the best operating parameters for the procedure. The dye was decolorized to a maximum of 93% under these conditions.

Electrocoagulation using scrap materials for removal of dye with different connection modes and electrode combinations

This study analyses the efficiency of electrocoagulation (EC) process by utilizing discarded metal scrap of Iron (Fe) and Aluminium (Al) as electrodes for decolourization of azo dye, Acid Yellow 36 (AY36). Different modes of connection such as mono polar parallel (M-P), mono polar series (M-S) and bi polar series (B-S) were investigated for the performance of percent colour removal and Electrical Energy Consumption (ENC). Within these connections, different electrode arrangements, such as Iron-Aluminium-Iron-Aluminium, Aluminium-Iron-Aluminium-Iron, Iron-Iron-Iron-Iron and Aluminium-Aluminium-Aluminium-Aluminium were analyzed for the dye removal efficiency. The parameters varied during the experimental runs were current density (CD) and pH. M–S showed maximum colour removal of 99.2% with system of mixed electrode Fe–Al–Fe–Al at CD 10 A/m2 and ENC 0.322 Kwh/Kg dye removed. Whereas M-P showed 98.4% colour removal with hybrid system Fe–Al–Fe–Al at CD of 20 A/m2 with ENC 0.209 Kwh/Kg dye removed. B-S showed 99.1% colour removal with mixed electrode system Al-Fe-Al-Fe at CD of 20 A/m2 and ENC 0.86 Kwh/Kg dye removed. Overall, M-S mode gave the maximum colour removal, while M-P gave minimum ENC. The study proved useful in terms of lowering the cost of electrocoagulation by using scrap metal as electrodes and choosing the right electrode combination and connection mechanism.

Photocatalytic Degradation of Magenta Effluent Using Magnetite Doped TiO2 in Solar Parabolic Trough Concentrator

Due to population growth and industrial development consumption of non-renewable energy sources, and consequently pollution, has increased. In order to reduce energy utilisation and preserve the environment, developed and developing countries are increasingly trying to find solutions based on renewable energy sources. Cost-effective wastewater treatment methods using solar energy would significantly ensure effective water source utilisation, thereby contributing towards sustainable development goals. In this paper, special emphasis is given to the use of solar energy as the driving force of the process, as well as the use of highly active magnetic TiO2-based catalysts. Therefore, in this study, we investigated the possibility of photocatalytic degradation of aqueous magenta graphic dye using titanium dioxide as a catalyst and DSD model in order to achieve the best process optimisation. TiO2 was successfully coated with magnetic nanoparticles by one step process and characterized using different techniques (BET, SEM/EDS, FTIR, XRD). Based on DSD statistical method optimal reaction conditions were pH = 6.5; dye concentration 100 mg/L; TiO2–Fe3O4 0.6 g/L, at which the highest degree of magenta dye decolourisation was achieved (85%). Application of solar energy coupled with magnetic TiO2 catalyst which could be recovered and reused makes this approach a promising alternative in green wastewater treatment.

Biodecolourisation of Bismarck Brown dye using Orange peel

Dyes discharged from dyeing units and textile industries pollute the environment, particularly aquatic systems and cause considerable damage to organisms. Removal of colour is a prerequisite for discharge of treated textile effluents into the environment. Though several physical and chemical methods are available for decolourisation, biosorption is considered as cost effective and ecofriendly technique. Hence, in the present study, we explored possibilities of using orange peel for decolourisation of Bismarck brown dye, one of most common dyes used in the textile industry. Orange peel in different quantities (0.2, 0.4, 0.6 and 0.8 g/100 mL) was tested with 0, 100, 200, 300 and 400 ppm concentrations of Bismarck Brown dye for ten days. The decolourisation activity proportionally increased with the increase in the treatment period. The dye concentration of 100 ppm was tested with 0.4 g orange peel in different pH ranges of 2, 4, 6, 8 and 10 and the absorption was high in acidic pH. The increase in contact time also resulted in increased dye removal. Over all, the adsorption of dye onto orange peels was influenced by initial dye concentration, pH, amount of adsorbent and contact time. Four grams of orange peel showed highest decolourisation after 200 min, and it was proportional to the contact time. The dye removal was the maximum at pH 2. Both Langmuir (R2 = 0.922) and Freundlich (R2 = 0.999) adsorption isotherms were calculated.

Altering the Photoluminescence Emission Quenching and Energy Transfer for the Photocatalytic Behaviour of ZnO Nanostructures

Synthesis of nanoparticles (NPs) is gaining attention as a cost-effective and environmentally acceptable alternative to remove the pollutant by facile photocatalysis process. Role of hydrothermal treatment on Zinc-oxide (ZnO) nanostructures were investigated using non-ionic surfactant diethanolamine (DEA). Further, in order to investigate the effect of DEA on morphological variation different concentration of DEA was used. The samples were thoroughly characterized by XRD, Rietveld analysis, FESEM and TEM to get insight idea about the ZnO structural and morphological properties. Moreover, XPS spectra reveal the variation of surface oxygen defects as hydrothermal treatment induced more defects to ZnO material. BET measurement reveals the alteration of surface area and pore size of ZnO sample. The surface defect-states (mostly oxygen vacancies) of the catalyst nanoparticles can influence the photocatalytic degradation of MB dye activated by ZnO nanoflowers via a non-radiative energy transfer pathway. A steady-state photoluminescence analysis validated the photoinduced electron transport from ZnO to MB dye. Steady state photoluminesence emission spectra established one to one correlation between the defects and colour emission from ZnO. Spectral overlap between donor (ZnO) to acceptor (MB dye) also enhanced greatly after hydrothermal treatment ascribing more Förster resonance energy transfer (FRET) which accelerates photocatalytic degradation efficiency of methylene blue (MB) dye under UV light irradiation. The defect-engineered ZnO nanoparticles synthesized through facile hydrothermal treatment led to an efficient decolourization of MB dye which was strengthened by FRET based on a correlation of photocatalytic degradation and defect mediated colour emission.

EVALUATION OF THE EFFICIENCY OF EGGSHELL ASH AS PHOTOCATALYST FOR DECOLOURISATION OF AZO DYE USING SOLAR UTRA-VIOLET RADIATION

Water pollution is one of the environmental challenges to be surmounted to avoid global public health hazard. Due to the complex chemical structure, azo dyes in industrial effluent have a long shelf life and are toxic to aquatic creatures even at low quantities. In this study, the decolourisation of azo dye, methylene blue (MB) using locally sourced photocatalyst, eggshell ash (ESA) under solar ultra-violet (UV) radiation was investigated. In order to test the photo-activities of ESA, a similar study was performed without sunlight. ESA was characterised using Fourier transform infrared (FTIR) spectroscopy. Maximum decolourisation efficiencies (96% with sunlight and 77% without sunlight) were recorded at contact time of 120 minutes and 1.5 g/dm3 of catalyst. The data obtained were fitted into kinetics models and adsorption isotherms. According to the findings, pseudo-second order kinetics model best described the process with rate constant of 0.1529 g/mg.min and regression value, R2 of 0.9934. Intra-particle diffusion model showed that the uptake of MB was more of film diffusion than the intra-particle diffusion. The adsorption isotherm fitted better into Langmuir isotherm with adsorption capacity of 0.0213 dm3/mg and R2 of 0.9957, while the Temkin isotherm indicates that the process was a physical adsorption as the heat of sorption value (0.0015 Kcal./mol.) was less than 1.0 kcal/mol. Generally, the study revealed that ESA was a suitable photocatalyst for the decolourisation of azo dyes under solar UV rays.

A comprehensive review on sustainable greener nanoparticles for efficient dye degradation.

The effluents released from textile industries mainly consist of dyes, metals and other pollutants. Dyes often are discharged in wastewater streams causing adverse effect on the environment. To eliminate these harmful dyes, various techniques are emerging out of which nanotechnology is the most reliable and safer. Nanotechnology offers convincing applications in case of environmental and economic concerns. The bio-synthesis of nanoparticles has several advantages over conventional methods and approach towards environment concern as well. Biological method of nanoparticles synthesis is concluded to be the most promising and efficient in action. Bio-synthesised nanoparticles could be used for treatment and decolourisation of dyes in an efficient manner. This review comprises the study of number of bio-synthesised nanoparticles utilised for degradation of various dyes present as pollutants in wastewater. Bio-synthesised nanoparticles such as gold, silver, iron, cobalt, zinc, titanium and molybdenum used for degradation of various dyes have been discussed in this review.

Intensification of Recombinant Laccase Production from Sago Bioethanol Liquid Waste and Evaluation of The Enzyme for Synthetic Dye Decolourisation

Purpose: Laccases are polyphenol oxidases that have diverse industrial applications. High industrial demand of laccases has necessitated the development of cost-effective production of recombinant laccases. One of the ways is by utilizing waste stream that has valuable composition for supporting microbial growth and metabolite expression. This work aims to intensify the production of recombinant laccases in Pichia pastoris GS115 using sago bioethanol liquid waste (SBLW) as a feedstock. Method: Production of laccases from SBLW was intensified by the addition of glycerol ranging from 0.5% - 2.5% (w/v). The fermentation performance was assessed based on the biomass concentration and laccase activity. The resulting laccases produced were further evaluated in terms of the capability of the enzyme to decolourise Remazol Brilliant Blue R dye. Results: The results showed that supplementation of SBLW with 2% (w/v) glycerol yielded improvements of 1.9-fold and 2.1-fold of biomass concentration and laccase activity, respectively in comparison to that achieved by fermentations using the standard Buffered Methanol-Complex Medium. Furthermore, the laccases produced using the optimal SBLW medium yielded a decolourisation percentage of 68.6% under non-optimised conditions and in the absence of mediators. The value represents 91% of the decolourising capability of laccases produced using the standard BMMH. Conclusion: In general, this works represents a further step towards low-cost production of recombinant laccases using renewable feedstocks.

Towards passive bioremediation of dye-bearing effluents using hydrous ferric oxide wastes: Mechanisms, products and microbiology

A novel, circular economy-inspired approach for the “passive” (non-powered and reagent-free) treatment of dye-bearing effluent is presented. The treatment utilises the biogeochemical interaction of dye-bearing wastewater with hydrous ferric oxide (HFO) bearing sludges. The work presented demonstrates for the first time the reuse of HFO-rich waste sludges from potable water and mine water treatment. The waste was used directly without modification or reagent addition, as media/substrate in simple flow-through reactors for the decolourisation and biodegradation of methyl orange (MO) and mixed dyes textile effluent. Three phases of exploratory proof of concept work were undertaken. Columns containing HFO sludges were challenged with solution of MO, and MO amended with glycerol (Phase I), MO in a synthetic textile effluent recipe (Phase II), and real mixed textile effluent containing a mixture of dyes (Phase III). After an initial lag period extensive decolourisation of dye was observed in all cases at rates comparable with pure strains and engineered bioreactor processes, with evidence of biodegradation beyond simple cleavage of the mono azo chromophore and mineralisation. The microbiology of the initial sludge samples in both cases exhibited a diverse range of iron oxidising and reducing bacteria. However, post experiment the microbiology of sludge evolved from being dominated by Proteobacteria to being dominated by Firmicutes. Distinct changes in the microbial community structure were observed in post-treatment MWTS and WTWS where genera capable of iron and sulphate reduction and/or aromatic amine degradation were identified. Average nitrogen removal rates for the columns ranged from 27.8 to 194 g/m3/day which is higher than engineered sequential anaerobic-aerobic bioreactor. Postulated mechanisms for the fast anaerobic decolourisation, biodegradation, and mineralisation of the dyes (as well nitrogen transformations) include various direct and indirect enzymatic and metabolic reactions, as well as reductive attack by continuously regenerated reductants such as Fe(II), HFO bound Fe(II), FeS, and HS−. The ability of iron reducers to degrade aromatic rings is also considered important in the further biodegradation and complete mineralisation of organic carbon. The study reveals that abundant and ubiquitous HFO-rich waste sludges, can be used without amendment, as a substrate in simple flow-through bioremediation system for the decolourisation and partial biodegradation of dyes in textile effluent.

Thermo-active and alkaliphilic amalgamated laccase immobilized on sodium alginate for synthetic dye decolourization

Purified crude laccase of Enterobacter sp. Kamsi and Bacillus sp. NU2 in the hybrid and combined form was immobilized on sodium alginate beads and applied to decolourize various textile dyes through several decolourization reaction cycles. The enzyme/alginate (E/A) loading efficiency and immobilization yield were evaluated. The SEM-EDX analysis, pH, and temperature effects of both forms of immobilized laccases were examined. The maximum condition for Kamsi and NU2 laccases into Na-alginate beads is 2.5% (w/v), which resulted to >83 and 61.71% immobilization and loading efficiency, respectively. The SEM-EDX analysis showed a rough-spherical surface attributable to significant entrapment of the laccase at the centre of the beads. The hybrid laccase in the free and immobilized form showed >52% and 80% decolourization effects, while the amalgamated laccase showed >63 and 83% decolourizing effect on Malachite Green (MG), Remazol Brilliant Blue R (RBBR), Reactive Blue 4 (RB4), Congo Red (CR), and Methyl Orange (MO), respectively. The immobilized laccase retained >50 and 81% activity of the hybrid and amalgamated laccases, respectively, after six successive treatment cycles. The results showed that the immobilization technique of the Kamsi and NU2 laccase holds the potential for textile dye effluents degradation, but the amalgamation of an enzyme from different species could improve decolourization potentials for various dyestuff treatments.

Adsorptive decolouration of anionic dye from water by goat dropping activated carbon prepared via microwave-assisted H3PO4 activation: process optimization using response surface methodology, isotherm and kinetics modelling

Adsorptive decolouration of anionic dye from water by goat dropping activated carbon prepared via microwave-assisted H3PO4 activation: process optimization using response surface methodology, isotherm and kinetics modelling

High Potential Decolourisation of Textile Dyes from Wastewater by Manganese Peroxidase Production of Newly Immobilised Trametes hirsuta PW17-41 and FTIR Analysis.

Coloured wastewater from the textile industry is a very serious global problem. Among 16 different white-rot fungal isolates, Trametes hirsuta PW17-41 revealed high potential for decolourisation of mixed textile dyes (Navy EC-R, Ruby S3B and Super Black G) from real industrial wastewater samples. The efficiency of dye decolourisation was evaluated using the American Dye Manufacturers’ Institute (ADMI) standard methodology. The suitable support for fungal mycelium immobilisation was nylon sponges. The optimal dye decolourisation (95.39%) was achieved by using palm sugar and ammonium nitrate as carbon and nitrogen sources, respectively. The initial pH was 5 and the agitation speed was 100 rpm at 30 °C. The ADMI values of textile dyes decreased from 2475 to 114 within two days, reducing the treatment time from seven days before optimisation. The major mechanism of dye decolourisation was biodegradation, which was confirmed by UV–visible and FTIR spectra. Manganese peroxidase (MnP) (4942 U L−1) was found to be the main enzyme during the decolourisation process at an initial dye concentration of 21,200 ADMI. The results indicated the strong potential of immobilised fungal cells to remove high concentrations of textile dyes from industrial wastewater and their potential ability to produce high MnP and laccase activities that can be used in further application.

Coco Peat Organic Manure used as Adsorbents for Dyes Removal

Textile effluents constitute both organic and inorganic constituents and heavy metals which are not economical to treat and hence discharged into water bodies causing water pollution. Methods like ozonation, adsorption, membrane separation, bio sorption, biodegradation, electrochemical degradation, and phytoremediation and H2O2/UV radiation techniques were frequently used for the decolourization of azo dye containing water. Among these aforementioned techniques, the adsorption technique has shown good performance owing to several inherent advantages like high performance, easy handling with no generation of the toxic intermediates. Also dye treatment should be affordable and eco-friendly. Biochar is a sustainable material which can be used for dyes treatment.In this paper, biochar produced using coconut shell was investigated for the removal of methylene blue as the colouring agent. Batch studies were carried out for decolourization of methylene blue based artificial waste water. Different concentrations of methylene blue from 50-300mg/l was used. The validation of the tests was done using data to fit into the Langmuir isotherms and Freundlich isotherm. The adsorption isotherm was well fitted for Langmuir compared to Freundlich. The KL and KF values were also found.

Photocatalytic decolourization of Rhodamine-B dye by visible light active ZIF-8/BiFeO3 composite.

In this work, preparation of ZIF-8 supported BiFeO3 photocatalyst by ultrasound cavitation technique was reported. The synthesized materials were characterized using solid UV absorption spectroscopy, Raman Spectroscopy, and SEM. The catalytic function of synthesized photocatalyst under ultraviolet and visible light was examined for the decolourization of Rhodamine-B (Rh-B) dye. To understand the action of the photocatalyst on Rh-B decolorization, the influence of different operating parameters such as wt% of ZIF-8 in composite, catalyst dosage, initial dye concentration, initial solution pH, and source of light was examined. The obtained results show that 40.7 wt% of ZIF-8/BiFeO3 composite exhibited the highest possible photocatalytic behaviour against decolorization of Rh-B dye. The acidic pH of the solution had shown greater effectiveness in removing Rh-B dye. The tests and study demonstrate that the hybrid ZIF-8/BiFeO3 has a stronger photocatalytic activity for decolorization of the Rh-B dye relative to the ZIF-8 MOF and BiFeO3. The synthesized ZIF-8/BiFeO3 demonstrated outstanding photocatalytic behaviour in the presence of ultraviolet and visible light towards the removal of Rh-B dye from the aqueous media.

TiO2/CdS composite photocathode improves the performance and degradation of wastewater in microbial fuel cells.

Optimization of dye decolourization for wastewater and power production are explored in dual-chamber microbial fuel cells (MFCs) with TiO2/CdS photocathodes. The rapid reduction of azo dye methylene blue (MB) and power production were enhanced with TiO2/CdS photocathode under illumination. The analysis of electrochemical impedance spectra indicated that the photocatalysis of TiO2/CdS accelerated the electron transfer process of photoelectrode reduction. Moreover, the UV-visible light spectrophotometer showed that the maximum degradation of the MFCs was 98.25%, which illustrated that MB may be cleaved by photoelectrons generated by light irradiation on the illuminated TiO2/CdS photocathode. Finally, the power production of MFCs in this work promoted reductive decolourization of the dye MB solution.

Decolourization of synthetic dyes by laccase produced from Bacillus sp. NU2

Advanced industrialization has caused an increase in the continuous discharge of hazardous effluents in the environment. This study evaluated the potential of the laccase synthesized by Bacillus sp. NU2 to degrade five synthetic dyes. Sawdust, wheat bran and peels of banana and tangerine were utilized as carbon sources for bacterial growth and laccase production. The produced crude enzyme was purified to homogeneity to determine its molecular weight. The kinetic activity of the purified laccase was determined using 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The toxicity of the laccase-treated dye solution was assessed on Bacillus sp. NU2 growth. The result showed optimum laccase yield from the tangerine peel medium. The purified laccase gave a specific activity of 349.94 U mg−1 and a molecular weight of 55 kDa, respectively. The purified laccase displayed a strong affinity for ABTS substrate with an enzyme activity of 31.21 U mg−1. It was optimum at 60 °C and pH 8, with catalytic efficiency (Kcat /Km ) of 23.93 mmol L−1. The decolourization effects on Congo Red, Methyl Orange, Remazol Brilliant Blue R, Reactive Blue 4 and Malachite Green were 87%, 70%, 65%, 63% and 51%, respectively. The toxicity assay of laccase degraded dyes on Bacillus sp. NU2 showed a growth reduction of 36.75% (Malachite Green), 12.57% (Congo Red), 17.19% (Methyl Orange), 38.41% (Remazol Brilliant Blue R) and 28.14% (Reactive Blue 4). The laccase produced by Bacillus sp. NU2 holds a high catalytic potential for the detoxification of dye effluents in an environmental system.

Microbial and lignocellulosic biomass based dye decolourization

Microbial and lignocellulosic biomass based dye decolourization

PRODUCTION OF BACTERIAL LIGNINOLYTIC ENZYMES AND THEIR POTENTIAL APPLICATION IN DECOLORIZATION OF DYES

Lignin is a complex, three-dimensional aromatic polymer, consisting of dimethoxylated, monomethoxylated and non-methoxylated phenylpropanoid subunits, and is recalcitrant in nature. In this study, the isolation of lignin degrading bacteria was carried out from decaying wood samples. Ligninolytic activity was evaluated by growing bacterial isolates on lignin monomers and by the degradation of indicator dyes. Out of 16, the bacterial isolates L8, L12, L13 and L15 exhibited growth on monomers viz., vanillin, veratryl alcohol, phenol, guaiacol and lignin, with efficient dye decolourization. Further, the production of ligninolytic enzymes (laccase, lignin peroxidase and manganese) was estimated for the 4 selected bacterial isolates. The maximum enzymatic activity response was noted in the case of isolate L15, with the best growth on every lignin monomer.

Potential of Copper-Zinc Oxide nanocomposite for photocatalytic degradation of congo red dye

Congo red (CR) is a toxic azo dye with a complex structure which represents a serious ecotoxicological hazards for aquatic bodies. The present study was aimed to synthesis of metal oxide nanoparticles by applying novel approaches and explore their role in degradation and decolourization of synthetic dye i.e. CR. Zinc oxide (ZnO) and zinc-copper oxides (ZnO/CuO) composite were prepared by the modest chemical co-precipitation process through calcined over 400 °C for 4 h. The acquired materials were characterized by XRD, EDX, SEM, HRTEM, BET, and UV-Visible spectrophotometer. Further, the optimized materials were opted for photodegradation of toxic CR under irradiation of visible light. The experiment demonstrated that ZnO and ZnO/CuO composite can degrade 25% and 95% of CR dye, respectively. ZnO/CuO composite showed better photocatalytic decolorization of CR dye and followed first order kinetics. The result of this study will be helpful in understanding the mechanism of CR degradation through composite materials and help in the development of an efficient technique for degradation and decolourization of CR containing industrial wastewater.

Decolourization and biodegradation of methylene blue dye by a ligninolytic enzyme-producing Bacillus thuringiensis: Degradation products and pathway

In this study, a ligninolytic enzyme-producing strain F5 was isolated and identified as Bacillus thuringiensis, which can efficiently degrade methylene blue (MB) dye. The optimal pH, temperature, rotation speed, NaCl concentration, and inoculum of strain F5 for MB degradation were pH 6.0, 30 °C, 140 rpm, 10 g/L NaCl, 4% inoculum (v/v), and the strain F5 had salt tolerance, the MB decolorization rate reached 95% after 12 h. The degraded products were characterized by UV–vis, FT-IR, and GC-MS. Based on products analysis, four different intermediates were identified, and a new pathway for the degradation of MB was proposed. The degradation of MB by strain F5 was due to the synergistic effects of laccase (Lac), manganese peroxidase (MnP), lignin peroxidase (LiP), and NADH-DCIP reductase; among them, Lac and MnP were the key enzymes. The phytotoxicity results showed that MB degraded metabolites' toxicity was lower than that of the parent compound, indicating that the strain F5 had a detoxification effect on MB dyes.