Dye Decolourization Research Articles

Response surface methodology mediated optimization of Lignin peroxidase from Bacillus mycoides isolated from Simlipal Biosphere Reserve, Odisha, India

BackgroundLignin is a complex polymer of phenyl propanoid units found in the vascular tissues of the plants as one of lignocellulose materials. Many bacteria secrete enzymes to lyse lignin, which can be essential to ease the production of bioethanol. Current research focused on the study of ligninolytic bacteria capable of producing lignin peroxidase (LiP) which can help in lignin biodegradation and bioethanol production. Ligninolytic bacterial strains were isolated and screened from the soil samples of Simlipal Biosphere Reserve (SBR), Odisha (India), for the determination of their LiP activity. Enzymatic assay and optimization for the LiP activity were performed with the most potent bacterial strain. The strain was identified by morphological, biochemical, and molecular methods. ResultsIn this study, a total of 16 bacteria (Simlipal ligninolytic bacteria [SLB] 1–16) were isolated from forest soils of SBR using minimal salt medium containing lignin. Out of the 16 isolates, 9 isolates showed decolourization of methylene blue dye on LB agar plates. The bacterial isolates such as SLB8, SLB9, and SLB10 were able to decolourize lignin with 15.51%, 16.80%, and 33.02%, respectively. Further enzyme assay was performed using H2O2 as substrate and methylene blue as an indicator for these three bacterial strains in lignin containing minimal salt medium where the isolate SLB10 showed the highest LiP activity (31.711 U/mg). The most potent strain, SLB10, was optimized for enhanced LiP enzyme activity using response surface methodology. In the optimized condition of pH 10.5, temperature 30 °C, H2O2 concentration 0.115 mM, and time 42 h, SLB10 showed a maximum LiP activity of 55.947 U/mg with an increase of 1.76 times from un-optimized condition. Further chemical optimization was performed, and maximum LiP activity as well as significant dye-decolourization efficiency of SLB10 has been found in bacterial growth medium supplemented individually with cellulose, yeast extract, and MnSO4. Most notably, yeast extract and MnSO4-supplemented bacterial culture medium were shown to have even higher percentage of dye decolourization compared to normal basal medium. The bacterial strain SLB10 was identified as Bacillus mycoides according to morphological, biochemical, and molecular (16S rRNA sequencing) characterization and phylogenetic tree analysis. ConclusionResult from the present study revealed the potential of Bacillus mycoides bacterium isolated from the forest soil of SBR in producing LiP enzyme that can be evaluated further for application in lignin biodegradation and bioethanol production. Scaling up of LiP production from this potent bacterial strain could be useful in different industrial applications. Graphical Abstract▪

A rutile phase-TiO2 film via a facile hydrothermal method for photocatalytic methylene blue dye decolourization

In this work, we have fabricated rutile- phase TiO2 film on a fluorine doped tin oxide (FTO) substrate by a facile hydrothermal method and studied for methylene blue (MB) dye decolourization under direct noon sunlight irradiation. The prepared film was characterized by UV–visible spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR), Raman spectroscopy and Field Emission Scanning Electron Microscopy (FESEM). XRD analysis confirms that the hydrothermal treatment facilitated the crystallization of the rutile TiO2 phase on FTO plate. The functional group, surface morphology and structural property were analyzed from FTIR and FESEM respectively. The optical band-gap was evaluated to be 3.2 eV from the UV–visible spectroscopy. The photocatalytic activity of rutile-TiO2 film was evaluated which showed 78 % Methylene blue dye decolourization in 240 min.

Decolourization of Safranine Dye by Iron(II)/HClO4/CAB System from Wastewater Assisted by Response Surface Modeling

The response surface methodology (RSM) is applied for predictive estimation and optimization of decolourization of safranine, a phenazine dye by a chemical oxidation process using iron(II) as homogeneous catalyst and chloramine B (CAB) as an oxidant in acid medium. All experiments were based on the statistical designs in order to develop the predictive regression models and for optimization. Four independent variables (temperature, catalyst, CAB and acid concentration) were chosen to optimize the decolourization of safranine. When variance was analyzed (ANOVA), values of R2 and adjusted R2 were 0.9618 and 0.9262, respectively. The data derived from the experiments were in alignment with a second order regression model. In order to achieve a maximum decolourization, the optimal settings were found to be 0.0178 M HClO4, 0.004 M CAB, 0.0016 M iron(II) and 43.1 ºC, respectively. Under optimal reaction conditions, effect of temperature (15, 25, 35, 45 ºC) on decolourization rate was studied. Data received were in congruence with the second order kinetics. Thermodynamic parameters were also computed for the decolourization process. Maximum percentage of decolourization of safranine was predicted and experimentally validated.

Efficacy of Algae powder (BAST) on uprooting of methylene blue dye (MBD): Optimization

In the present study experimental data was obtained for the removal of Methylene Blue Dye (MBD) by Brown Algae Sargassum tenerrimum (BAST) powder as a biosorbent in batch operation. The equilibrium Agitation time for methylene blue dye (MBD) was obtained at 120 min with percentage removal as 95.74percentage, Optimum dosage observed was 0.1 gm at pH = 6 for the particle size 90 µm. For the decolourisation of methylene blue dye (MBD) both Langmuir and Freundlich isotherm model was well fitted with the R2 values are 0.97 and 0.96 respectively and followed by Tempkin isotherm with R2 is 0.98. The kinetic studies show that the biosorption of methylene blue dye (MBD) is better described by Pseudo-second order kinetics. The Response Surface Methodology (RSM) optimal set of conditions for maximum biosorption of methylene blue dye (MBD) are time = 119.52 min, pH = 5.83, and Biosorbent Dosage = 1.2 g/L. The percentage biosorption of methylene blue is 95.8percentage. The critical values reported by optimization through RSM are very similar to the batch optimum studies values showing that BAST is having better efficiency fir the removal of MBD from aqueous solutions.

IMPACT OF INDUSTRIAL DYES ON ALGAL GROWTH

The deterioration of water quality because of industrial dye discharges is becoming an emerging environmental problem throughout the world. Dyes are directly discharged into nearby water bodies which in turn affect the aquatic ecosystem and human health. Dyes were degraded by means of biological methods. This study involves the application of two algae (Chlorella vulgaris and Spirulina) and oxidation pond in the decolourisation of dyes. The UV spectromax M3 spectrophotometer was used in reading absorbance values. Methylene blue (MB) (20 mg/l, 50 mg/l and 100mg/l), Eriochrome Black T (EBT) (20mg/l, 50mg/l and 100mg/l) and Melanoidin (100mg/l, 250mg/l and 500mg/l) at different concentrations were used for this study. Decolourisation was recorded in a 10-day experiment. In Spirulina, maximum dye removal was 92.37 percent (20mg/l) in methylene blue dye, 54.24 percent (20 mg/l) in EBT and 45.89percent (100mg/l) in melanoidin while in oxidation pond, the maximum dye removal was 91.84 percent (20mg/l) in methylene blue dye, 93.22percent (20mg/l) in EBT and 46.1 percent (100mg/l) in melanoidin and in Chlorella vulgaris, the maximum dye removal was 91.3 percent (20mg/l) in methylene blue dye, 79.25 percent (20mg/l) in EBT and 57 percent (100mg/l) in melanoidin. The dye removal was dependent on algal concentration and dye concentration. Gel puncture method was used to determine the toxicity of individual dyes on algae (Mixed sample, Scenedesmus and Lake Sample) at varying concentration of dyes.

Decolourization of textile dyes and textile industry effluent in a fixed bed biofilm reactor using native microorganisms

Textile and apparel industry plays a huge role in the Sri Lankan industrial sector, accounting more than 40% of export earnings in the country. Textile wet processing produces large volumes of coloured effluents which have potential to cause negative impacts on environment and various adverse health effects if not properly treated.

Decolourization of congo red synthetic dyes by dark septate endophytes

The use of fungi is known to be an eco-friendly and cost-competitive approach to degrade synthetic dyes such as Congo Red (CR) in industrial effluents. This research aimed to evaluate the potential of dark septate endophytes (DSE) fungi in decolourizing CR synthetic dyes. Two DSE strains, namely CPP and KSP, were studied to decolourize 50 mgL−1 CR based on the capability to produce the ligninolytic enzyme, dye decolourization efficiency, decolourization index, and fungal dry biomass weight after 7 and 14 days of incubation. CR decolourization was monitored spectrophotometry at 495 nm. The result indicated that CPP and KSP were successfully decolourized CR dye up to 97.00% and 85.00%, respectively, with decolourization index of 1.37 and 1.36 within 14 days. There is no significant difference in DSE growth with and without the addition of CR dye. In addition, these two DSE fungi (CPP and KSP) are able to produce ligninolytic enzymes. The results indicated that the DSE are potential to be used as decolourization agents for azo synthetic dyes. This is the first report on the ability of DSE to decolourize azo synthetic dyes.

Discovering the roles of electrode distance and configuration in dye degradation and electricity generation in photocatalytic fuel cell integrated electro-Fenton process

• Mass transfer of ions in the PFC-EF system affected by electrode distance. • Closest electrode distance yielded highest power output and degradation efficiency. • Single cathode PFC-EF system was more feasible for dye degradation. • Double cathodes PFC-EF system achieved the highest voltage output. Photocatalytic fuel cell (PFC) integrated electro-Fenton (EF) system (PFC-EF system) was considered as an eco-friendly approach for dye degradation and electricity generation simultaneously. The modification on configuration of PFC-EF system was aimed to improve the dye degradation and power output. Effect of electrode distance on the efficiency of PFC-EF system was investigated as it was a crucial factor in the mass transfer of ions in PFC-EF system. Closer electrode distance reduced the resistance flow of ions and enhanced the mass transfer of ions between the electrodes in both PFC and EF, eventually yielded higher concentration of reactive species for removal of dye. Four different electrode configurations by varying the number of cathodes in PFC and EF were investigated to discover the most efficient operating configuration for this PFC-EF system. The dye decolourization rate was evaluated and compared by using pseudo-first order and second order in both PFC and EF system, respectively. Results revealed that single cathode PFC-EF system was the most effective configuration in dye degradation while double cathodes PFC-EF system was the optimal configuration to be used for power output.

A homemade laboratory applied to the phytoremediation of textile dyes by high school students in the context of the COVID-19 pandemic

ABSTRACT Biosphere contamination is a current environmental and social issue that must be included in the school programme. It is essential that students recognise their responsibility, and be knowledgeable about the generation and reduction of environmental pollution. Dyes are usually used in school activities and discharged into household effluents, constituting potential toxic agents. To offer solutions to this problem, it was proposed to evaluate the ability of Lemna sp. plants to remove synthetic dyes. For this, activities that require accessible resources and minimum safety precautions were designed, which could be carried out by students at home in the virtual education modality imposed by the COVID-19 pandemic. The practical experience integrated theoretical-practical contents from different disciplines, achieving a true interdisciplinary dialogue. The use of Lemna sp. secured a fast and significant dye decolourisation, demonstrating the importance of biodiversity in the attenuation of environmental changes due to anthropogenic activities. This experience allowed us to arrive at an interdisciplinary, significant and situated learning experience through the implementation of the scientific method.

Mathematical modeling and optimization by the application of full factorial design and response surface methodology approach for decolourization of dyes by a newly isolated Photobacterium ganghwense

Dyes are chemicals found in industrial water discharge, which may harm aquatic life and humans. In this study, halophilic bacteria was isolated from sea water in Jeddah, KSA, and then identified using 16SrDNA sequencing technique. Mathematical modeling has been achieved to predict the number of runs needed to reach the maximum of dye removal. Then the effect of four independent variables (NaCl concentration, Peptone concentration, temperature and agitation) was studied using full Factorial Design (FFD) for the determination of optimal abiotic and biotic condition, which reaches a maximum percentage of colour removal (% of decolourization) in artificial seawater (ASW). A model was proposed for the statistical analysis of colour removal prediction. Analytical techniques (UV–vis and FTIR) was also used to determining the degradation mechanisms. The active strain was then genetically characterized to identify genes related to chemical and dyes biodegradation.The isolated strain was identified as Photobacterium ganghwense. Our results revealed that P. ganghwense (5.106 CFU/ mL) was able to decolourize four tested dyes (Methyl orange, Congo red, Crystal violet and Malachite green) in modified ASW with different degrees and the maximum of decolourization was attributed to malachite green (79.61%). The biodegradation capability of the selected strain was confirmed by UV–Vis spectrum and FTIR analysis. Experimental data and model predictions were found to be in good agreement. Genomic analysis confirm the presence of several enzymes (reductase, dehydrogenase, oxidase, kinase, hydrolase, and transferase) associated with dyes and xenobiotic degradation, indicating its possible use in biotechnology applications.

Enterobacter sp. AI1 produced a thermo-acidic-tolerant laccase with a high potential for textile dyes degradation

Biocatalytic decolourisation of synthetic dyes is hindered by the characteristic properties contained in the textile effluents. Cow dung was sampled from the University of Fort Hare farm, Eastern Cape Province, South Africa. The sample was subjected to selective enrichment, and the organism isolated was texted on various phenolic plates and quantitatively examined for laccase activities. The isolate was molecularly identified using 16S rRNA and subjected to extracellular laccase production. Agrowaste and time course were the factored optimised process conditions applied for laccase production. The laccase produced was purified and applied to degrade various synthetic dyes. The primary screening results showed various colour halo zone oxidation on the phenolic plate. The quantitative study gave a laccase activity of 54.71 and 38.21 (U/mL) on ABTS and PFC substrate molecularly identified as Enterobacter sp. AI1. Corn Stover (CS), Banana Peel (BP), and Wheat Bran (WB) optimally gave a laccase yield of 18.47, 18.87, 20.19 (U/mL) with a 12-day laccase yield of 38.25 U/mL. The purified laccase showed a specific activity of 187.88 U/mg of protein and a molecular weight of 75 kDa with a strong affinity for ABTS at 52.27 U/mL laccase activity. Laccase kinetic showed a Km and Vmax value of 0.23 and 51.28 and was optimum at pH4 and at 60 °C. The purified laccase maximally displayed decolourised effect of 78, 85.7, 77, 81, and 73 (%) on Malachite Green (MG), Congo Red (CR), Methyl Orange (MO), Remazol Brilliant Blue R (RBBR), and Reactive Blue 4 (RB4), respectively. The molecular identification Enterobacter sp. AI1 showed it belongs to the class of gammaproteobacterial. Their nucleotide sequence has been deposited in NCBI with the accession number MN686605. Conclusively, cow dung served as a rich source for isolating ligninolytic bacteria with active bioactive compounds applicable to bioprocess control.

Transition metals doped WO3 photocatalyst towards high efficiency decolourization of azo dye

Tungsten oxide semiconductor (WO3) modified using transition metals (Ni, Fe, and Zn) was synthesized via microwave-assisted solution combustion method. Ni, Fe, and Zn were doped in the WO3 structure to improve the photocatalytic efficiency. The prepared powders were characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy analysis to investigate products' structural and morphological properties and surface composition. The materials show a monoclinic structure of WO3 with small shifts in the peak position for each catalyst. Reactive blue 194 (RB 194) aquatic solution was used for photodegradation experiments under UV irradiation to evaluate the photocatalytic properties. The results showed an improvement in photocatalytic activity of host structure within doping the iron and nickel, whereas adding zinc made a decline in decolorization efficiency of WO3. The photocatalytic performance of samples is in the order of WO3:Ni > WO3:Fe > WO3 > WO3:Zn. The influences of operational parameters were evaluated for each catalyst to obtain the optimum conditions of the photocatalytic reaction.

Kinetic studies of photocatalytic degradation of an Azo dye by titania nanoparticles

Purpose Dyeing and printing are important steps in textile manufacturing. After the process completion, these dyes are released in the effluent. These dyes impart an unacceptable appearance but are also toxic to the soil and water bodies. The present research has been carried out to study the rate of photocatalytic degradation of an azo dye, namely, CI Direct Green 26, using titania nanoparticles under ultra violet (UV) irradiation as a function of temperature and time. Azo dyes account for the majority of all dyestuffs are produced and extensively used in the textile, paper, food, leather, cosmetics and pharmaceutical industries. Titania nanoparticles have been found to successfully degrade these dyes in the presence of UV light. The purpose of the present paper was to study the photodegradation of azo dyes using titania nanoparticles at different temperatures and time periods. Design/methodology/approach Titania nanoparticle concentration of 0.1% (w/v) was dispersed in distilled water by sonication for 1 h in sonication bath. The of rate of degradation of Direct Green 26 dye in the titania nanoparticle dispersion, under UV-A exposure was studied at different temperatures ranging from 25°C to 65 °C for time periods ranging from 1 h to 6 h. Photocatalytic degradation tests were performed in a specially designed UV reactor chamber. Raman spectroscopy of Titania nanoparticles, dye and titania/dye mixture before and after UV exposure was carried out using Confocal Laser Dispersion Raman Microscope (Renishaw, UK) with 785 nm excitation laser. Findings Titanium dioxide is an efficient photocatalyst for decolourisation of direct dye. The photodegradation of the direct Green dye was found to follow the pseudo first-order reaction. The Arrhenius activation energy was found to be 24.8 kJ/mol with A value of 0.0013 for the photocatalytic degradation of the dye. Raman spectroscopy also confirmed the adsorption of dye on titania nanoparticle and its complete degradation on exposure to UV light. Practical implications This research highlights the application of titania nanoparticles for the effective degradation of dye in the effluent from textiles, clothing, paper and any kind of dyeing process. Azo dyes account for the majority of all dyestuffs are produced and extensively used in the textile, paper, food, leather, cosmetics and pharmaceutical industries. Titania nanoparticles have been found to successfully degrade these dyes in the presence of UV light which can be very beneficial for the effluent treatment plants in textile and other industries. Originality/value Azo dyes are one of the harmful pollutants released in textile waste water. The degradation and removal of the coloured waste in the textile effluent is an important environmental concern and needs to be investigated. The research is one of the first to investigate and understand the mechanism of the degradation of an azo dye in the presence of titania nanoparticles by Raman spectroscopy.

Decolourization of azo dye using a batch bioreactor by an indigenous bacterium Enterobacter aerogenes ES014 from the waste water dye effluent and toxicity analysis

Effluents of textile industries caused serious environmental problem throughout the world. In this study, a total of 23 bacterial strains from five bacterial species were isolated from the dye effluent. Of these strains, a unique and novel Enterobacter aerogenes ES014 was utilized for dye decolourization and toxicity analysis. The selected strain could effectively decolourize three selected azo dyes. It showed the capability for decolourizing acid orange (82.3 ± 3.6%), methyl orange (78.2 ± 3.3%), and congo red (81.5 ± 3.2%). The selected bacterial strain significantly decolourized 100 mg/L acid orange at 35 °C, pH 7.5 with 6% sodium chloride concentration. Most of the tested nitrogen and carbon sources effectively enhanced decolourization process. It showed the ability to decolourize acid orange in the culture medium containing 1.5% glucose (100 ± 2.8%) and 0.8% beef extract (100 ± 3.1%). A laboratory-scale batch bioreactor was used to decolourize azo dye at optimized culture conditions. The decolourizing ability improved with 100 mL/h hydraulic retention time. The treated wastewater quality was improved due to sharp depletion of Total Dissolved Solids (TDS), pH, Chemical Oxygen Demand (COD), alkalinity and sulphate concentration. The selected bacteria has the potential to produce dye degrading laccase. Laccase was detected during fermentation process in batch bioreactor as a key enzyme for decolourization produced by E. aerogenes ES014. Phytotoxicity and acute toxicity analysis were performed using Arachis hypogaea (pea nut) seed and first instar larvae of Artemia parthenogenetica (brine shrimp). The seed germination rate of treated wastewater was improved (94.3 ± 1.8%) and enhanced survival rate (91.7 ± 2.9%) in the first instar Artemia larvae treated with wastewater after 24 h. Overall, E. aerogenes ES014, might be a promising bacterial strain for the treatment of textile effluents with high azo dye concentrations.

Structural and optical properties of MgNb2O6 NPs: Its potential application in photocatalytic and pharmaceutical industries as sensor

Present research accounts for the production of columbite type MgNb2O6 nanoparticles (MNO NPs) by solution combustion method, its application in photocatalytic degradation and electrochemical sensor studies. The resultant nanoparticles were well characterized by Powder X-ray diffraction (PXRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and UV–Visible (UV–Vis) spectral studies. PXRD patterns showed that nanoparticles have orthorhombic phase with average crystallite size of ∼29 nm.The energy band gap of the sample was found to be 4.4 eV by Diffused reflectance spectroscopy (DRS) analysis. The MNO photocatalyst matrix influences excellent photocatalytic decolourization of Acid Red-88 (AR-88) and Fast orange red (FOR) dyes under UV light irradiation. The experiment show 86 % and 74 % dye decolourization respectively after 120 min irradiation. The holes (h+) are mainly responsible for excellent photocatalytic activities as confirmed by scavenger test. Electrochemical analysis was carried out to find the reversibility of the electrode reaction of electrode using 0.1 M KCl by Cyclic voltammetry (CV) and Electrochemical impedance spectroscopy (EIS) analysis. Thus, the prepared sample plays an excellent role in photocatalysis, electrochemical activity and chemical sensing applications.

Advanced oxidation treatment of amaranth dye synchronized with electricity generation using carbon-based cathodes in a sustainable photocatalytic fuel cell integrated electro-fenton system

Cathodes are key components in the photocatalytic fuel cell (PFC) integrated electro-Fenton (EF) system (PFC-EF system) as they play significant role in connecting PFC and EF for the external transfer of electrons. In this study, three ubiquitous carbon-based materials (carbon felt (CF), carbon plate (CP) and carbon cloth (CC) were used as cathodes in the PFC-EF system to explore the efficiency of these materials in Amaranth degradation and electricity generation synchronously. Interestingly, the dye decolourisation efficiency in both PFC and EF decreased in the sequence of CF > CP > CC. The highest concentration of hydrogen peroxide (0.289 mM) was electro-generated on CF in the EF process of the integrated system. CF achieved the highest voltage output of 202.6 mV and maximum power density (Pmax) of 3.560 μW cm-2, which was 2.5-fold and 12.1-fold higher than that of CP and CC, respectively. The photolysis reaction of UV contributed to the higher oxidizing power of PFC integrated photo-electro-Fenton (PEF) system in dye degradation compared with that of the existing PFC-EF system. Enhanced decolourisation efficiencies of 98.97% and 96.46% were respectively achieved in PFC and PEF with Pmax of 4.017 μW cm-2.

Characterisation and optimisation of a novel laccase from Sulfitobacter indolifex for the decolourisation of organic dyes

Laccases are multi‑copper oxidases that possess the potential for industrial wastewater treatments. In this study, a putative laccase from Sulfitobacter indolifex was recombinantly produced and characterised. The enzyme was found to be stable and active at low to ambient temperature and across a range of pH conditions. The ability of the putative bacterial laccase to catalyse the decolourisation of seven common industrial dyes was also examined. Our results showed that the putative laccase could efficiently decolourise Indigo Carmine, Coomassie Brilliant Blue R-250, Congo Red, Malachite Green and Alizarin in the presence of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) as a redox mediator. Furthermore, the use of enzyme immobilisation technology to improve the operational stability and reusability of the putative laccase was also investigated. We found that immobilising the enzyme through the cross-linked enzyme aggregate method significantly improved its tolerance towards extreme pH as well as the presence of organic solvents. This work expands the arsenal of bacterial laccases available for the bioremediation of dye-containing wastewater.

Mycoremediation for Decolourization of Dye in Wastewater Using Fungi Consortium Culture: A Review

Dye is extensively used in industries, such as textile, paper printing, food, and leather. Dye causes significant effects on living organisms and the environment. Current dye treatment methods are inefficient in decolourization as the dye is highly persistent. Efficiency in the decolourization of dye is a challenge for industries as well as for wastewater treatment systems. This paper focuses on the mycoremediation dye treatment method, a sustainable treatment method that leads to green technology. This study explores mycoremediation efficiency and processes for dye decolourization. The gap of study on fungal mixed culture shapes future study direction of dye decolourization. Synergistic or antagonistic effects of mixed culture towards dye decolourization should be further investigated.

Decolourization of malachite green dye by endolichenic fungi from the lichen Usnea sp.: A novel study on their dye removal potential

ObjectiveThis novel study explored the potential of two endolichenic fungi, Pseudopestalotiopsis theae (PT, accession number MG881833) and Astrocystis bambusae (AB, accession number MH370741) in decolorizing Malachite Green (MG). MethodsTheir efficacy in dye decolorization was compared to non-endolichenic fungus Trichoderma asperellum (TA, accession number KP792512). Decolorization test was performed using MG (100 ppm) for 14 days (absorbance at 617 nm) to determine decolorization efficiency (DE, %). The pellet was collected for FTIR analysis (4000 to 700 cm−1, 50-scan speed) while the supernatant was analysed with UV-spectral analysis (300–800 nm) to detect for biodegradation. ResultsP. theae demonstrated the highest decolorization efficiency (DE%) at 89.22%, followed by T. asperellum (76.19%) and A. bambusae (67.69%). Common functional groups (i.e., OH, COOH, NH, CH, CO, CH) were detected in all isolates and their roles in biosorption were evident by the shifts in peaks and peak intensity. Biodegradation of MG was concluded based on UV-spectra peaks at 617 nm, which were significantly reduced (or absent). ConclusionThis study is the first to reveal that endolichenic fungi P. theae and A. bambusae are capable of decolorizing the toxic dye malachite green.

Electro-oxidative Decolouration and Degradation of Amaranth Dye Wastewater in Batch Setup using Novel Ti/TiO2-Ru2O-IrO2 Anode

In this work, electro-oxidation of amaranth dye wastewater has been performed using dimensionally stable anode (DSA) and stainless-steel cathode. Ti/TiO2-Ru2O-IrO2 ternary electrode was used as the anode. Effect of various parameters such as current density, pH, voltage and time on the degradation and decolouration of dye was studied. Optimum conditions for the treatment of dye wastewater in batch setup were found. The complete decolouration was achieved in the first 5 min of the process. Decolouration and degradation of amaranth dye wastewater followed pseudo-first-order kinetics. The present research work unlocks the new horizon towards the degradation of dye wastewater employing the once through continuous process.