Conditions For Decolorization Research Articles

Research on the refining and decolorization process of segmented tallow

Using segmented tallow as the experimental material, processed to obtain segmented tallow, and exploring the refining and decolorization process of segmented tallow. Firstly, the orthogonal experimental analysis method was used to investigate the effects of three single factors, namely heating temperature, heating time, and heating speed, on the sensory perception of refined segmented tallow; Secondly, study the decolorization effect of silica gel, activated clay, and attapulgite as decolorizing agents on the segmentation of tallow. The optimal conditions of decolorizing agent for segmenting tallow and oil were systematically investigated from the aspects of decolorizing agent dosage, decolorizing temperature, and decolorizing time. The results showed that under the same conditions, the decolorizing effect of activated clay was the best; Finally, response surface methodology was used to investigate the optimization of three single factors, namely the amount of decolorizing agent, decolorization temperature, and decolorization time, on the decolorization of segmented tallow and fat, in order to obtain the optimal decolorization conditions. The experimental results show that the optimal refining conditions are: heating temperature of 165℃, heating time of 85 minutes, and heating speed of 510 r/min. After sensory evaluation data, the optimal sensory score obtained under these refining conditions is 8.6; Under the conditions of active clay dosage of 3.7%, decolorization temperature of 81℃, and decolorization time of 17 minutes, the decolorization rate of segmented tallow can reach 71.9%.

Preparation and decolorization of sapindus mukurossi extract and its application in sebum-control shampoos

BackgroundSapindus mukurossi extract (SME) is a kind of natural surface active ingredient with potential applications in cleansing products. However, the polyphenols and pigments contained in the extract may cause color browning of the products during storage especially at elevated temperatures, affecting its high level addition in the products. ObjectiveTo explore a decolorization process suitable for industrialization realize the high level addition of SME and explore the potential of SME in the field of controlling sebum esters. Materials and MethodsSME was prepared by adsorbing polyphenols on the D301 resin and oxidation decoloring oxidation. Investigated its sebum-control efficacy by SZ95 model and clinical study. ResultsThe results demonstrate that the D301 resin displays the best adsorption selectivity for polyphenols in SME, and the polyphenol adsorption ratio of D301 resin (5 wt%) can reach 83.6%; The optimal decolorization conditions are pH= 7.8, temperature 73 ℃ and decolorization time 5.7 h when H2O2 content is 6%, The prepared SME shows no obvious changes in color and retain stable during the high temperature (50 °C) test period of 28 days. 4 μg/mL of SME decreases the lipid synthesis of SZ95 cells by 24.8%. The clinic efficacy of the shampoo containing 10% SME (by dry extract weigh) is further evaluated. No significant changes in the skin moisture content and transepidermal water loss (TEWL) are observed within four weeks after using the product, while the scalp sebum level is significantly reduced. ConclusionIn this study, we prepared a light-colored, highly stable SME, enabled its high-level addition in cleansing and care products and found its sebum-control efficacy.

Efficient Decolorization of the Poly-Azo Dye Sirius Grey by Coriolopsis gallica Laccase-Mediator System: Process Optimization and Toxicity Assessment.

The textile industry produces high volumes of colored effluents that require multiple treatments to remove non-adsorbed dyes, which could be recalcitrant due to their complex chemical structure. Most of the studies have dealt with the biodegradation of mono or diazo dyes but rarely with poly-azo dyes. Therefore, the aim of this paper was to study the biodegradation of a four azo-bond dye (Sirius grey) and to optimize its decolorization conditions. Laccase-containing cell-free supernatant from the culture of a newly isolated fungal strain, Coriolopsis gallica strain BS9 was used in the presence of 1-hydroxybenzotriazol (HBT) to optimize the dye decolorization conditions. A Box-Benken design with four factors, namely pH, enzyme concentration, HBT concentration, and dye concentration, was performed to determine optimal conditions for the decolorization of Sirius grey. The optimal conditions were pH 5, 1 U/mL of laccase, 1 mM of HBT, and 50 mg/L of initial dye concentration, ensuring a decolorization yield and rate of 87.56% and 2.95%/min, respectively. The decolorized dye solution showed a decrease in its phytotoxicity (Germination index GI = 80%) compared to the non-treated solution (GI = 29%). This study suggests that the laccase-mediator system could be a promising alternative for dye removal from textile wastewater.

Activated carbons from open air and microwave-assisted impregnation of cotton and neem husks efficiently decolorize neutral cotton oil

The decolorization of cottonseed oil with activated carbons (ACs) from neem and cotton husks has a dual interest: elimination of undesirable pigments in oil and valorization of the husks; by-products of neem and cottonseed processing, which would otherwise be dumped along riverbanks and farms causing environmental pollution. ACs were produced from neem and cottonseed husks after acid impregnation assisted by microwave heating and in ambient air for the decolorization of neutral cottonseed oil. The experimental data were analyzed by the intraparticle diffusion and the pseudo-second-order kinetic models as well as the Langmuir and Freundlich isotherm models. The method of impregnation and carbonization time had dramatic effects on the specific surface area (800–1500 g/m2), the quantity of burn-off (50–70 %), and methylene blue index (300–5000 mg/g) values which indicated the potential of the prepared activated carbons in the bleaching of vegetable oil and in other applications such as environmental clean-up and in agriculture. Pigment adsorption increased with temperature for all ACs indicating that the decolorization process was endothermic. The quantity of adsorbent equally had a significant effect on the pigment adsorption process for all ACs. All the activated carbons prepared in this work were 30–80 % more efficient in pigment adsorption than bleaching earth that is normally used in decolorizing neutral cotton seed oil in industries. All tested models are adequate to describe pigment adsorption by the ACs. Both methods of preparation of ACs were effective for oil decolorization, but microwave impregnation is more appealing because it requires only 1 h compared to 6 h for ambient air. Optimum decolorization conditions were 90 °C for 40min and adsorbent concentration of 2 %.

Removal of reactive dyes from textile industrial effluent using electrocoagulation in different parametric conditions of aluminum electrodes

Untreated textile industrial effluent becomes a major concern for the receiving water bodies. Extensive use of azo dyes in textile industries trigger to find latest techniques for the treatment of textile wastewater. The purpose of this study was to employ the electrocoagulation process for the effective removal of dyes from textile wastewater. The optimization of parameters was performed using the Taguchi method to analyze the conditions of electrode for efficient dye removal. The effects of different parameters including synthetic dye initial concentration, initial pH, applied voltages, interelectrode distance and contact time were studied. Different electrode pairs combination with iron to iron, iron to aluminum and aluminum to aluminum were investigated. The electrode combination of aluminum to aluminum performed better in terms of dye removal. The removal efficiency of methylene blue was achieved to 82% under optimum conditions having pH of 8, 15 V voltage, 60 min contact time and 2 cm aluminum interelectrode distance. Similarly, the optimum conditions for decolorization of methyl orange was performed and achieved 81% of removal efficiency. After the optimization of electrode and parametric conditions, real textile wastewater was treated and removal efficiency of 81% was achieved. At optimal conditions (pH 7–8, 15 V, 60 min contact time, and 20 min settling time), COD, TDS, TSS, and discoloration removal efficiencies were 79%, 91%, 75%, and 86%, respectively. The result of this study indicates the significance of EC process and its future scope for integration of this technology at industrial scale.

Ultrafiltration associated with microporous resin decolorizing the Bacillus subtilis fermentation broth for the production of γ-polyglutamic acid

Abstract Currently, the industrial production of γ-polyglutamic acid (γ-PGA) was mainly based on microbial fermentation, but the decolorization technology still needs to be improved. Therefore, in this study, the optimal decolorization conditions and efficiencies were investigated. As the result, D4006 was an ideal resin for the decolorization of γ-PGA fermentation broth. The optimal decolorization pH value and temperature were pH 3 and 40 °C, respectively; ultrafiltration differential pressure, temperature and time were 0.2 MPa, 40 °C, and 6 h, respectively. Moreover, the combination of D4006 (3 %) resin on the basis of ultrafiltration had a better decolorization effect on γ-PGA fermentation broth, and the decolorization rate reached 96.8 %.

The Biosynthesis of Nickel Oxide Nanoparticles: An Eco-Friendly Approach for Azo Dye Decolorization and Industrial Wastewater Treatment

Wastewater is one of the major concerns for agriculture, and the composition of wastewater depends on its origin. Generally, industrial wastewater consists of azo dyes and heavy metals that contaminate the food chain. In this study, nickel oxide nanoparticles (NiO-NPs) were biosynthesized from Shewnella spp. and characterized by UV–visible spectroscopy (UV–vis), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Azo dye decolorization indicated that NiO-NPs decolorize methylene blue (MB) (82.36%), Congo red (CR) (93.57%), malachite green (MCG) (91.05%), reactive black 5(RB5) (55.17%), reactive red-II(RR-II) (55.45%), and direct blue-I(DB-I) (59.94%) at a dye concentration of 25 mg L−1 after 4 h of sunlight exposure. Additionally, the rate of decolorization was also examined for a 50 mg L−1 concentration of dye. In order to investigate the photocatalytic potential of NiO-NPs, different dyes were also subjected to static and shaking conditions for dye decolorization. The treatment of industrial wastewater with NiO-NPs showed a significant reduction in pH from 8.5 to 6.1, EC (48.38%), chemical oxygen demand (49.24%), total dissolved solids (67.05%), sulfates (52.5%), and phosphates (49.49%). The results of this study indicated that biosynthesized NiO-NPs are an attractive choice for azo dye degradation and industrial wastewater treatment, and they can help save the depleted natural resources of water for agricultural purposes.

Evaluation of Bioremediation Potentiality of Bacillus mojavensis Isolated from Wastewater for the Elimination of Reactive Yellow 145 and Methyl Orange.

Textile industry waste has become one of the largest polluters in the world. In recent years, there has been a growing awareness of the need for sustainable and eco-friendly practices for the treatment of dye-laden effluents. Overall, this study highlights the potential of bioremediation as a sustainable solution for wastewater treatment. The Bacillus mojavensis isolated from wastewater and identified using 16S rRNA degraded reactive yellow 145 and methyl orange in 36h of incubation, this decolorization was affected by pH, temperature, dye concentration, glucose concentration, source of nitrogen, type of dye, and agitation. Our study found that the optimal conditions for total decolorization of dyes were achieved by incubating B. mojavensis at 46°C, pH 9, with 1g/L of glucose and 2g/L of peptone. The azoreductase activity, FT-IR analysis, and UV-visible spectrum before and after total decolorization indicated that it was a dye degradation rather than biosorption in surface Celle. In addition, the study of phytotoxicity show the metabolites of degradation are not phytotoxic in Lens esculenta seeds. In conclusion, our results suggest the use of this bacterium as an environmentally friendly and also cost-effective method, making it an attractive option for industries looking to reduce their environmental impact.

A Potentially Practicable Halotolerant Yeast Meyerozyma guilliermondii A4 for Decolorizing and Detoxifying Azo Dyes and Its Possible Halotolerance Mechanisms.

In this study, a halotolerant yeast that is capable of efficiently decolorizing and detoxifying azo dyes was isolated, identified and characterized for coping with the treatment of azo-dye-containing wastewaters. A characterization of the yeast, including the optimization of its metabolism and growth conditions, its detoxification effectiveness and the degradation pathway of the target azo dye, as well as a determination of the key activities of the enzyme, was performed. Finally, the possible halotolerance mechanisms of the yeast were proposed through a comparative transcriptome analysis. The results show that a halotolerant yeast, A4, which could decolorize various azo dyes, was isolated from a marine environment and was identified as Meyerozyma guilliermondii. Its optimal conditions for dye decolorization were ≥1.0 g/L of sucrose, ≥0.2 g/L of (NH4)2SO4, 0.06 g/L of yeast extract, pH 6.0, a temperature of 35 °C and a rotation speed of ≥160 rpm. The yeast, A4, degraded and detoxified ARB through a series of steps, relying on the key enzymes that might be involved in the degradation of azo dye and aromatic compounds. The halotolerance of the yeast, A4, was mainly related to the regulation of the cell wall components and the excessive uptake of Na+/K+ and/or compatible organic solutes into the cells under different salinity conditions. The up-regulation of genes encoding Ca2+-ATPase and casein kinase II as well as the enrichment of KEGG pathways associated with proteasome and ribosome might also be responsible for its halotolerance.

Rehmannia glutinosa Polysaccharides: Optimization of the Decolorization Process and Antioxidant and Anti-Inflammatory Effects in LPS-Stimulated Porcine Intestinal Epithelial Cells.

Polysaccharide decolorization has a major effect on polysaccharide function. In the present study, the decolorization of Rehmannia glutinosa polysaccharides (RGP) is optimized using two methods-the AB-8 macroporous resin (RGP-1) method and the H2O2 (RGP-2) method. The optimal decolorization parameters for the AB-8 macroporous resin method were as follows: temperature, 50 °C; macroporous resin addition, 8.4%; decolorization duration, 64 min; and pH, 5. Under these conditions, the overall score was 65.29 ± 3.4%. The optimal decolorization conditions for the H2O2 method were as follows: temperature, 51 °C; H2O2 addition, 9.5%; decolorization duration, 2 h; and pH, 8.6. Under these conditions, the overall score was 79.29 ± 4.8%. Two pure polysaccharides (RGP-1-A and RGP-2-A) were isolated from RGP-1 and RGP-2. Subsequently, their antioxidant and anti-inflammatory effects and mechanisms were evaluated. RGP treatment activated the Nrf2/Keap1 pathway and significantly increased the activity of antioxidant enzymes (p < 0.05). It also inhibited the expression of pro-inflammatory factors and suppressed the TLR4/NF-κB pathway (p < 0.05). RGP-1-A had a significantly better protective effect than RGP-2-A, likely owing to the sulfate and uronic groups it contains. Together, the findings indicate that RGP can act as a natural agent for the prevention of oxidation and inflammation-related diseases.

Bio-decolorization of synthetic dyes by a novel endophytic fungus Penicillium janthinellum LM5 from blueberry pulp

Synthetic dyes from textile, paper, leather, and plastic processing, etc. are the majority of the colored effluents and have a harmful impact on human health and environment. Dye biosorption through endophytic fungi will be a challenge. A new fungus isolated from blueberry pulp was identified morphologically and genetically as Penicillium janthinellum LM5. It was utilized for the biosorption of synthetic dyes by forming mycelium particles with efficient decolorization properties in the dye solution. The results of decolorization experiments exhibited that dye type, pH, temperature and time were the important factors and the best decolorization condition on Congo red was pH 6.0, 30 ℃ and 48 h. Moreover, LM5 can achieve 90% decolorization rate even under the high salt concentrations of 200 mg/mL. Based on spectral analysis, the decolorization of Congo red was mainly attributed to the biosorption of mycelium and its pellet structure. Additionally, the fungus adsorbed Congo red can be as an excellent electrode material with a long-cycle performance and stable capacitance property, being a good way for recycling. In summary, this research employed a novel dye treatment method with simultaneous culture and decolorization through an endophytic fungus LM5, being a promising biomaterial in the application of dye wastewater treatment.

Decolorization and degradation of methylene blue by photo-Fenton reaction under visible light using an iron-rich clay as catalyst: CCD-RSM design and LC-MS technique

In this work, an iron-rich bentonite was thermally modified at 200 oC and posteriorly used as a heterogeneous catalyst in the decolorization and degradation of methylene blue dye (MB) by photo-Fenton reaction under visible irradiation. The variables such as catalyst concentration and pH were investigated in the reaction system to detect the optimal decolorization conditions using the response surface methodology (RSM) coupled with Central Composite Design (CCD). Photodegradation of MB was analyzed by LC-MS technique. The results indicated that the optimal conditions to obtain 94% of MB decolorization efficiency were pH = 2.4 and catalyst mass = 0.02 g. It was also possible to verify that the simultaneous combination of catalyst, hydrogen peroxide and visible light in the reaction medium was primordial for the increasing MB decolorization efficiency. MB degradation occurred partially at 180 min of photo-Fenton reaction, since the presence of dye in the solution was reduced, leading to its transformation into different intermediate products. Therefore, the catalyst used in this work has demonstrated a great potential for the degradation of cationic dye, allowing its use in advanced oxidation processes

Static decolorization of polysaccharides from the leaves of Rhododendron dauricum: Process optimization, characterization and antioxidant activities

In this study, polysaccharides from the leaves of Rhododendron dauricum L. (RDPs) were decolorized using the static macroporous resin adsorption method. The RDPs were characterized and their antioxidant activities were investigated. An analytical hierarchy process (AHP) and a response surface method (RSM) were used to determine the optimum decolorization conditions as: a polysaccharide concentration of 8 mg/mL, decolorization time of 70 min, liquid–solid ratio of 6 mL/g, and decolorization temperature of 52 °C, with D101 as the best resin. Furthermore, two novel polysaccharides (RDP-1 and RDP-2) were isolated from R. dauricum leaves and characterized, which demonstrated that RDP-1 and RDP-2 were both composed of mannose, glucose, galactose, and arabinose in different molar ratios. These RDPs also exhibited a triple helix conformation, and primarily contained →6)-Glcp-(1→, →5)-Araf-(1→, →2,4)-Manp-(1→, →6)-Galp-(1→ and Glcp-(1→ residues with different connection sequences. Biological activity tests showed that the two polysaccharides possessed scavenging capacity against 1,1-Diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and 2,2-Azino-bis-(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) radicals. The results indicated that the antioxidant activities of the RDPs obtained by the static decolorization method improved, which lays a theoretical foundation for developing techniques for utilising R. dauricum.

Green synthesis of copper oxide nanoparticles CuO NPs from Eucalyptus Globoulus leaf extract: Adsorption and design of experiments

The study is concerned with synthesizing copper oxide nanoparticles with leaf extract Eucalyptus Globoulus . The results of scanning electron microscopy (SEM) and dynamic light scattering (DLS) revealed that the green synthesized copper oxide nanoparticles are spherical and have a mean particle size of 88 nm, with a negative zeta potential of −16.9 mV. The XRD graph showed the crystalline and monoclinic phases of CuO nanoparticles. The average crystalline size around 85.80 nm was observed by the Debye–Scherrer formula. The adsorption characteristics of the nano-adsorbents were investigated using methyl orange, and the adsorption efficiency at room temperature attained 95 mg/g. Copper oxide nanoparticles (CuO NPs) adsorb methyl orange dye most effectively at pH 4.5 when the dye is applied in quantities of 0.04 g/50 mL. Box–Behnken design (BBD) in response surface methodology (RSM) was used to optimize various process parameters, such as pH solution (X 1 : 2 – 11), adsorbing dose (X 2 : 0.01 – 0.08 g/L), [MO] dye concentration (X 3 : 10 – 80 mg/L). Overall, the adjusted coefficient of determination (R 2 ) value of 0.99 demonstrated that the used model was quite appropriate, and the chosen RSM was effective in optimization the decolorization conditions of MO.

Efficient decolorization and detoxification of azo dyes by a halotolerant yeast Meyerozyma guilliermondii A3 with relatively low external carbon source

Decolorization and detoxification of azo dyes by a newly isolated halotolerant yeast was investigated in the present study. This work included isolation and identification of the halotolerant yeast, optimization of its growth and decolorization conditions, proposal of dye decolorization pathways, and analysis of the transcriptomic responses to dye and salt stress. The results showed that a halotolerant yeast which was capable of efficiently decolorizing various azo dyes under saline conditions was isolated and identified as Meyerozyma guilliermondii (strain A3). The optimal conditions for dye decolorization and yeast growth were as follows: glucose (sucrose was also suitable) ≥1.0 g/L, (NH4)2SO4 ≥ 0.2 g/L, yeast extract ≥0.04 g/L, salinity (NaCl concentration) ≤30.0 g/L, temperature 30-35 °C, pH 6.0–7.0 and rotation speed ≥160 rpm. The target dye Acid Red B (ARB) was significantly detoxified by the yeast A3 intracellularly through the processes including cleavage of azo bonds, ortho-hydroxylation (monooxygenation pathway), oxidative desulfurization/deaminization, ring opening of substituted naphthalene, and TCA cycle. Genes encoding oxidoreductases and sugar transporters were universally up-regulated under dye stress, and those encoding cell wall regulators were also up-regulated under salt stress. Meanwhile, genes encoding oxidoreductases and sugar transporters were universally down-regulated under salt stress.

Decolorization of an aqueous solution of methylene blue using a combination of ultrasound and peroxate process

For oxidative decolorization of an aqueous solution of methylene blue (MB), the “Sonoperoxate” process, a combination of ultrasonic (US) irradiation and “Peroxate” process, – US/H2O2/KIO4 was used in the current work. In order to minimize the costs of oxidants, energy consumption, and reduce the duration of decolorization, the studies were performed to understand the influence of the molar ratio MB:H2O2:KIO4, the MB initial concentration, the ultrasonic power, and the pH value of the initial solution on the decolorization of MB. The best conditions for decolorization of an MB aqueous solution using the “Sonoperoxate” process have been established as initial MB concentration of 62.6 μM, the molar ratio MB:H2O2:KIO4 of 1:100:25, pH of 4.00, US power of 60 W and the decolorization duration of 300 s. Under these conditions, the decolorization extent was quite high (95.6%). An increase in the processing duration to 3600 s led to a marginal increase in the decolorization extent of MB to 98.2%. The rate constants of the processes US/H2O2, US/KIO4, H2O2/KIO4, and US/H2O2/KIO4 were used to calculate the value of the synergetic coefficient for the hybrid process, US/H2O2/KIO4. The obtained synergetic coefficient was 3.25 at the molar ratio MB:H2O2:KIO4 as 1:100:25, and 1.62 at the molar ratio of 1:200:50 indicating the dominant contribution of KIO4. The effect of ultrasound as an activator of oxidants (periodate, hydrogen peroxide) has been conclusively established in the current work.

Optimization of the decolorization conditions of Rose Bengal by using Aspergillus niger TF05 and a decolorization mechanism.

Aspergillus niger TF05 was applied to decolorize Rose Bengal dye. The effects of carbon source, nitrogen source, metal ion and spore concentration on Rose Bengal treatment with A. niger TF05 were studied. A Plackett–Burman design (PBD) and a uniform design (UD) were used to optimize the decolorization conditions of A. niger TF05 and enhance its decolorization effect. The mechanism of Rose Bengal decolorization by A. niger TF05 was examined by analysing degradation products via UV–visible light spectroscopy, IR spectroscopy and GC-MS. The best decolorization effect was achieved in the single factor test with glucose and ammonium chloride as carbon and nitrogen sources, respectively. Mg2+ was an essential ion that could improve the mould ball state and adsorption efficiency if the spore concentration was maintained at 106 spores ml–1. The optimal decolorization conditions obtained using the PBD and UD methods were 11.5 g l−1 glucose, 6.5 g l−1 ammonium chloride, 0.4 g l−1 magnesium sulphate, pH 5.8, 28 °C, 140 r.p.m. rotational speed, 0.18 g l−1 dye concentration, 0.5 ml of inocula and 120 h decolorization time. Under these conditions, the maximum decolorization rate was 106%. Spectral analysis suggested that the absorption peak of the product changed clearly after decolorization; GC-MS analysis revealed that the intermediate product tetrachlorophthalic anhydride formed after decolorization. The combined use of the PBD and UD methods can optimize multi-factor experiments. A. niger TF05 decolorized Rose Bengal during intracellular enzymatic degradation after adsorption.

Decolorization of the benzidine-based azo dye Congo red by the new strain Shewanella xiamenensis G5-03.

Shewanella xiamenensis G5-03 was observed to decolorize the azo dye Congo red in synthetic wastewater. The influence of some factors on the dye decolorization efficiency was evaluated. The optimal decolorization conditions were temperature 30-35 °C, pH 10.0, incubation time 10 h, and static condition. The kinetic of Congo red decolorization fitted to the Michaelis-Menten model (Vmax = 111.11 mg L-1 h-1 and Km = 448.3 mg L-1). The bacterium was also able to degrade benzidine, a product of azo bond breakage of the Congo red, which contributed to reduce the phytotoxicity. The ability of S. xiamenensis G5-03 for simultaneous decolorization and degradation of Congo red shows its potential application for the biological treatment of wastewaters containing azo dyes.

Preparation and Photocatalysis of CuO/Bentonite Based on Adsorption and Photocatalytic Activity.

A CuO/bentonite composite photocatalyst was prepared to fully utilize the adsorption capacity of bentonite and the photocatalytic activity of CuO. CuO and bentonite were chosen as a photocatalyst due to the excellent optical property of CuO and large specific surface area of bentonite, together with their high stability and low production cost. The sample was characterized by XRD, SEM, and BET. The effects of several factors on degradation process were investigated such as dosage of H2O2, irradiation time, pH of the solution, and dosage of catalyst. The optimum conditions for decolorization of methylene blue solution by CuO/bentonite were determined. Under optimal conditions, the decolorization efficiency of methylene blue by a 1.4% CuO/bentonite (400 °C) composite photocatalyst under visible irradiation at 240 min reached 96.98%. The degradation process follow edpseudo-second-order kinetics. The photocatalytic mechanism is discussed in detail. This composite structure provides a new solution to the cycle and aggregation of the photocatalyst in water.

Decolorization and degradation of reactive orange 16 by Bacillus stratosphericus SCA1007.

Efficient bacterial strain was isolated from the dye contaminated area and identified as Bacillus stratosphericus SCA1007 based on 16S rRNA genesequence (GenBank under accession number KY992944). This isolate was selected based on its potential to efficiently decolorize reactive orange 16 dye which is extensively used in textile industries. Various culture conditions like dye concentration, temperature, pH, salinity, and additional nitrogen source were optimized in the present study. The optimal conditions for decolorization of reactive orange 16 was found to be: dye concentration 150mg/L, pH 7, temperature 35°C, and yeast extract as nitrogen source. The isolate was also resistant to 4% saline culture condition. Decolorization and degradation of dye were confirmed through UV-visible spectroscopy, Fourier transform infrared (FTIR) and liquid chromatography-mass spectrometry analysis (LC-MS). Toxicity studies were performed on Escherichiacoli and Vigna radiata to confirm the non-toxic nature of the degraded metabolites. This is the first study demonstrating complete decolorization of reactive orange 16 dye by Bacillus stratosphericus SCA1007 at high salinity within 10h of incubation under optimized conditions.