• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.712-718
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• 2005

Stepwise reductions of glucose and Orange II concentration were observed from the experiment of both white-rot fungi such as T. versicolor and P. chrysosporium. As a result, typical removal patterns in those dual substrate system were categorized through several distinctive steps: initial lag period, primary and secondary carbon consumption periods. Also, based on the total removal amounts of Orange II, COD and Color during the experimental period, similar removal extent were observed from both species experiments, within the maximal error range of 5%. However, it was refereed that the internal steps of Orange II removal on enzymatic level should be different between two species: Enzyme Lac showed good affinity for Orange II removal in T. versicolor, however in P. chrysosporium enzyme LiP represented more close affinity to the similar experimental condition. Thus, even though the superficial removal amount of calcitrant Orange II at different fungal species was merely similar, removal pathway of enzymatic levels and intermediates produced during the fungal decomposition would be different.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.977-983
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• 2002

This study was performed to establish the precise and rapid method to distinguish croakers through the pigment analysis of colored imported white croakers for adultration. We surveyed the coloring behaviors, extraction test by water and organic solvent and using pigments such as targeting, curcumine, and azo dye products. The pigment of yellow croaker is not stained on wet cloth or tissue which is rubbed on epidermis of yellow croaker and was not eluted in water extraction test, while adulterated pigments were easily extracted by water and acetone, but edible diluted yellow, Yellow No. 4 and Yellow No. 5 were not extracted. Reactive pigment was detected easily by extraction with water and dispersed pigment was also detected by extraction test. As a result of discoloring characteristics of carotene having similar structure to yellow croaker and azo dye by oxidation and reduction, azo dyes were not discolored by oxidation with sodium percarbonate or peracetic acid but that were discolored by oxidation with Fenton reagent after 1hr and by hypochlorite promptly. On the other hand, carotenes were not discolored by sodium precarbonate and Fenton reagent but discolored by sodium hypochlorite after 2 hr and by peracetic acid promptly. Azo dyes were discolored by reduction with sodium hydrosulfite and sodium carbonate but carotenes were not discolored by these reagents. This discoloring test was applicable to detect adulterated pigments and other marine product.

• 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.

• Journal of the Korean Chemical Society
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• v.27 no.3
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• pp.213-217
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• 1983

Devices that mimic the natural photosynthetic pathway are of considerable interest as fuel sources. Quantum yield of viologen radical formation in several water-in-oil microemulsion system were measured. The yield of hexadecylviologen radical formation in microemulsion system using EDTA as an electron donor, ruthenium bipyridinium complex as photosensitizer, and hexadecylviologen as an electron acceptor was 12%. When benzylnicotinamide was inserted in the interface of the microemulsion and azo compound was dissolved in oil face, the quantum yield of hydroazo compound was 0.16. Organic dye (Rose bengal) was used as photosensitizer for the photoinduced electron transfer reaction. In anionic microemulsion no electrontransfer was observed.

• Textile Coloration and Finishing
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• v.27 no.4
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• pp.229-244
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• 2015

The effects of synthesis conditions on characteristics of the calcium-azo complex pigment, C.I. Pigment Red 57:1, were studied. It was mainly considered that the industrially required synthesis conditions for lowering electrical conductivity of the pigment solution keeping pigment quality such as particle size and color characteristics. Three parameters were chosen as control factors during the synthesis. The first was the amount of hydrochloric acid added to transform sodium nitrite into nitrous acid. The second was the amount of calcium chloride added to insolubilize the synthesized azo dye. The final factor was pH control during the coupling reaction. The electrical conductivity and pigment aggregate particle size were dependent on the amount of hydrochloric acid and calcium chloride. Higher HCl concentration gave brighter yellowish-red color because of smaller particle aggregate size and narrower size distribution. Amount of charged ions in the synthesis process might affect the "lake" formation resulting different particle aggregate size and color shade.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.165-169
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• 2006

A Citrobacter sp. MB 2, azo dyes decolorizing bacterium, was isolated from the wastewater and soil and identified as Citrobacter sp.. It was examined that optimum conditions for culture media were 0.5% of sucrose, 1.0% of yeast extract, 0.1% of $K_2HPO_4$, 0.1% of $NaHCO_3$ per distilled water. The best efficient condition of culture was obtained at pH 7.0, $30^{\circ}C$ and aerobic shaking culture. The number of Citrobacter sp. MB2 in optimum medium was increased more than 7 fold compared to basal medium and 50 fold compared to nutrient broth. This strain was exhibited strong resistance against metal salts and antibiotics (ampicillin and penicillin G).

• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1383-1390
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• 2019

In this study, we expressed cotA laccase from Bacillus subtilis on the surface of B. subtilis spores for efficient decolorization of synthetic dyes. The cotE, cotG, and cotY genes were used as anchoring motifs for efficient spore surface display of cotA laccase. Moreover, a $His_6$ tag was inserted at the C-terminal end of cotA for the immunological detection of the expressed fusion protein. Appropriate expression of the CotE-CotA (74 kDa), CotG-CotA (76 kDa), and CotY-CotA (73 kDa) fusion proteins was confirmed by western blot. We verified the surface expression of each fusion protein on B. subtilis spore by flow cytometry. The decoloration rates of Acid Green 25 (anthraquinone dye) for the recombinant DB104 (pSDJH-EA), DB104 (pSDJH-GA), DB104 (pSDJH-YA), and the control DB104 spores were 48.75%, 16.12%, 21.10%, and 9.96%, respectively. DB104 (pSDJH-EA) showed the highest decolorization of Acid Green 25 and was subsequently tested on other synthetic dyes with different structures. The decolorization rates of the DB104 (pSDJH-EA) spore for Acid Red 18 (azo dye) and indigo carmine (indigo dye) were 18.58% and 43.20%, respectively. The optimum temperature for the decolorization of Acid Green 25 by the DB104 (pSDJH-EA) spore was found to be $50^{\circ}C$. Upon treatment with known laccase inhibitors, including EDTA, SDS, and $NaN_3$, the decolorization rate of Acid Green 25 by the DB104 (pSDJH-EA) spore decreased by 23%, 80%, and 36%, respectively.

• Journal of Microbiology and Biotechnology
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• v.31 no.7
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• pp.967-977
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• 2021

A total of 37 bacterial isolates were obtained from dye-contaminated soil samples at a textile processing factory in Nakhon Ratchasima Province, Thailand, and the potential of the isolates to decolorize and biotransform azo dye Reactive Red 141 (RR141) was investigated. The most potent bacterium was identified as Paenibacillus terrigena KKW2-005, which showed the ability to decolorize 96.45% of RR141 (50 mg/l) within 20 h under static conditions at pH 8.0 and a broad temperature range of 30-40℃. The biotransformation products were analyzed by using UV-Vis spectrophotometry and Fourier-transform infrared spectroscopy. Gas chromatography-mass spectroscopy analysis revealed four metabolites generated from the reductive biodegradation, namely sodium 3-diazenylnaphthalene-1,5-disulfonate (I), sodium naphthalene-2-sufonate (II), 4-chloro-1,3,5-triazin-2-amine (III) and N¹-(1,3,5-triazin-2-yl) benzene-1,4-diamine (IV). Decolorization intermediates reduced phytotoxicity as compared with the untreated dye. However, they had phytotoxicity when compared with control, probably due to naphthalene and triazine derivatives. Moreover, genotoxicity testing by high annealing temperature-random amplified polymorphic DNA technique exhibited different DNA polymorphism bands in seedlings exposed to the metabolites. They compared to the bands found in seedlings subjected to the untreated dye or distilled water. The data from this study provide evidence that the biodegradation of Reactive Red 141 by P. terrigena KKW2-005 was genotoxic to the DNA seedlings.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.843-849
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• 2013

A dye-decolorizing bacterium was isolated from a soil sample and identified as Bacillus thuringiensis using 16S rRNA sequencing. The bacterium was able to decolorize three different textile dyes, namely, Reactive blue 13, Reactive red 58, and Reactive yellow 42, and a real dyehouse effluent up to 80-95% within 6 h. Some non-textile industrially important dyes were also decolorized to different extents. Fourier transform infrared spectroscopy and gas chromatography-mass spectrometer analysis of the ethyl acetate extract of Congo red dye and its metabolites showed that the bacterium could degrade it by the asymmetric cleavage of the azo bonds to yield sodium (4-amino-3-diazenylnaphthalene-1-sulfonate) and phenylbenzene. Sodium (4-amino-3-diazenylnaphthalene-1-sulfonate) was further oxidized by the ortho-cleavage pathway to yield 2-(1-amino-2-diazenyl-2-formylvinyl) benzoic acid. There was induction of the activities of laccase and azoreductase during the decolorization of Congo red, which suggests their probable role in the biodegradation. B. thuringiensis was found to be versatile and could be used for industrial effluent biodegradation.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.04a
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• pp.147-147
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• 2000

본 연구는 화장지용 펼프원료로 저급지인 색지(color ledger)고지를 사용함으로써 생산원 가를 절감하기 위한 목적으로 실시되었다. 일반적으로 색지 고지는 azo dyes, stilbene dyes, c copper phthalocyanine dyes와 같은 직접염료(direct dye)로 착색돼있는 것으로 보고되고있 다[) 한편, 펄프표백에 사용되는 약품은 hydrogen peroxide(HzOz), ozone(03), sodium h hypochloriten업oeD와 같은 산화표백제들과 F AS (formamidine sulfinic acid), sodium h hydrosulfite(NazSz04)와 같은 환원표백제들이 사용되는 것으로 널리 알려져 있다. 보통 화 장지용 펄프는 백색도가 78%이상이 되어야만 제품생산에 사용할 수 있는 것으로 인식되고 있다. 따라서 색지 고지를 이 목표로 달성하기 위한 탈색방법을 확립코자 다음과 같은 2가 지 실험을 실시하였다. 먼저, 색의 3원색인 빨강, 노랑, 파랑색의 색지 고지를 동일한 양으로 혼합하여 PY, HY, YH, YH, HY와 같은 5가지 방법의 실험을 실시하였다. 이중 YH 방법 이 가장 우수한 것으로 나타났다. 이 결과를 근거로 하여 여러 가지 색으로 구성된 색지 고 지가 50% 함유한 백상지 고지를 사용하여 Table과 같은 약품 및 조건으로 표백을 겸한 탈 묵실험을 실시하였다. 이 실험에서 백색도 81.8%, L* 93.3, a* -0.5, b* 4.1의 결과를 얻었다. 색지 고지의 탈색은 Y 단계에서 pH와 온도에 큰 영향을 받는 것으로 본 실험을 통하여 알 수가 있었다.