• Journal of Korean Society of Water and Wastewater
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• v.38 no.1
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• pp.17-27
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• 2024

This paper aims to study the degradation process for refractory azo dye namely Reactive Black 5(RB5) by potassium ferrate(VI) synthesized using the wet oxidation method. The process of degradation of azo dyes by Ferrate was studied with several parameters such as pH, different Ferrate(VI) dosage, different azo dye initial concentration, and temperature. A second-order reaction was observed in all degradation processes for RB5 having the highest degradation efficiency. The highest k_app value of RB5 degradation was 190.49 M^-1s^-1. In the pH experiments, the neutral condition has been identified as the optimum condition for the degradation of RB5 with 63.2% of dye removal. The efficiency of degradation also depends on the amount of ferrate(VI) available in the reactor. Degradation efficiency increased with an increase in Potassium Ferrate(VI) dosage or a decrease of RB5 initial concentration. The temperature has been reported as one of the most important parameters. From the results, increasing the temperature(up to 45℃) will increase the degradation efficiency of azo dye by Ferrate(VI) and if the temperature exceeds 45℃, the degradation efficiency will be decreased.

• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.198-203
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• 2012

Salting-out technique was adopted to crystallize dye crystals from dye solution. In this research solubility of dye solution and crystallization kinetics of Reactive dye (RB-8, RB-49, RR-218) was investigated. The empirical expressions of salting-out crystallization kinetics for Reactive dye (RB-8, RB-49, RR-218) in continuous MSMPR crystallizer was RB-8 in crystal growth kinetics $G=7.1{\times}10^{-4}{\Delta}C^{0.67}$ and nucleation kinetics $B^0=3.1{\times}10^{15}{\Delta}C[1.2{\times}10^{-8}+{\Delta}C^{0.7}M_T{^2}]$, RB-49 in crystal growth kinetics $G=5.2{\times}10^{-4}{\Delta}C^{0.3441}$ and nucleation kinetics $B^0=7.2{\times}10^{15}{\Delta}C[3.3{\times}10^{-8}+({\Delta}C)^{0.7}M_T{^2}]$, RR-218 in crystal growth kinetics $G=4.4{\times}10^{-4}{\Delta}C^{0.2361}$ and nucleation kinetics $B^0=6.3{\times}10^{15}{\Delta}C[7.9{\times}10^{-8}+({\Delta}C)^{0.7}M_T{^2}]$. Also, comparison of calculated crystal size distribution applying to characteristic curve method with experimental crystal size showed good agreement.

• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.110-114
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• 2010

The equilibrium of adsorption of basics dyes RB 5 and BG 4 from a single dyes in the mixtures on the sodium-exchanged clay of the Maghnia (Algeria) was studied. The maximum adsorption capacities of BR5 and BG4 in single dyes were 465.13 and 469.90 mg/g respectively. In the simultaneous adsorption of BR5 and BG4 from mixture solutions, three different initials concentrations ratios R (R=$C_{(BR5)}/C_{(BG4)}$) were tested: 2.5/1, 1/1 and 1/2.5 using ADMI method. The isotherms adsorptions of dyes from the mixtures are characteristics of competition phenomenon. A very strong interaction between BR5 and BG4 for the active sites of adsorption of surface of clay is obtained for R = 1/1. The ratio R' (R'=$Qe_{(mixture)}/Qe_{(single)}$) of the adsorption capacity of BR5 and BG4 in the mixture were reduced by factor of 0.86, 0.74 and 0.84 for the initials concentrations ratios R (R=$C_{(BR5)}/C_{(BG4)}$) of 2.5/1, 1/1 and 1/2.5 respectively. The variation of the ratio of the adsorption capacity R‘ of BR5 and BG4 in the mixture solutions with initial concentration ratios R indicates that BR5 dye is slightly favourable in the competition adsorption than BG4. Langmuir and Freundlich models fit very well with adsorption behaviour of single dyes as well as the dyes in mixture solutions.

• Journal of the Korean Wood Science and Technology
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• v.47 no.2
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• pp.163-177
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• 2019

This study aims to review the relations between the dyeing conditions (i.e., dye concentration, addition amounts of salt and alkali, and dyeing temperature) and dyeing properties and color fastness to light for identifying the optimal dyeing conditions when dyed regenerated woody fibers were obtained through the defibration of waste medium density fiberboard (MDF) using reactive Red H-E3B (Bis-monochlorotriazine (MCT)/MCT type) and reactive Red RB133% (Bis-MCT/Vinyl sulphone type). The dyeing yield (K/S) obtained using two types of reactive dyes increased as the dye concentration increased by 1-10% (on the weight of fiber (OWF)). In addition, the K/S of H-E3B was higher than that of RB133% irrespective of the dye concentration. The color difference of H-E3B after ultraviolet (UV) radiation was lower than that of RB133%, denoting good resistance to discoloration by UV. As the amount of sodium sulfate increased, the color difference and K/S also increased, and the adequate salt content was determined to be 50-70 g/L. Further, the color difference and K/S significantly increased only the addition of 2 g/L of sodium carbonate; however, almost no difference was observed when more than 2 g/L of sodium carbonate was added. The addition amount of sodium carbonate was adequate 5-10 g/L to dyeing the fiber and the pH at this addition level was 10. The dyeing yield of H-E3B increased when the dyeing temperature increased; however, it subsequently decreased after the dyeing temperature became $80^{\circ}C$. The dyeing yield of RB133% was almost the same up to $60-70^{\circ}C$ but declined subsequently. Thus, the adequate temperatures were $80^{\circ}C$ and $60^{\circ}C$ for H-E3B and RB133%, respectively. If the waste MDF woody fiber was dyed under the aforementioned optimal conditions, dyed regenerated woody fiber can be obtained having the following colors: 1.5 to 2.0R with the H-E3B dye and 9.6 to 10.0 PR with RB133%.

• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.115-119
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• 2010

Neutral red5 (BR 5) adsorption from aqueous solution was investigated. New solid adsorbent was prepared from paper sludge incinerated at $250^{\circ}C$ during 2 hours. Experiments were carried out, in batch system, to remove RB5 dye from the synthetic waste water. Maximum adsorption of 374.98 mg/g at pH 5, at room temperature and contact time of 80 min was obtained. The Langmuir and Freundlich adsorption models were applied to interpret the equilibrium isotherm. The Freundlich isotherm fits quite well with the experimental data (with highly regression coefficient $R^2$). The incinerated sludge solid samples untreated and treated with BR5 dye were characterized by FT-IR spectrophotometer.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.257-264
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• 2006

This study investigated the effects of hybrid process(chemical coagulation, Fenton oxidation and ceramic UF(ultrafiltration)) on COD and color removals of commercial reactive dyestuffs. In the case of chemical coagulation, the optimal concentrations of $Fe^{3+}$ coagulant for COD and color removals of RB49(reactive blue 49) and RY84(reactive yellow 84) were determined according to the different coagulant dose at the optimal pH. They were 2.78 mM(pH 7) in RB49 and 1.85 mM(pH 6) in RY84, respectively. In the case of Fenton oxidation, the optimal concentrations of $Fe^{3+}\;and\;H_2O_2$ were obtained. Optimal $[Fe^{2+}]:[H_2O_2]$ molar ratio of COD and color removals of RB49 and RY84 were 4.41:5.73 mM and 1.15:0.81 mM, respectively. In the case of ceramic UF, the flux and rejection of supernatant after Fenton oxidation were investigated. After ceramic UF for 9 hr, the average flux of RB49 and RY84 solutions were $53.4L/m^2hr\;and\;67.4L/m^2hr$ at 1 bar, respectively. In addition, the permeate flux increased and the average flux recovery were 98.5-99.9%(RB49) and 91.0-97.3%(RY84) according to adopting off-line cleaning(5% $H_2SO_4$). Finally, COD and color removals were 91.6-95.7% and 99.8% by hybrid process, respectively.

• Journal of the Korean GEO-environmental Society
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• v.12 no.11
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• pp.31-37
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• 2011

This study investigated on the adsorption and photocatalysis of Reactive Black 5(RB5) by the hydroxyapatite(HAP)/Titanium dioxide($TiO_{2}$) media. The adsorption of RB5 on $TiO_{2}$, HAP and $TiO_{2}$/HAP was investigated during a series of batch adsorption experiments. The amounts adsorbed at equilibrium were measured. Langmuir and Freundlich isotherm models were tested for their applicability. The result of equilibrium studies of $TiO_{2}$, HAP and $TiO_{2}$/HAP adsorbent were found to follow Langmuir isotherm model. The adsorbed amounts(Qmax) were found to be 5.28mg/g on single $TiO_{2}$, 12.45mg/g on single HAP and 9.03mg/g on $TiO_{2}$/HAP, respectively. The experimental data were analysed using the pseudo-first-order adsorption and photocatalysis kinetic models. According to these models, RB5 degradation by $TiO_{2}$/HAP was affected by interaction effect of photocatalysis and adsorption.

• Clean Technology
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• v.14 no.3
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• pp.211-217
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• 2008

We investigated the reduction of pollutants such as TOC (total organic carbon) and decolorization of Reactive Black 5 (RB5) by photocatalytic oxidation. The optimal values of major parameters for the reaction were obtained including the concentration of RB5, the amount of $TiO_2$ dosage and pH of solution. The values were 100 mg/L, 2 g/L and 4.9, respectively. As the concentration of oxygen increased, removal rate of pollutants increased. After $TiO_2$ was regenerated and used again by micro filtration (MF) ceramic membrane, the removal efficiency of color and removal rate of pollutants did not decrease significantly.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.259-267
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• 2010

The catalytic wet oxidations of the wastewater containing azo dye Reactive Black 5(RB5) with heterogeneous catalyst of CuO have been carried out to investigate the effects of temperature($190{\sim}230^{\circ}C$) and catalyst concentration(0.00~0.20 g/l) on the removals of colour and total organic carbon TOC. The wastewater colour was measured with spectrophotometer, and the oxidation rate was estimated with TOC. About 90% of colour was removed during 120 min in thermal degradation of the RB5 wastewater at $230^{\circ}C$, while TOC was not removed at all. As increasing reaction temperature and catalyst concentration, the removal rates of colour and TOC increased in the catalytic wet oxidations of RB5 wastewater. The effects of catalyst were already considerable even at 0.01 g CuO/l, while the removal rates of colour and TOC increased negligibly with increasing the catalyst concentration above 0.05 g CuO/l. The initial destruction rates of the wastewater colour have shown the first-order kinetics with respect to the wastewater colour. TOC changes during catalytic wet oxidations have been well described with the global model, in which the easily degradable TOC was distinguished from non-degradable TOC of the wastewater. The impacts of reaction temperature on the destruction rate of the wastewater colour and TOC could be described with Arrhenius relationship. Activation energies of the colour removal reaction in thermal degradation, wet oxidation, and catalytic wet oxidation(0.20 g CuO/l) of the RB5 wastewater were 108.4, 78.3 and 74.1 kJ/mol, respectively. The selectivity of wastewater TOC into the non-degradable intermediates relative to the end products in the catalytic wet oxidations of RB5 wastewater was higher compared to that in phenol wet oxidations.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.27-32
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• 2007

This study focused on estimating the feasibility of a strong basic anion exchanger (PA312OH) as a sorbent for the removal of residual reactive dye and saving chemicals and water. Cellulose reactive dye C.I.RB49 was tested because reactive dye is the largest single group of dyes and that dye needs larger amount of inorganic salts as dyeing agent but nearly 50% of reactive dyes may be lost to the effluent. The adsorption characteristics of PA312OH for C.I.RB49 were as follows. Ion-selectivity among the dye and inorganic salts was Dye > ${SO_4}^{2-}$ > ${CO_3}^{2-}$ > $Cl^-$. C.I.RB49 was exchanged more than 3 times ${SO_4}^{2-}$ and ${CO_3}^{2-}$ and $Cl^-$ was not exchanged absolutely. The exchanging velocity was increased exponentially with increasing temperature. This result is positive effect on treating the high temperature dyeing process wastewater. The exchanged dye percents to initial were 96.8% and 99% at flow rate 20.5 mL/min. and 3.7 mL/min.. The exchanging capacity of PA312OH for C.I.RB49 was 215.2 mg/g at conc.=369.2 mg/L, Temp.=$25^{\circ}C$. 74% inorganic salts were recrystallized from real dark reactive color dyeing wastewater treated with PA312OH.