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Zumriye Aksu - One of the best experts on this subject based on the ideXlab platform.
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potential use of cotton plant wastes for the removal of remazol black b Reactive Dye
Journal of Hazardous Materials, 2009Co-Authors: Ozlem Tunc, Hace Tanaci, Zumriye AksuAbstract:Abstract In this study, the potential use of cotton plant wastes – stalk (CS) and hull (CH) – as sorbents for the removal of Remazol Black B (RB5), a vinyl sulfone type Reactive Dye, was investigated. The results indicated that adsorption was strongly pH-dependent but slightly temperature-dependent for each sorbent-Dye system. The Freundlich, Langmuir, Redlich–Peterson and Langmuir–Freundlich adsorption models were used for the mathematical description of adsorption equilibrium and isotherm constants were evaluated at 25 °C. All models except the Freundlich model were applicable for the description of Dye adsorption by both sorbents in the concentration range studied. According to the Langmuir model, CS and CH sorbents exhibited the highest RB5 Dye uptake capacities of 35.7 and 50.9 mg g−1, respectively, at an initial pH value of 1.0. Simple mass transfer and kinetic models were applied to the experimental data to examine the mechanisms of adsorption and potential rate-controlling steps. It was found that both external mass transfer and intra-particle diffusion played an important role in the adsorption mechanisms of Dye, and adsorption kinetics followed the pseudo second-order type kinetic model for each sorbent. Using the Langmuir model parameters, thermodynamic constant ΔG° was also evaluated for each sorption system.
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continuous fixed bed biosorption of Reactive Dyes by dried rhizopus arrhizus determination of column capacity
Journal of Hazardous Materials, 2007Co-Authors: Zumriye Aksu, şeyda şen Cagatay, Ferda GonenAbstract:Abstract A continuous fixed bed study was carried out by using dried Rhizopus arrhizus as a biosorbent for the removal of three Reactive Dyes; Gemacion (Procion) Red H-E7B (GR), a monoclorotriazine mono-azo type Reactive Dye; Gemazol Turquise Blue-G (GTB), a vinyl sulfone mono-azo type Reactive Dye and Gemactive (Reactive) Black HFGR (GB), a vinyl sulfone di-azo type Reactive Dye from aqueous solution. The effect of operating parameters such as flow rate and inlet Dye concentration on the sorption characteristics of R. arrhizus was investigated at pH 2.0 and at 25 °C for each Dye. Data confirmed that the total amount of sorbed Dye decreased with increasing flow rate and increased with increasing inlet Dye concentration for each Dye. The column biosorption capacity of dried R. arrhizus was 1007.8 mg g−1 for GR Dye, 823.8 mg g−1 for GTB Dye and 635.7 mg g−1 for GB Dye at the highest inlet Dye concentration of approximately 750 mg l−1 and at the minimum flow rate of 0.8 ml min−1. Thomas and Yoon–Nelson models were applied to experimental data to predict the breakthrough curves and to determine the biosorption capacity of the column for each Dye useful for process design. Both models were found suitable for describing the whole dynamic behavior of the column with respect to flow rate and inlet Dye concentration.
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use of dried sugar beet pulp for binary biosorption of gemazol turquoise blue g Reactive Dye and copper ii ions equilibrium modeling
Chemical Engineering Journal, 2007Co-Authors: Zumriye Aksu, Alper I IsogluAbstract:In this study, simultaneous biosorption of Gemazol Turquoise Blue-G Reactive Dye anions and copper(II) cations to dried sugar beet pulp, an agricultural solid waste by-product, from binary mixtures was studied and compared with single Dye and metal ion situation in a batch stirred system. The effects of pH and single and dual component concentrations on the equilibrium uptake of each component, both singly and in mixture were investigated. The working pH value for the biosorption of single Gemazol Turquoise Blue-G Dye and single copper(II) was determined as 2.0 and 4.0, respectively. The equilibrium uptake of each component increased with increasing its initial concentration up to 750 mg l−1 for Dye and up to 200 mg l−1 for copper(II) ions for both pH values. The presence of increasing concentrations of copper(II) ions increased the equilibrium uptake of Dye anions while the adding of increasing concentrations of Dye diminished the copper(II) ion uptake for both pH values studied. This situation showed the synergistic effect of copper(II) cations on Dye biosorption and the antagonistic effect of Dye anions on copper(II) biosorption. Adsorption isotherms were developed for single-Dye, single copper(II) and dual-Dye-copper(II) ion systems at these two pH values and expressed by the mono-component Langmuir model and multi-component synergistic and antagonistic Langmuir models and model parameters were estimated by the non-linear regression.
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use of agricultural waste sugar beet pulp for the removal of gemazol turquoise blue g Reactive Dye from aqueous solution
Journal of Hazardous Materials, 2006Co-Authors: Zumriye Aksu, Alper I IsogluAbstract:Abstract The potential use of dried sugar beet pulp, an agricultural solid waste by-product, as an biosorbent for Gemazol turquoise blue-G, a copper–pthalocyanine Reactive Dye commonly used in Dyeing of cotton, was investigated in the present study. Batch adsorption studies were carried out to examine the influence of various parameters such as initial pH, temperature and initial Dye concentration. The results indicated that adsorption was strongly pH-dependent and slightly temperature-dependent. At 800 mg l−1 initial Gemazol turquoise blue-G concentration, dried sugar beet pulp exhibited the highest Gemazol turquoise blue-G uptake capacity of 234.8 mg g−1 at 25 °C and at an initial pH value of 2.0. The Freundlich, Langmuir, Redlich–Peterson and Langmuir–Freundlich, the two and three parameters adsorption models were used for the mathematical description of the biosorption equilibrium and isotherm constants were evaluated depending on temperature. Both the Langmuir and Redlich–Peterson models were applicable for describing the Dye biosorption by dried sugar beet pulp in the concentration (100–800 mg l−1) and temperature (25–45 °C) ranges studied. Simple mass transfer and kinetic models were applied to the experimental data to examine the mechanisms of biosorption and potential rate controlling steps such as external mass transfer, intraparticle diffusion and biosorption process. The sorption process was found to be controlled by both surface and pore diffusion with surface diffusion at the earlier stages followed by pore diffusion at the later stages. Pseudo first-order, pseudo second-order and saturation type kinetic models described the biosorption kinetics accurately at all concentrations and temperatures studied. The thermodynamic analysis indicated that the sorption process was exothermic and the biosorption of Dye on dried sugar beet pulp might be physical in nature.
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investigation of biosorption of gemazol turquise blue g Reactive Dye by dried rhizopus arrhizus in batch and continuous systems
Separation and Purification Technology, 2006Co-Authors: Zumriye Aksu, şeyda şen CagatayAbstract:Abstract Gemazol Turquise Blue-G, a vinyl sulfone mono-azo type Reactive Dye, containing copper-phtlalocyanine as cromofor group, was removed from its aqueous solution in batch and continuous packed bed sorption systems by using dried Rhizopus arrhizus as a biosorbent. Operating variables studied were temperature, initial pH, initial Dye concentration and sorbent dosage in the batch stirred system and flow rate and inlet Dye concentration in the continuous packed bed. In the batch system, the fungal biomass exhibited the highest Dye uptake as 773.0 mg g−1 at 45 °C, at an initial pH value of 2.0, at an initial Dye concentration of 812.6 mg l−1 for a biomass dosage of 0.5 g l−1. The Freundlich, Langmuir and Redlich–Peterson adsorption models were used for the mathematical description of the biosorption equilibrium and isotherm constants were evaluated at different temperatures. Equilibrium data fitted well the Langmuir model in the studied concentration (100–800 mg l−1) and temperature (25–45 °C) ranges. Sorption data were fitted to pseudo first-order, pseudo second-order and saturation type kinetic models assuming that the external mas transfer limitations in the system can be neglected. The Dye uptake process was found to follow pseudo second-order and saturation type kinetics. The thermodynamic parameters calculated showed that the adsorption process is feasible and has an endothermic character. The effect of operating parameters on the sorption characteristics of R. arrhizus in the continuous packed bed was investigated at pH 2.0 and at 25 °C. Data confirmed that the total amount of sorbed Dye and column sorption capacity decreased with increasing flow rate and increased with increasing inlet Dye concentration. The maximum column biosorption capacity of dried R. arrhizus cells was 823.8 mg g−1 at the highest inlet Dye concentration of 776.3 mg l−1 at the minimum flow rate of 0.8 ml min−1. Thomas model was applied to experimental column data to determine the characteristic parameters of column useful for process design and to predict the breakthrough curves. The model was found suitable for describing the whole part of dynamic behavior of the column with respect to flow rate and inlet Dye concentration.
Woranan Nakbanpote - One of the best experts on this subject based on the ideXlab platform.
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application of waste wood shaving bottom ash for adsorption of azo Reactive Dye
Journal of Environmental Management, 2009Co-Authors: Piyawan Leechart, Woranan Nakbanpote, Paitip ThiravetyanAbstract:The utilization of wood-shaving bottom ash (WBA) for the removal of Red Reactive 141 (RR141), an azo Reactive Dye, was investigated. WBA/H2O and WBA/H2SO4 were made by treating WBA with water and 0.1 M H2SO4, respectively, to increase adsorption capacity. Adsorption of RR141 from Reactive Dye solution (RDS) and Reactive Dye wastewater (RDW) by WBA/H2O and WBA/H2SO4 involved the BET surface area and pore size diameter. Properties of adsorbents, effect of contact time, initial pH of solution, dissolved metals and elution studies indicated that the decolorisation mechanism involved both chemical adsorption and precipitation with calcium ions. In addition, the WBA/H2SO4 surface might contain sulphate–cation complexes that were specific to enhancing Dye adsorption from RDW. The adsorption isotherm had a best fit by the Freundlich model. Freundlich parameters showed that WBA/H2O used more heterogeneous surface than WBA/H2SO4 and activated carbon for RDW adsorption. A thermodynamic study indicated that RDW adsorption was an endothermic process. The maximum Dye adsorption capacities of WBA/H2O, WBA/H2SO4 and activated carbon obtained from a Langmuir model at 30
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synthetic Reactive Dye wastewater treatment by narrow leaved cattails typha angustifolia linn effects of Dye salinity and metals
Science of The Total Environment, 2007Co-Authors: S Nilratnisakorn, Paitip Thiravetyan, Woranan NakbanpoteAbstract:Abstract Narrow-leaved cattails were studied in synthetic Reactive Dye wastewater (SRDW) under caustic conditions. The effects of the toxic Dye were expressed in terms of relative plant growth rate and the appearance of symptoms such as necrosis, and chronic or acute wilting. The Dye toxicity was 25.33 mg l −1 which was close to approximate the concentration of Dye residue from the textile effluent in the public stream. The system pH and % color removal were decreased, indicating that narrow-leaved cattail can treat wastewater. The average system pH decreased from 9 to 7. The maximum color removal was approximately 60% when cultured under soil conditions. The SEM image of narrow-leaved cattail root after treatment with SRDW indicated that the root cortex was damaged and the crystalline sodium salts deposited in the root cells which caused evaporation and transpiration decreased in SRDW. The salinity under caustic conditions also affects the growth of the plants. The maximum sodium removal was approximately 44% and was found in the SRDW under soil conditions within 14 days. A small amount of sodium could enhance the relative growth rate. However, the sodium removal of the plants was limited after the third week of treatment. It should be noted that narrow-leaved cattails are known to avoid the textile Dye and salt stress conditions during SRDW treatment through special mechanisms such as salt accumulation in the roots or shedding of older leaves. In addition, elements such as silicon, calcium and iron in plants might help the plant to detoxify by forming complexes with Dye molecules.
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adsorption mechanism of synthetic Reactive Dye wastewater by chitosan
Journal of Colloid and Interface Science, 2005Co-Authors: Niramol Sakkayawong, Paitip Thiravetyan, Woranan NakbanpoteAbstract:Abstract Chitosan was able to remove the color from synthetic Reactive Dye wastewater (SRDW) under acidic and caustic conditions. The effect of the initial pH on SRDW indicated that electrostatic interaction occurred between the effective functional groups (amino groups) and the Dye under acidic conditions. Moreover, SRDW adsorption under caustic conditions was also affected by the covalent bonding of Dye and hydroxyl groups of chitosan. In addition, elution tests confirmed that chemical adsorption occurred under acidic conditions, while both physical and chemical adsorption appeared under caustic conditions. The spectra of attenuated total reflectance Fourier transform infrared spectrometry confirmed the functional groups of chitosan that affected the SRDW adsorption. However, the maximum adsorption capacities of chitosan increased when the temperature increased. The maximum adsorption capacity of chitosan obtained from the Langmuir model was 68, 110, and 156 mg g−1 under a system pH of 11.0 at 20, 40, and 60 °C, respectively. The negative values of enthalpy change (ΔH), free energy change (ΔG), and entropy change (ΔS) indicated an exothermic, spontaneous process and decreasing disorder of the system, respectively. Therefore, the mechanism of SRDW adsorption by chitosan was probably by chemical adsorption for a wide range of pH's and at high temperatures.
Gonul Donmez - One of the best experts on this subject based on the ideXlab platform.
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potential of gonium spp in synthetic Reactive Dye removal possible role of laccases and stimulation by triacontanol hormone
Water Air and Soil Pollution, 2011Co-Authors: Nur Kocberber Kilic, Ergin Duygu, Sevgi Ertugrul Karatay, Gonul DonmezAbstract:In this study, Gonium sp. was investigated for possible usage in Dye-containing wastewater treatment. Trials were performed in media including triacontanol hormone, Reactive Orange 14, Reactive Red 120, Reactive Black 5, Remazol Brilliant Blue R (RBBR), and also hormone against the controls. Algae could remove RBBR with the highest Dye removal percentage (56%) among the tested Dyes. The optimum pH was 9 in removing 50 mg L−1 RBBR at a Dye removal percentage of 47.1%. The role of laccase activity of Gonium sp. was also investigated. This first attempt in the literature showed the involvement of the enzyme in the algal growth and bioremoval process. In the presence of the plant growth hormone in the culture, the activity showed a steady and significant increase up to nearly sixfold between 5th and 14th days of incubation.
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effective bioremoval of Reactive Dye and heavy metals by aspergillus versicolor
Bioresource Technology, 2010Co-Authors: Urcu Erti Tasta, Sevgi Ertugrul, Gonul DonmezAbstract:In this study, bioaccumulation of heavy metal and Dye by Aspergillus versicolor was investigated. Optimum pH values of the maximum heavy metal bioaccumulation was found as 6 for 50mg/L Cr(VI), Ni(II) and 5 for Cu(II) ions with the 99.89%, 30.05% and 29.06% removal yield, respectively. The bioremoval of the Dye up to 800 mg/L at pH 5 and 6 was investigated and 27.15% and 28.95% removal rates were measured respectively. The presence of Cr(VI) with Dye, decreased the uptake yield for both pollutants. In the medium with Cu(II) and Dye, Dye removal was not affected by Cu(II), but Cu(II) removal rate increased from 29.06% to 37.91% by the existence of the Dye. When Ni(II) and Dye were combined, neither pollutant affected the other's removal yield. These results indicate that the isolated A. versicolor strain deserves attention as a promising bioaccumulator of heavy metal ions and Reactive Dyes in wastewater effluents.
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stimulation of Reactive Dye removal by cyanobacteria in media containing triacontanol hormone
Journal of Hazardous Materials, 2009Co-Authors: Pinar Karacakaya, Nur Kocberber Kilic, Ergin Duygu, Gonul DonmezAbstract:In this study, Reactive Red, Remazol Blue, and Reactive Black B removal capacities of Synechocystis sp. and Phormidium sp. were investigated. The microorganisms were cultivated in 100 ml BG 11 medium and incubated at 30 ◦ C under continuous illumination (12.5 w m −2 (2400 lx)) for 20 days in plant growth chamber. Trials were carried out at pH 9.5 for Reactive Red, pH 8.5 for Remazol Blue and Reactive Black B removal in media without and with triacontanol (TRIA). Removal capacities of Synechocystis sp. and Phormidium sp. were found higher in media containing TRIA. So that, Synechocystis sp. and Phormidium sp. removed Reactive Red with 25.7% and 35.4%, Remazol Blue with 37.5% and 25.5%, and Reactive Black B with 29.2% and 28.3% yield at 25 mg l −1 Dye concentrations, respectively. There is no report investigating Dye removal by Synechocystis sp. and removal of pollutants in media including TRIA hormone. Our data indicated the cyanobacteria tested in this study were suitable for effective treatment processes of such wastewaters including Reactive Dyes, and their removal capacity could be increased by TRIA, through stimulation of the biomass production.
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a comparative study on the biosorption characteristics of some yeasts for remazol blue Reactive Dye
Chemosphere, 2003Co-Authors: Zumriye Aksu, Gonul DonmezAbstract:Abstract Biosorption capacities and rates of different kinds of dried yeasts ( Saccharomyces cerevisiae , Schizosaccharomyces pombe , Kluyveromyces marxianus , Candida sp., C. tropicalis , C. lipolytica , C. utilis , C. quilliermendii and C. membranaefaciens ) for Remazol Blue Reactive Dye from aqueous solutions were compared under laboratory conditions as a function of initial pH and initial Dye concentration. Optimum initial biosorption pH was determined as 2 for all the yeasts. All the yeast species showed comparable and very high Dye sorption at 100 mg/l initial Dye concentration. The equilibrium sorption capacity of the biomass increased with increasing initial Dye concentration up to 400 mg/l for Candida sp. C. lipolytica and C. tropicalis ; up to 300 mg/l for C. quilliermendii and C. utilis and up to 200 mg/l for S. cerevisiae , S. pombe , K. marxianus and C. membranaefaciens while the adsorption yield of Dye showed the opposite trend for all the yeasts. Among the nine yeast species, C. lipolytica exhibited the highest Dye uptake capacity ( Q 0 =250 mg/g). Both the Freundlich and Langmuir adsorption models were found suitable for describing the biosorption of the Dye by all the Candida yeasts (except C. membranaefaciens ). The results indicated that the Dye uptake process followed the pseudo-second-order kinetics for each Dye–yeast system.
Paitip Thiravetyan - One of the best experts on this subject based on the ideXlab platform.
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application of waste wood shaving bottom ash for adsorption of azo Reactive Dye
Journal of Environmental Management, 2009Co-Authors: Piyawan Leechart, Woranan Nakbanpote, Paitip ThiravetyanAbstract:The utilization of wood-shaving bottom ash (WBA) for the removal of Red Reactive 141 (RR141), an azo Reactive Dye, was investigated. WBA/H2O and WBA/H2SO4 were made by treating WBA with water and 0.1 M H2SO4, respectively, to increase adsorption capacity. Adsorption of RR141 from Reactive Dye solution (RDS) and Reactive Dye wastewater (RDW) by WBA/H2O and WBA/H2SO4 involved the BET surface area and pore size diameter. Properties of adsorbents, effect of contact time, initial pH of solution, dissolved metals and elution studies indicated that the decolorisation mechanism involved both chemical adsorption and precipitation with calcium ions. In addition, the WBA/H2SO4 surface might contain sulphate–cation complexes that were specific to enhancing Dye adsorption from RDW. The adsorption isotherm had a best fit by the Freundlich model. Freundlich parameters showed that WBA/H2O used more heterogeneous surface than WBA/H2SO4 and activated carbon for RDW adsorption. A thermodynamic study indicated that RDW adsorption was an endothermic process. The maximum Dye adsorption capacities of WBA/H2O, WBA/H2SO4 and activated carbon obtained from a Langmuir model at 30
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synthetic Reactive Dye wastewater treatment by narrow leaved cattails typha angustifolia linn effects of Dye salinity and metals
Science of The Total Environment, 2007Co-Authors: S Nilratnisakorn, Paitip Thiravetyan, Woranan NakbanpoteAbstract:Abstract Narrow-leaved cattails were studied in synthetic Reactive Dye wastewater (SRDW) under caustic conditions. The effects of the toxic Dye were expressed in terms of relative plant growth rate and the appearance of symptoms such as necrosis, and chronic or acute wilting. The Dye toxicity was 25.33 mg l −1 which was close to approximate the concentration of Dye residue from the textile effluent in the public stream. The system pH and % color removal were decreased, indicating that narrow-leaved cattail can treat wastewater. The average system pH decreased from 9 to 7. The maximum color removal was approximately 60% when cultured under soil conditions. The SEM image of narrow-leaved cattail root after treatment with SRDW indicated that the root cortex was damaged and the crystalline sodium salts deposited in the root cells which caused evaporation and transpiration decreased in SRDW. The salinity under caustic conditions also affects the growth of the plants. The maximum sodium removal was approximately 44% and was found in the SRDW under soil conditions within 14 days. A small amount of sodium could enhance the relative growth rate. However, the sodium removal of the plants was limited after the third week of treatment. It should be noted that narrow-leaved cattails are known to avoid the textile Dye and salt stress conditions during SRDW treatment through special mechanisms such as salt accumulation in the roots or shedding of older leaves. In addition, elements such as silicon, calcium and iron in plants might help the plant to detoxify by forming complexes with Dye molecules.
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adsorption mechanism of synthetic Reactive Dye wastewater by chitosan
Journal of Colloid and Interface Science, 2005Co-Authors: Niramol Sakkayawong, Paitip Thiravetyan, Woranan NakbanpoteAbstract:Abstract Chitosan was able to remove the color from synthetic Reactive Dye wastewater (SRDW) under acidic and caustic conditions. The effect of the initial pH on SRDW indicated that electrostatic interaction occurred between the effective functional groups (amino groups) and the Dye under acidic conditions. Moreover, SRDW adsorption under caustic conditions was also affected by the covalent bonding of Dye and hydroxyl groups of chitosan. In addition, elution tests confirmed that chemical adsorption occurred under acidic conditions, while both physical and chemical adsorption appeared under caustic conditions. The spectra of attenuated total reflectance Fourier transform infrared spectrometry confirmed the functional groups of chitosan that affected the SRDW adsorption. However, the maximum adsorption capacities of chitosan increased when the temperature increased. The maximum adsorption capacity of chitosan obtained from the Langmuir model was 68, 110, and 156 mg g−1 under a system pH of 11.0 at 20, 40, and 60 °C, respectively. The negative values of enthalpy change (ΔH), free energy change (ΔG), and entropy change (ΔS) indicated an exothermic, spontaneous process and decreasing disorder of the system, respectively. Therefore, the mechanism of SRDW adsorption by chitosan was probably by chemical adsorption for a wide range of pH's and at high temperatures.
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decolorization of basic direct and Reactive Dyes by pre treated narrow leaved cattail typha angustifolia linn
Bioresource Technology, 2004Co-Authors: Duangrat Inthorn, Paitip Thiravetyan, Siritham Singhtho, Eakalak KhanAbstract:The efficiency of basic, direct and Reactive Dye removal from water by narrow-leaved cattail (NLC) powder treated with distilled water (DW-NLC), 37% formaldehyde + 0.2 N sulfuric acid (FH-NLC), or 0.1 N sodium hydroxide (NaOH-NLC) at various pH levels (3, 5, 7, and 9) was tested. Desorption of the adsorbed Dyes was also investigated. The type of NLC treatment and pH of the Dye solution had little effect on removal of basic Dyes, and efficiencies ranged from 97% to 99% over the range of pH used. Over a wide range of pH levels, all types of treated cattail powder had negative charges and probably attracted the basic Dyes possessing positive charges. Efficiency of removal by the three NLC treatments ranged from 37% to 42% for direct Dyes and from 22% to 54% for direct Dyes at pH 7. The pH of the Dye solution had substantial effects on the efficiency of removal in direct and Reactive Dyes. Dye removal was highest at pH 3, with 99% for a direct Dye (Sirius Red Violet RL) and 96% for a Reactive Dye (Basilen Red M-5B). There was mutual attraction between negatively charged direct Dye molecules and positively charged molecules on the surface of the FH-treated cattail. In tests of desorption of Dyes from cattail in distilled water, the desorption percentage for FH-NLC after adsorbing basic, direct and Reactive Dyes was 6%, 10% and 35%, respectively, which indicated a chemisorption mechanism for basic and direct Dyes and some physiosorption for Reactive Dyes.
Alenka Majcen Le Marechal - One of the best experts on this subject based on the ideXlab platform.
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case study of the sonochemical decolouration of textile azo Dye Reactive black 5
Journal of Hazardous Materials, 2007Co-Authors: Simona Vajnhandl, Alenka Majcen Le MarechalAbstract:Abstract The decolouration and mineralization of Reactive Dye C.I. Reactive Black 5, a well-known representative of non-biodegradable azo Dyes, by means of ultrasonic irradiation at 20, 279 and 817 kHz has been investigated with emphasis on the effect of various parameters on decolouration and degradation efficiency. Characterization of the used ultrasound systems was performed using calorimetric measurements and oxidative species monitoring using Fricke and iodine dosimeter. Experiments were carried out with low frequency probe type, and a high-frequency plate type transducer at 50, 100 and 150 W of acoustic power and within the 5–300 mg/L initial Dye concentration range. Decolouration, as well as radical production, increased with increasing frequency, acoustic power, and irradiation time. Any increase in initial Dye concentration results in decreased decolouration rates. Sonochemical decolouration was substantially depressed by the addition of 2-methyl-2-propanol as a radical scavenger, which suggests radical-induced reactions in the solution. Acute toxicity to marine bacteria Vibrio fischeri was tested before and after ultrasound irradiation. Under the conditions employed in this study, no toxic compounds were detected after 6 h of irradiation. Mineralization of the Dye was followed by TOC measurements. Relatively low degradation efficiency (50% after 6 h of treatment) indicates that ultrasound is rather inefficient in overall degradation, when used alone.
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case study of the sonochemical decolouration of textile azo Dye Reactive black 5
Journal of Hazardous Materials, 2007Co-Authors: Simona Vajnhandl, Alenka Majcen Le MarechalAbstract:Abstract The decolouration and mineralization of Reactive Dye C.I. Reactive Black 5, a well-known representative of non-biodegradable azo Dyes, by means of ultrasonic irradiation at 20, 279 and 817 kHz has been investigated with emphasis on the effect of various parameters on decolouration and degradation efficiency. Characterization of the used ultrasound systems was performed using calorimetric measurements and oxidative species monitoring using Fricke and iodine dosimeter. Experiments were carried out with low frequency probe type, and a high-frequency plate type transducer at 50, 100 and 150 W of acoustic power and within the 5–300 mg/L initial Dye concentration range. Decolouration, as well as radical production, increased with increasing frequency, acoustic power, and irradiation time. Any increase in initial Dye concentration results in decreased decolouration rates. Sonochemical decolouration was substantially depressed by the addition of 2-methyl-2-propanol as a radical scavenger, which suggests radical-induced reactions in the solution. Acute toxicity to marine bacteria Vibrio fischeri was tested before and after ultrasound irradiation. Under the conditions employed in this study, no toxic compounds were detected after 6 h of irradiation. Mineralization of the Dye was followed by TOC measurements. Relatively low degradation efficiency (50% after 6 h of treatment) indicates that ultrasound is rather inefficient in overall degradation, when used alone.
