• Mycobiology
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• v.47 no.2
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• pp.217-229
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• 2019

Two manganese peroxidases (MnPs), MnP1 and MnP2, and a laccase, Lac1, were purified from Trametes polyzona KU-RNW027. Both MnPs showed high stability in organic solvents which triggered their activities. Metal ions activated both MnPs at certain concentrations. The two MnPs and Lac1, played important roles in dye degradation and pharmaceutical products deactivation in a redox mediator-free system. They completely degraded Remazol brilliant blue (25 mg/L) in 10-30 min and showed high degradation activities to Remazol navy blue and Remazol brilliant yellow, while Lac1 could remove 75% of Remazol red. These three purified enzymes effectively deactivated tetracycline, doxycycline, amoxicillin, and ciprofloxacin. Optimal reaction conditions were $50^{\circ}C$ and pH 4.5. The two MnPs were activated by organic solvents and metal ions, indicating the efficacy of using T. polyzona KU-RNW027 for bioremediation of aromatic compounds in environments polluted with organic solvents and metal ions with no need for redox mediator supplements.

• Journal of Environmental Health Sciences
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• v.35 no.4
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• pp.295-303
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• 2009

A simulated wastewater containing the dye Rhodamine B (RhB) was electrolytically treated using a three-dimensional electrode reactor equipped with granular activated carbon (GAC) as particle electrode. The effect of type of packing material (GAC, ACF, Nonwoven fabric fiber coated with activated carbon), amounts of GAC packing (25-100 g), current (0.5-3 A) and electrolyte concentration (0.5-3 g/l) was evaluated. Experimental results showed that performance for RhB decolorization of the 3 three-dimensional electrodes lie in: GAC > Nonwoven fabric fiber > ACF. When considered RhB decolorization, oxidants concentration and electric power, optimum GAC dosage was 50 g. Generated concentration of 3 oxidants ($ClO_2$, free Cl, $H_2O_2$) was increased with increase of applied current, however optimum current for RhB degradation was 2.5 A. The oxidants concentration was increased with increase of NaCl concentration and optimum NaCl dosage for RhB degradation was 1.5 g/l.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.79-82
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• 2017

An inky cap, Coprinus comatus synthesizes and secretes a laccase in the liquid yeast extract peptone dextrose medium. We have successfully purified the enzyme through the ion-exchange chromatography and the preparative gel electrophoresis. The estimated molecular weight was 67 kDa by the SDS-PAGE analysis. Optimum pH was pH 4.3 and optimum temperature was $25^{\circ}C$. The Km value was 0.45 mM and the Vmax was 0.0132 OD/min/unit for o-tolidine. Purified laccase showed 49.3% decolorizing activity against remazol brilliant blue R (RBBR) and 41.6% decolorizing activity against Poly R-478 after 12 h incubation.

• 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.

• Journal of Korean Society on Water Environment
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• v.25 no.2
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• pp.227-234
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• 2009

In this research, a retrofitting process, which consists of a pretreatment system (coagulation) for dye wastewater combined with a biological nutrient system (MLE process using media), for a sewage treatment plant that has to treat dye wastewater efficiently with domestic wastewater were developed and a pilot plant was operated for verifying adoptability and performance of the developed advanced process for dye wastewater. From the results of the pilot plant operation, BOD 52.9%, $COD_{Cr}$ 55.9%, and color 71.3% were removed in pretreatment of coagulation process and the biodegradability of dye wastewater was improved to $0.32{\sim}0.59BOD/COD_{Cr}$ of the coagulated wastewater from $0.29{\sim}0.43BOD/COD_{Cr}$ of the raw dye wastewater. The final effluent concentrations were BOD of 8 mg/L, $COD_{Cr}$ of 43 mg/L, $COD_{Mn}$ of 18 mg/L, T-N of 8 mg/L, and T-P of 1.3 mg/L, respectively. Color was removed from 1655 to 468 unit by coagulation and then to 123 unit by MLE process. The HPLC analysis of aromatic amines in wastewater showed that decolorization was achieved by cometabolism while aromatic amines were produced by cleavage of azo bonds under anaerobic conditions and these products were removed in an aerobic tank subsequently. Nitrification rates of attached and suspended microorganisms were evaluated comparatively and the acclimating conditions of bacteria on media were validated by the scanning electron microscope.

• The Korean Journal of Mycology
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• v.40 no.2
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• pp.98-103
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• 2012

This study has been conducted to screen the decolorization of 4 aromatic synthetic dyes and production of ligninolytic enzymes by 4 white rot fungi such as Bjerkanderia adusta, Cerrena unicolor, Pleurotus pulmonarius and Abortiporus biennis. It was found that B. adusta, C. unicolor, and P. pulmonarius have the ability to efficiently decolorize congo red and moderately decolorized amaranth and orange G in solid and liquid culture media. However, the decolorization rate of 4 synthetic dyes by A. biennis was relatively low. The decolorization of congo red, amaranth, orange G were related to the growth rate of the fungal mycelia in the solid medium. But, the all fungi tested did not efficiently decolorize methylene blue in the liquid culture media. To investigate the production of ligninolytic enzymes in media containing aromatic compounds, fungi were cultured in 1% naphthalene supplemented potato dextrose broth medium. All fungi tested had the capability to produce laccase, lignin peroxidase and manganese peroxidase, and B. adusta was the best ligninolytic enzymes producing white rot fungus among other fungi tested.

• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.58-64
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• 2020

BACKGROUND: Most of the researches on the dye removal using ozonation have been focused on the removal efficiency. However, the research on their removal characteristics and mechanism according to the reaction time has been still insufficient. METHODS AND RESULTS: In this study, the effects of initial pH and dye concentration with reaction time on the degradation characteristics of methyl orange (MO) and methylene blue (MB) by ozonation were evaluated. The degradation efficiency of MB by ozonation increased with increasing pH. On the other hand, the degradation efficiency of MO by ozonation did not show a significant difference with varing pH. The both MO and MB by ozonation were decomposed within 30 min irrespective of the dye concentration, but the decomposition rates of dyes were faster at lower initial dye concentration. The decomposition efficiency of total organic carbon (TOC) in each dye solution by ozonation was low, which was found to be effective for partial decomposition such as decolorization rather than complete degradation of the dye. CONCLUSION: Overall, ozonation was an effective method for removing nondegradable dyes. However, it is necessary to study the optimization of dye degradation under various environmental conditions for ozonation.

• Journal of Mushroom
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• v.20 no.2
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• pp.86-91
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• 2022

Pleurotus eryngii, a white rot fungus, produces two extracellular lignin-degrading enzymes, laccase and manganese peroxidase (MnP). Owing to these enzymes, P. eryngii efficiently degrades synthetic chemicals such as azo, phthalocyanine, and triphenyl methane dyes. In this study, we investigated the degradation processes of four aromatic dyes, congo red (CR), methylene blue (MB), crystal violet (CV), and malachite green (MG), by P. eryngii under solid and liquid culture conditions. CR and MG were the most quickly degraded under solid and liquid culture conditions, respectively. However, compared to CR, CV, and MG, MB was not degraded well under both culture conditions. The activities of ligninolytic enzymes (laccase and MnP) were also investigated. Laccase was identified to be the major enzyme for dye degradation. A positive relationship between decolorization and enzyme activity was observed for CR, MB, and CV degradation. In contrast, decolorization of MG ensued after high enzyme activity. These results indicate that the degradation process differs between MG and the other aromatic dyes. Therefore, P. eryngii could be a potential tool for the bioremediation of synthetic aromatic dye effluent.

• Journal of the Korean Ceramic Society
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• v.53 no.1
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• pp.56-62
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• 2016

A heterogeneous $Bi_2S_3/TiO_2$ composite catalyst was synthesized via a green ultrasonic-assisted method and characterized by XRD, SEM, EDX, TEM analysis. The results clearly show that the $TiO_2$ particles were homogenously coated with $Bi_2S_3$ particles, indicating that $Bi_2S_3$ particle agglomeration was effectively inhibited after the introduction of anatase $TiO_2$. The Texbrite BA-L (TBA) degradation rate constant for $Bi_2S_3/TiO_2$ composites reached $8.27{\times}10^{-3}min^{-1}$ under visible light, much higher than the corresponding value of $1.04{\times}10^{-3}min^{-1}$ for $TiO_2$. The quantities of generated hydroxyl radicals can be analyzed by DPCI degradation, which shows that under visible light irradiation, more electron-hole pairs can be generated. Finally, the possible mechanism for the generation of reactive oxygen species under visible-light irradiation was proposed as well. Our result shows the significant potential of $Bi_2S_3$-semiconductor-based $TiO_2$ hybrid materials as catalysts under visible light for the degradation of industry dye effluent substances.

• Journal of the Korean Ceramic Society
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• v.52 no.3
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• pp.173-179
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• 2015

We report the facile synthesis of graphene-$CdLa_2S_4$ composite through a facile solvothermal method at low temperature. The as-prepared products were characterized by X-ray diffraction (XRD) and by Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and BET analysis, revealing the uniform covering of the graphene nanosheet with $CdLa_2S_4$ nanocrystals. The as-prepared samples show a higher efficiency for the photocatalytic degradation of typical MB dye compared with P25 and $CdLa_2S_4$ bulk nanoparticles. The enhancement of visible-light-responsive photocatalytic properties by decolorization of Rh.B dye may be attributed to the following causes. Firstly, graphene nanosheet is capable of accepting, transporting and storing electrons, and thus retarding or hindering the recombination of the electrons with the holes remaining on the excited $CdLa_2S_4$ nanoparticles. Secondly, graphene nanosheet can increase the adsorption of pollutants. The final cause is that their extended light absorption range. This work not only offers a simple way to synthesize graphene-based composites via a one-step process at low temperature but also a path to obtain efficient functional materials for environmental purification and other applications.