Sangyong Kim | Korea Institute of Industrial Technology (original) (raw)

Papers by Sangyong Kim

Research paper thumbnail of Improved high-pressure enzymatic biodiesel batch synthesis in near-critical carbon dioxide

The enzymatic synthesis of biodiesel by a highpressure semi-continuous process in near-critical c... more The enzymatic synthesis of biodiesel by a highpressure semi-continuous process in near-critical carbon dioxide (NcCO 2 ) was studied. Biodiesel synthesis was evaluated in both batch and semi-continuous systems to develop an effective process. Batch processing demonstrated the advantageous properties of NcCO 2 as an alternative reaction medium. Three immobilized lipases (Novozym 435, Lipozyme RM IM, and Lipozyme TL IM from Novozymes) were tested, with Lipozyme TL IM the most effective, showing the highest conversion. Biodiesel conversion from several edible and non-edible oil feedstocks reached [92%. Higher conversion (99.0%) was obtained in a shorter time by employing repeated batch processes with optimized conditions: 44.3 g (500 mM) canola oil, a substrate molar ratio (methanol:oil) of 3:1, an enzyme loading of 20 wt% (of the oil used), at 30°C, 100 bar, and 300 rpm agitation. The enzyme maintained 80.2% of its initial stability after being reused eight times. These results suggest that this method produces biodiesel energy-efficiently and environment-friendly.

Research paper thumbnail of Hydrogen production from biodiesel byproduct by immobilized Enterobacter aerogenes

The recent rapid growth of the biodiesel industry has generated a significant amount of glycerol ... more The recent rapid growth of the biodiesel industry has generated a significant amount of glycerol as a byproduct. As a result, the price of glycerol is currently relatively low, making it an attractive starting material for the production of chemicals with higher values. Crude glycerol can be directly converted through microbial fermentation into various chemicals such as hydrogen. In this study, we optimized immobilization of a facultative hydrogen producing microorganism, Enterobacter aerogenes, with the goal of developing biocatalysts that was appropriate for the continuous hydrogen production from glycerol. Several carriers were tested and agar was found to be the most effective. In addition, it was clearly shown that variables such as the carrier content and cell loading should be controlled for the immobilization of biocatalysts with high hydrogen productivity, stability, and reusability. After optimization of these variables, we were able to obtain reusable biocatalysts that could directly convert the byproduct stream from biodiesel processes into hydrogen in continuous processes.

Research paper thumbnail of Pilot scale treatment of textile wastewater by combined process (fluidized biofilm process–chemical coagulation–electrochemical oxidation)

Water Research, 2002

The performance of pilot scale combined process of fluidized biofilm process, chemical coagulatio... more The performance of pilot scale combined process of fluidized biofilm process, chemical coagulation and electrochemical oxidation for textile wastewater treatment was studied. In order to enhance biological treatment efficiency, two species of microbes, which can degrade textile wastewater pollutants efficiently, were isolated and applied to the system with supporting media. FeCl 3 Á 6H 2 O, pH 6 and 3.25 Â 10 À3 mol/l were determined as optimal chemical coagulation condition and 25 mM NaCl of electrolyte concentration, 2.1 mA/cm 2 of current density and 0.7 l/ min of flow rate were chosen for the most efficient electrochemical oxidation at pilot scale treatment. The fluidized biofilm process showed 68.8% of chemical oxygen demand (COD) and 54.5% of color removal efficiency, even though using relatively low MLSS concentration and short sludge retention time. COD and color removals of 95.4% and 98.5% were achieved by overall combined process. The contribution of fluidized biofilm process to the overall combined process was increased over 25.7% of COD reduction and 20.5% of color reduction by adopting support media in biological treatment. It can be thought that the fluidized biofilm process was effective, and pollutant loading on post-treatment was pretty much decreased by this system. This combined process was highly competitive in comparison to the other similar combined systems. It was concluded that this combined process was successfully employed and much effectively decreased pollutant loading on post-treatment for textile wastewater treatment at pilot scale. r

Research paper thumbnail of COD reduction and decolorization of textile effluent using a combined process

Journal of Bioscience and Bioengineering, 2003

This study showed the effectiveness of biological pretreatment involving appropriate microorganis... more This study showed the effectiveness of biological pretreatment involving appropriate microorganisms and suitable support media in a combined process. The combined process consists of biological pretreatment, chemical coagulation and electrochemical oxidation. COD and color were reduced by 95.4% and 98.5% by the combined process, respectively.

Research paper thumbnail of Upgrading of anaerobic digestion by incorporating two different hydrolysis processes

Journal of Bioscience and Bioengineering, 2005

The purpose of this study was to increase the efficiency of anaerobic digestion of waste activate... more The purpose of this study was to increase the efficiency of anaerobic digestion of waste activated sludge (WAS). Either thermochemical or biological hydrolysis was used as a pretreatment and the effects of both were investigated and compared. Two different three-stage digestion systems showed improved performance, although thermochemical hydrolysis showed better results than biological hydrolysis in a bench-scale operation. After anaerobic digestion with thermochemical pretreatment, the total chemical oxygen demand (tCOD) reduction, volatile solid (VS) reduction, methane yield and methane biogas content were 88.9%, 77.5%, 0.52 m 3 /kg VS and 79.5%, respectively. These results should help in determining the best hydrolysis pretreatment process for anaerobic digestion and in improving the design and operation of the large-scale treatment of WAS by anaerobic digestion with hydrolysis systems.

Research paper thumbnail of Biokinetic Parameter Estimation for Degradation of 2,4,6-Trinitrotoluene (TNT) with Pseudomonas putida KP-T201

Journal of Bioscience and Bioengineering, 2002

The purpose of this study is to determine the biodegradation kinetics of 2,4,6-trinitrotoluene (T... more The purpose of this study is to determine the biodegradation kinetics of 2,4,6-trinitrotoluene (TNT) by a newly isolated microorganism.

Research paper thumbnail of Bioremediation of 2,4,6-Trinitrotoluene Contaminated Soil in Slurry and Column Reactors

Journal of Bioscience and Bioengineering, 2003

Two composting systems were compared on a laboratory scale as a bioremediation technology for deg... more Two composting systems were compared on a laboratory scale as a bioremediation technology for degradation or immobilization of 2,4,6-trinitrotoluene (TNT) in contaminated soils. The first compost was aerated from the beginning whereas the second compost was only aerated after an anaerobic prephase of 65 days. In the first compost system the TNT concentration declined rapidly by 92% but, at the end, TNT could be partially recovered. During the anaerobic prephase of the second compost system, TNT was almost completely converted to aminodinitrotoluenes, which during the subsequent aeration almost entirely disappeared. In addition, the second compost generated less toxic material than the first one as confirmed by inhibition of bioluminescence of Vibrio fischeri.

Research paper thumbnail of Optimization for Biodegradation of 2,4,6-Trinitrotoluene (TNT) by Pseudomonas putida

Journal of Bioscience and Bioengineering, 2003

In this study, a strain of Pseudomonas putida KP-T202, isolated from the soil in a contaminated s... more In this study, a strain of Pseudomonas putida KP-T202, isolated from the soil in a contaminated site, degraded 2,4,6-trinitrotoluene (TNT). In order to make this biodegradation process commercially feasible and reduce biodegradation time, optimal environmental factors are determined. At an initial concentration of 100 mg/l, TNT was totally degraded within 15 h under aerobic conditions. The optimal conditions for the biodegradation of TNT were found to be 30 degrees C, pH 7, 1% corn steep liquor (CSL), 0.025% NH,CI and 0.1% Tween 80; the reaction rate constant was 0.348 h(-1) These environmental conditions can be used to improve the efficiency of large-scale reactors for the treatment of TNT-contaminated wastewater and soil. In addition, the intermediates were identified as 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene, 2,4-dinitrotoluene and 2,6-dinitrotoluene.

Research paper thumbnail of COD Reduction and Decolorization of Textile Effluent Using a Combined Process

Journal of Bioscience and Bioengineering, 2003

This study showed the effectiveness of biological pretreatment involving appropriate microorganis... more This study showed the effectiveness of biological pretreatment involving appropriate microorganisms and suitable support media in a combined process. The combined process consists of biological pretreatment, chemical coagulation and electrochemical oxidation. COD and color were reduced by 95.4% and 98.5% by the combined process, respectively.

Research paper thumbnail of Synthesis of carbohydrate biomass-based furanic compounds bearing epoxide end group(s) and evaluation of their feasibility as adhesives

Journal of Adhesion Science and Technology, 2013

Current issues of energy and environment prompt us to replace fossil-based resources with renewab... more Current issues of energy and environment prompt us to replace fossil-based resources with renewable and sustainable ones. In this regard, carbohydrate biomass photosynthesized from atmospheric carbon dioxide attracts much attention due to its abundance and availability. Recently, furanic compounds that can be derived from carbohydrate biomass are highlighted as promising substitutes for aromatic compounds that are totally dependent on petroleum

Research paper thumbnail of Optimization and morphology for decolorization of reactive black 5 by Funalia trogii

Enzyme and Microbial Technology, 2007

The influence of the various carbon and nitrogen sources on the decolorization of reactive black ... more The influence of the various carbon and nitrogen sources on the decolorization of reactive black 5 (RB 5) by Funalia trogii was examined using a classical method of medium optimization. Of the carbon sources examined as effective co-substrates, fructose, glycerol, and starch were found to be satisfactory, whereas lactose and sucrose were not. When ammonium tartrate, yeast extract, and peptone were used as nitrogen sources, the decolorization rate was high. An optimal pH is important for fungal growth, and our system operated best at a pH 5-6. By combining a Latin square design with a classical method of medium optimization, the essential medium components were identified using liquid culture experiments. Morphological changes of F. trogii were found to be significantly related to decolorization, and changes in fractal dimension followed RB 5-decolorizing enzyme activity.

Research paper thumbnail of Decolorization of acid black 52 by fungal immobilization

Enzyme and Microbial Technology, 2006

In order to achieve an effective decolorization with Funalia trogii, fungal immobilization and re... more In order to achieve an effective decolorization with Funalia trogii, fungal immobilization and repeated batch experiment were investigated. The activities of three enzymes, namely laccase, lignin peroxidase (LiP) and manganese peroxidase (MnP), were reported during decolorization of acid black 52 under the condition of immobilized and suspended fungal mycelia. When F. trogii were immobilized in Na-alginate, the cell viability increased as alginate concentration was increased, although the cell concentration decreased. Na-alginate of 4% (w/v) was an optimum concentration. Decolorization rate by fungal immobilization was higher than that by suspended cultivation. Decolorization could be stably maintained with the repeated batch experiments during long period (at least for 300 h).

Research paper thumbnail of Optimization of backflushing conditions for ceramic ultrafiltration membrane of disperse dye solutions

Desalination, 2007

ABSTRACT

Research paper thumbnail of Decolorization of disperse and reactive dye solutions using ferric chloride

Desalination, 2004

The composition of wastewater from dyeing and textile processes is highly variable depending on t... more The composition of wastewater from dyeing and textile processes is highly variable depending on the dyestuff type; typically it has a high chemical oxygen demand. This study examined the decolorization of some of the most commonly used disperse and reactive ...

Research paper thumbnail of Electrochemical oxidation of polyvinyl alcohol using a RuO2/Ti anode

Desalination, 2003

Polyvinyl alcohol (PVA), known as the dominant contributor of chemical oxygen demand (COD) in tex... more Polyvinyl alcohol (PVA), known as the dominant contributor of chemical oxygen demand (COD) in textile wastewater, is very difficult to decompose by conventional treatment technologies. In this study, electrochemical oxidation using a RuO/Ti anode was applied to treat a PVA solution. The mechanisms of PVA degradation and COD destruction were investigated, while the operating parameters affecting the mechanisms were also studied. The parameters investigated included current density, PVA concentration in waste stream, the rate of electrolyte consumption of sodium chloride, and the feed rate of wastewater. The overall mass transport behavior of electrochemical oxidation of PVA was explained by the mathematical relationship of dimensionless numbers such as the Reynolds, Schmidt and Sherwood numbers.

Research paper thumbnail of Decolorization of disperse and reactive dyes by continuous electrocoagulation process

Desalination, 2002

The electrocoagulation process was developed to overcome the drawbacks of conventional wastewater... more The electrocoagulation process was developed to overcome the drawbacks of conventional wastewater treatment technologies. This process is very effective in removing organic pollutants including dyestuffwastewater and allows for the reduction of sludge generation. The purposes of this study were to investigate the effects of the operating parameters, such as current density, electrode number, electrolyte concentration, electrode gap, dyestuff concentration, pH of solution and inlet flow rate, on decoiorization by continuous electrocoagulation. The dye removal efficiencies and reaction rate constants from the curves following the first-order relationship ofelectrocoagulation were calculated. In addition, from the points of power consumption, the effects of the operating parameters were also searched. Finally, the behaviors of decolorization according to dyestuff types, i.e., disperse dye and reactive dye, were also examined.

Research paper thumbnail of Decolorization of dye solutions by a membrane bioreactor (MBR) using white-rot fungi

Desalination, 2004

In this study a membrane bioreactor (MBR) using white-rot fungi was used for the decolorization o... more In this study a membrane bioreactor (MBR) using white-rot fungi was used for the decolorization of dye solutions. The decolorization of dye solutions by Trametes versicolor KCTC 16781 and membrane filtration were combined, and the applicability of this process was investigated ...

Research paper thumbnail of Facile Single-Step Conversion of Macroalgal Polymeric Carbohydrates into Biofuels

ChemSusChem, 2010

ABSTRACT Red macroalgae-derived agar is a renewable and sustainable resource. For the synthesis o... more ABSTRACT Red macroalgae-derived agar is a renewable and sustainable resource. For the synthesis of HMF under solid Brønsted acid conditions, agar shows a unique reaction pattern and affords higher yields than land plant-based polymeric carbohydrates. Agar can be directly converted into next-generation biofuels by one-pot reactions and readily isolated by using a general workup procedure, which is crucial for a large-scale process.

Research paper thumbnail of Strain development and medium optimization for fumaric acid production

Biotechnology and Bioprocess Engineering, 2010

Rhizopus oryzae RUR709 mutant was isolated based on halo size from selection medium via mutagenes... more Rhizopus oryzae RUR709 mutant was isolated based on halo size from selection medium via mutagenesis with UV and γ-rays, and the production of fumaric acid in the submerged fermentation was assessed. The maximum concentration of fumaric acid was obtained using 0.5% corn steep liquor (CSL) as the nitrogen source. Organic nitrogen sources were shown to be more effective in fumaric acid production than inorganic nitrogen sources. Using optimum medium obtained by response surface methodology (RSM), the maximum concentration of fumaric acid achieved in flask culture was 26.2 g/L, which is fairly close to the 27.4 g/L predicted by the model. The highest concentration of fumaric acid in the stirred-tank reactor generated by the R. oryzae RUR709 mutant was 32.1 g/L and yield (0.45 g/g) and productivity (0.32 g/L/h) were highest at 4 days.

Research paper thumbnail of Biodegradation and biosorption for decolorization of synthetic dyes by Funalia trogii

Biochemical Engineering Journal, 2007

The objective of this study was to investigate two major mechanisms for decolorization of dyes by... more The objective of this study was to investigate two major mechanisms for decolorization of dyes by cultivation of fungi on either a solid or in a liquid phase and to confirm the possibility of practical application via repeated-batch cultivation. The decolorization of six commercial dyes with 10 fungal strains was studied. Enzyme activity, decolorization trends and decolorization mechanisms were monitored. Under the experimental conditions, extracellular laccase and manganese peroxidase (MnP), but not lignin peroxidase (LiP), were detected. The decolorization mechanisms by F. trogii ATCC 200800 involved a complex interaction of enzyme activity and biosorption. This study suggests that it is possible to decolorize a high concentration of commercial dyes, which would be a great advance in the treatment of dye containing wastewater. These methods may have a potential application for dye decolorization and for textile effluent treatment.

Research paper thumbnail of Improved high-pressure enzymatic biodiesel batch synthesis in near-critical carbon dioxide

The enzymatic synthesis of biodiesel by a highpressure semi-continuous process in near-critical c... more The enzymatic synthesis of biodiesel by a highpressure semi-continuous process in near-critical carbon dioxide (NcCO 2 ) was studied. Biodiesel synthesis was evaluated in both batch and semi-continuous systems to develop an effective process. Batch processing demonstrated the advantageous properties of NcCO 2 as an alternative reaction medium. Three immobilized lipases (Novozym 435, Lipozyme RM IM, and Lipozyme TL IM from Novozymes) were tested, with Lipozyme TL IM the most effective, showing the highest conversion. Biodiesel conversion from several edible and non-edible oil feedstocks reached [92%. Higher conversion (99.0%) was obtained in a shorter time by employing repeated batch processes with optimized conditions: 44.3 g (500 mM) canola oil, a substrate molar ratio (methanol:oil) of 3:1, an enzyme loading of 20 wt% (of the oil used), at 30°C, 100 bar, and 300 rpm agitation. The enzyme maintained 80.2% of its initial stability after being reused eight times. These results suggest that this method produces biodiesel energy-efficiently and environment-friendly.

Research paper thumbnail of Hydrogen production from biodiesel byproduct by immobilized Enterobacter aerogenes

The recent rapid growth of the biodiesel industry has generated a significant amount of glycerol ... more The recent rapid growth of the biodiesel industry has generated a significant amount of glycerol as a byproduct. As a result, the price of glycerol is currently relatively low, making it an attractive starting material for the production of chemicals with higher values. Crude glycerol can be directly converted through microbial fermentation into various chemicals such as hydrogen. In this study, we optimized immobilization of a facultative hydrogen producing microorganism, Enterobacter aerogenes, with the goal of developing biocatalysts that was appropriate for the continuous hydrogen production from glycerol. Several carriers were tested and agar was found to be the most effective. In addition, it was clearly shown that variables such as the carrier content and cell loading should be controlled for the immobilization of biocatalysts with high hydrogen productivity, stability, and reusability. After optimization of these variables, we were able to obtain reusable biocatalysts that could directly convert the byproduct stream from biodiesel processes into hydrogen in continuous processes.

Research paper thumbnail of Pilot scale treatment of textile wastewater by combined process (fluidized biofilm process–chemical coagulation–electrochemical oxidation)

Water Research, 2002

The performance of pilot scale combined process of fluidized biofilm process, chemical coagulatio... more The performance of pilot scale combined process of fluidized biofilm process, chemical coagulation and electrochemical oxidation for textile wastewater treatment was studied. In order to enhance biological treatment efficiency, two species of microbes, which can degrade textile wastewater pollutants efficiently, were isolated and applied to the system with supporting media. FeCl 3 Á 6H 2 O, pH 6 and 3.25 Â 10 À3 mol/l were determined as optimal chemical coagulation condition and 25 mM NaCl of electrolyte concentration, 2.1 mA/cm 2 of current density and 0.7 l/ min of flow rate were chosen for the most efficient electrochemical oxidation at pilot scale treatment. The fluidized biofilm process showed 68.8% of chemical oxygen demand (COD) and 54.5% of color removal efficiency, even though using relatively low MLSS concentration and short sludge retention time. COD and color removals of 95.4% and 98.5% were achieved by overall combined process. The contribution of fluidized biofilm process to the overall combined process was increased over 25.7% of COD reduction and 20.5% of color reduction by adopting support media in biological treatment. It can be thought that the fluidized biofilm process was effective, and pollutant loading on post-treatment was pretty much decreased by this system. This combined process was highly competitive in comparison to the other similar combined systems. It was concluded that this combined process was successfully employed and much effectively decreased pollutant loading on post-treatment for textile wastewater treatment at pilot scale. r

Research paper thumbnail of COD reduction and decolorization of textile effluent using a combined process

Journal of Bioscience and Bioengineering, 2003

This study showed the effectiveness of biological pretreatment involving appropriate microorganis... more This study showed the effectiveness of biological pretreatment involving appropriate microorganisms and suitable support media in a combined process. The combined process consists of biological pretreatment, chemical coagulation and electrochemical oxidation. COD and color were reduced by 95.4% and 98.5% by the combined process, respectively.

Research paper thumbnail of Upgrading of anaerobic digestion by incorporating two different hydrolysis processes

Journal of Bioscience and Bioengineering, 2005

The purpose of this study was to increase the efficiency of anaerobic digestion of waste activate... more The purpose of this study was to increase the efficiency of anaerobic digestion of waste activated sludge (WAS). Either thermochemical or biological hydrolysis was used as a pretreatment and the effects of both were investigated and compared. Two different three-stage digestion systems showed improved performance, although thermochemical hydrolysis showed better results than biological hydrolysis in a bench-scale operation. After anaerobic digestion with thermochemical pretreatment, the total chemical oxygen demand (tCOD) reduction, volatile solid (VS) reduction, methane yield and methane biogas content were 88.9%, 77.5%, 0.52 m 3 /kg VS and 79.5%, respectively. These results should help in determining the best hydrolysis pretreatment process for anaerobic digestion and in improving the design and operation of the large-scale treatment of WAS by anaerobic digestion with hydrolysis systems.

Research paper thumbnail of Biokinetic Parameter Estimation for Degradation of 2,4,6-Trinitrotoluene (TNT) with Pseudomonas putida KP-T201

Journal of Bioscience and Bioengineering, 2002

The purpose of this study is to determine the biodegradation kinetics of 2,4,6-trinitrotoluene (T... more The purpose of this study is to determine the biodegradation kinetics of 2,4,6-trinitrotoluene (TNT) by a newly isolated microorganism.

Research paper thumbnail of Bioremediation of 2,4,6-Trinitrotoluene Contaminated Soil in Slurry and Column Reactors

Journal of Bioscience and Bioengineering, 2003

Two composting systems were compared on a laboratory scale as a bioremediation technology for deg... more Two composting systems were compared on a laboratory scale as a bioremediation technology for degradation or immobilization of 2,4,6-trinitrotoluene (TNT) in contaminated soils. The first compost was aerated from the beginning whereas the second compost was only aerated after an anaerobic prephase of 65 days. In the first compost system the TNT concentration declined rapidly by 92% but, at the end, TNT could be partially recovered. During the anaerobic prephase of the second compost system, TNT was almost completely converted to aminodinitrotoluenes, which during the subsequent aeration almost entirely disappeared. In addition, the second compost generated less toxic material than the first one as confirmed by inhibition of bioluminescence of Vibrio fischeri.

Research paper thumbnail of Optimization for Biodegradation of 2,4,6-Trinitrotoluene (TNT) by Pseudomonas putida

Journal of Bioscience and Bioengineering, 2003

In this study, a strain of Pseudomonas putida KP-T202, isolated from the soil in a contaminated s... more In this study, a strain of Pseudomonas putida KP-T202, isolated from the soil in a contaminated site, degraded 2,4,6-trinitrotoluene (TNT). In order to make this biodegradation process commercially feasible and reduce biodegradation time, optimal environmental factors are determined. At an initial concentration of 100 mg/l, TNT was totally degraded within 15 h under aerobic conditions. The optimal conditions for the biodegradation of TNT were found to be 30 degrees C, pH 7, 1% corn steep liquor (CSL), 0.025% NH,CI and 0.1% Tween 80; the reaction rate constant was 0.348 h(-1) These environmental conditions can be used to improve the efficiency of large-scale reactors for the treatment of TNT-contaminated wastewater and soil. In addition, the intermediates were identified as 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene, 2,4-dinitrotoluene and 2,6-dinitrotoluene.

Research paper thumbnail of COD Reduction and Decolorization of Textile Effluent Using a Combined Process

Journal of Bioscience and Bioengineering, 2003

This study showed the effectiveness of biological pretreatment involving appropriate microorganis... more This study showed the effectiveness of biological pretreatment involving appropriate microorganisms and suitable support media in a combined process. The combined process consists of biological pretreatment, chemical coagulation and electrochemical oxidation. COD and color were reduced by 95.4% and 98.5% by the combined process, respectively.

Research paper thumbnail of Synthesis of carbohydrate biomass-based furanic compounds bearing epoxide end group(s) and evaluation of their feasibility as adhesives

Journal of Adhesion Science and Technology, 2013

Current issues of energy and environment prompt us to replace fossil-based resources with renewab... more Current issues of energy and environment prompt us to replace fossil-based resources with renewable and sustainable ones. In this regard, carbohydrate biomass photosynthesized from atmospheric carbon dioxide attracts much attention due to its abundance and availability. Recently, furanic compounds that can be derived from carbohydrate biomass are highlighted as promising substitutes for aromatic compounds that are totally dependent on petroleum

Research paper thumbnail of Optimization and morphology for decolorization of reactive black 5 by Funalia trogii

Enzyme and Microbial Technology, 2007

The influence of the various carbon and nitrogen sources on the decolorization of reactive black ... more The influence of the various carbon and nitrogen sources on the decolorization of reactive black 5 (RB 5) by Funalia trogii was examined using a classical method of medium optimization. Of the carbon sources examined as effective co-substrates, fructose, glycerol, and starch were found to be satisfactory, whereas lactose and sucrose were not. When ammonium tartrate, yeast extract, and peptone were used as nitrogen sources, the decolorization rate was high. An optimal pH is important for fungal growth, and our system operated best at a pH 5-6. By combining a Latin square design with a classical method of medium optimization, the essential medium components were identified using liquid culture experiments. Morphological changes of F. trogii were found to be significantly related to decolorization, and changes in fractal dimension followed RB 5-decolorizing enzyme activity.

Research paper thumbnail of Decolorization of acid black 52 by fungal immobilization

Enzyme and Microbial Technology, 2006

In order to achieve an effective decolorization with Funalia trogii, fungal immobilization and re... more In order to achieve an effective decolorization with Funalia trogii, fungal immobilization and repeated batch experiment were investigated. The activities of three enzymes, namely laccase, lignin peroxidase (LiP) and manganese peroxidase (MnP), were reported during decolorization of acid black 52 under the condition of immobilized and suspended fungal mycelia. When F. trogii were immobilized in Na-alginate, the cell viability increased as alginate concentration was increased, although the cell concentration decreased. Na-alginate of 4% (w/v) was an optimum concentration. Decolorization rate by fungal immobilization was higher than that by suspended cultivation. Decolorization could be stably maintained with the repeated batch experiments during long period (at least for 300 h).

Research paper thumbnail of Optimization of backflushing conditions for ceramic ultrafiltration membrane of disperse dye solutions

Desalination, 2007

ABSTRACT

Research paper thumbnail of Decolorization of disperse and reactive dye solutions using ferric chloride

Desalination, 2004

The composition of wastewater from dyeing and textile processes is highly variable depending on t... more The composition of wastewater from dyeing and textile processes is highly variable depending on the dyestuff type; typically it has a high chemical oxygen demand. This study examined the decolorization of some of the most commonly used disperse and reactive ...

Research paper thumbnail of Electrochemical oxidation of polyvinyl alcohol using a RuO2/Ti anode

Desalination, 2003

Polyvinyl alcohol (PVA), known as the dominant contributor of chemical oxygen demand (COD) in tex... more Polyvinyl alcohol (PVA), known as the dominant contributor of chemical oxygen demand (COD) in textile wastewater, is very difficult to decompose by conventional treatment technologies. In this study, electrochemical oxidation using a RuO/Ti anode was applied to treat a PVA solution. The mechanisms of PVA degradation and COD destruction were investigated, while the operating parameters affecting the mechanisms were also studied. The parameters investigated included current density, PVA concentration in waste stream, the rate of electrolyte consumption of sodium chloride, and the feed rate of wastewater. The overall mass transport behavior of electrochemical oxidation of PVA was explained by the mathematical relationship of dimensionless numbers such as the Reynolds, Schmidt and Sherwood numbers.

Research paper thumbnail of Decolorization of disperse and reactive dyes by continuous electrocoagulation process

Desalination, 2002

The electrocoagulation process was developed to overcome the drawbacks of conventional wastewater... more The electrocoagulation process was developed to overcome the drawbacks of conventional wastewater treatment technologies. This process is very effective in removing organic pollutants including dyestuffwastewater and allows for the reduction of sludge generation. The purposes of this study were to investigate the effects of the operating parameters, such as current density, electrode number, electrolyte concentration, electrode gap, dyestuff concentration, pH of solution and inlet flow rate, on decoiorization by continuous electrocoagulation. The dye removal efficiencies and reaction rate constants from the curves following the first-order relationship ofelectrocoagulation were calculated. In addition, from the points of power consumption, the effects of the operating parameters were also searched. Finally, the behaviors of decolorization according to dyestuff types, i.e., disperse dye and reactive dye, were also examined.

Research paper thumbnail of Decolorization of dye solutions by a membrane bioreactor (MBR) using white-rot fungi

Desalination, 2004

In this study a membrane bioreactor (MBR) using white-rot fungi was used for the decolorization o... more In this study a membrane bioreactor (MBR) using white-rot fungi was used for the decolorization of dye solutions. The decolorization of dye solutions by Trametes versicolor KCTC 16781 and membrane filtration were combined, and the applicability of this process was investigated ...

Research paper thumbnail of Facile Single-Step Conversion of Macroalgal Polymeric Carbohydrates into Biofuels

ChemSusChem, 2010

ABSTRACT Red macroalgae-derived agar is a renewable and sustainable resource. For the synthesis o... more ABSTRACT Red macroalgae-derived agar is a renewable and sustainable resource. For the synthesis of HMF under solid Brønsted acid conditions, agar shows a unique reaction pattern and affords higher yields than land plant-based polymeric carbohydrates. Agar can be directly converted into next-generation biofuels by one-pot reactions and readily isolated by using a general workup procedure, which is crucial for a large-scale process.

Research paper thumbnail of Strain development and medium optimization for fumaric acid production

Biotechnology and Bioprocess Engineering, 2010

Rhizopus oryzae RUR709 mutant was isolated based on halo size from selection medium via mutagenes... more Rhizopus oryzae RUR709 mutant was isolated based on halo size from selection medium via mutagenesis with UV and γ-rays, and the production of fumaric acid in the submerged fermentation was assessed. The maximum concentration of fumaric acid was obtained using 0.5% corn steep liquor (CSL) as the nitrogen source. Organic nitrogen sources were shown to be more effective in fumaric acid production than inorganic nitrogen sources. Using optimum medium obtained by response surface methodology (RSM), the maximum concentration of fumaric acid achieved in flask culture was 26.2 g/L, which is fairly close to the 27.4 g/L predicted by the model. The highest concentration of fumaric acid in the stirred-tank reactor generated by the R. oryzae RUR709 mutant was 32.1 g/L and yield (0.45 g/g) and productivity (0.32 g/L/h) were highest at 4 days.

Research paper thumbnail of Biodegradation and biosorption for decolorization of synthetic dyes by Funalia trogii

Biochemical Engineering Journal, 2007

The objective of this study was to investigate two major mechanisms for decolorization of dyes by... more The objective of this study was to investigate two major mechanisms for decolorization of dyes by cultivation of fungi on either a solid or in a liquid phase and to confirm the possibility of practical application via repeated-batch cultivation. The decolorization of six commercial dyes with 10 fungal strains was studied. Enzyme activity, decolorization trends and decolorization mechanisms were monitored. Under the experimental conditions, extracellular laccase and manganese peroxidase (MnP), but not lignin peroxidase (LiP), were detected. The decolorization mechanisms by F. trogii ATCC 200800 involved a complex interaction of enzyme activity and biosorption. This study suggests that it is possible to decolorize a high concentration of commercial dyes, which would be a great advance in the treatment of dye containing wastewater. These methods may have a potential application for dye decolorization and for textile effluent treatment.