• Journal of Life Science
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• v.25 no.12
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• pp.1458-1469
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• 2015

Many organic solvent-tolerant bacteria have been isolated from all environments such as soil, waste-water, even deep sea after first isolation report of organic solvent-tolerant bacterium. Most organic solvent- tolerant isolates have been determined to be Gram-negative bacteria, because Gram-negative bacteria have inherent tolerance property toward hostile organic solvents more than Gram-positive bacteria. The mechanisms of organic solvent tolerance have been elucidated extensively using mainly organic solvent-tolerant Gram-negative bacteria. The solvent-tolerance mechanisms in Gram-positive bacteria can be found in comparatively recent research. Organic solvents exhibited different toxicity depending on the solvent, and the tolerance levels of organic solvent-tolerant bacteria toward organic solvents were also highly changeable among species and strains. Therefore, organic solvent-tolerant bacteria could coped with solvent toxicity and adapted to solvent stress through the multifactorial and multigenic adaptative strategies. They could be survived even in the hyper concentrations of organic solvents by mechanisms which include: changes in cell morphology and cell behaviour, cell surface modifications, cell membrane adaptations, solvent excretion pumps, chaperones and anti-oxidative response. The aim of this work is to review the representative solvent tolerant bacteria and the adaptative and tolerance strategies toward organic solvents in organic solvent-tolerant bacteria, and their potential industrial and environmental impact.

• Journal of Environmental Health Sciences
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• v.20 no.4
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• pp.10-16
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• 1994

A Study was performed in order to measure mixed organic solvent concentrations in air of painting operations during January 5-28, 1991. The mixed organic solvent concentrations were analyzed by the gas chromatography. The results were as follows: 1. The detection of organic solvent was highest in aromatic hydrocarbon(68%), and followed by aliphatic hydrocarbon (18%), and ketone (14%). 2. The detection of organic solvent by component category was highest in the grid class solvent (79.4%), and followed by the 3rd class solvent (20.6%). 3. Number of cases exceeding TLVS of mixed solvent level in air was highest on dipping operation (44%), and followed by spray operation (40%), dry and washing operation (33%), and adhensive operation (12%).

• Korean Journal of Occupational Health Nursing
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• v.24 no.2
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• pp.67-75
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• 2015

Purpose: The objective of the present study was to evaluate the effects of occupational exposure to low dose organic solvents on the prevalence of cardiovascular risk factors. Methods: Study design was retrospective cohort study subjected on 191 exposures and 118 controls working in a petrochemical manufacture company. The eight indicators related to CVD risk were followed up for five years from 2008 to 2012. The risk level was compared during the follow up years and subject's characteristics, and the change of risk level were analyzed with repeated measures ANOVA and multiple logistic regression analysis. Results: At the start year 2008, the rate over cutoff value (ROCV) of BS (p<.001) and mean systolic BP (p=.017) were higher in organic solvent exposure group and the others showed no difference. And by the subject's characteristics, odds ratio of the ROCV of BS were higher in organic solvent exposure group and work shift group as 2.51 and 3.07. Comparing the results in 2012 to those of 2008, cardiovascular disease risk in organic solvent exposure group was about 1.5 times higher than that of in the control group. Conclusion: Gradual increase in the CVD risk was identified in organic solvent exposure group. However, the risk might be influenced by shift work and bad behaviors rather than organic solvent exposure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.300-303
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• 1999

For the fast dry of the aqueous tape, the process which water was replaced by organic solvent was proposed. So-called, it was the solvent washing dry, Three organic solvents (methanol, ethanol, and acetone) were selected for the washing solvent. The weight loss of the washed tapes was measured to evaluate the dry rate of the tapes and dried tapes were examined the generation of the cracks with the variations of the organic solvent and the washing time. Methanol, ethanol, and acetone were all available organic solvents for this method. The tapes washed in methanol, ethanol, and acetone were dried rapidly for twenty minutes. After thirty minutes, the weight losses were not any more. The solvent of the lower surface tension can decreases the crack of dried tape. If solvent substitutes water completely, though it was fast dried, crack can be eliminated. The tape casting system was designed for the solvent washing dry and prepared. An homogeneous tape was established by continuous tape casting process.

• The Korean Journal of Ceramics
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• v.7 no.2
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• pp.55-57
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• 2001

For the fast dry of the aqueous tape, the process which water was replaced by organic solvent was proposed. Socalled, it was the solvent washing dry. Three organic solvents (methanol, ethanol and acetone) were selected for the washing solvent. The weight loss of the washed tapes was measured to evaluate the dry rate of the tapes and dried tapes were examined the generation of the cracks with the variations of the organic solvent and the washing time. Methanol, ethanol and acetone were available organic solvents for this method. The tapes washed in methanol, ethanol and acetone were dried rapidly for twenty minutes. After thirty minutes, the weight losses were not found any more. The solvent of the lower surface tension can decreases the crack of dried tape. If solvent substitutes water completely, though it was fast dried, crack can be eliminated.

• KSBB Journal
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• v.27 no.1
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• pp.61-66
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• 2012

In the screening process of organic solvent tolerant bacteria showing good growth in media containing several kinds of organic solvents, one strain was isolated and identified as Bacillus sp. BCNU 5006. The strain was able to tolerate many organic solvents including benzene, toluene, xylene, octane, dodecane, butanol and ethylbenzene. Likewise, it could also utilize these solvents as the sole source of carbon with significant enzyme production. The lipolytic enzyme stability of Bacillus sp. BCNU 5006 was studied in the presence of several kinds of solvents at a 25% (v/v) concentration. The highest enzyme stability was observed in the presence of octane (107%), followed by ethylbenzene (88%), decane (86%), and chloroform (85%). Especially, BCNU 5006 lipase was determined to be more stable than immobilized enzyme (Novozyme 435) in the presence of octane, chloroform and xylene. This organic solvent tolerant Bacillus sp. BCNU 5006 could be expected as a potential bioremediation agent and biocatalyst for biodegradation and provide on organic-solvent-based enzymatic synthetic method in industrial chemical processes.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.E
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• pp.27-40
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• 1998

The solubility characteristics of organic compounds were studied in terms of the extraction efficiency as a function of the polarity of the organic solvent, and the acidity of water in urban aerosol samples collected in University of East Anglia (UEA), Norwich, England. The extraction efficiency of organic compounds were evaluated with respect to the organic carbon, -nitrogen and -hydrogen by means of a wide range of solvent which include polar and nonpolar organic solvents as well as acids and alkaline water. In addition, after being dissolved in aqueous solution, the aqueous chemistry of organic compounds were studied in terms of the organic metal complexes in aerosol, which were studied with oxalic acid, copper, and zinc. The results of this study indicate that solubility characteristics of organic compounds depend on the polarity of the solvents and the acidity of the solvents. In particular, some organic compounds are water soluble, even though they are much smaller than acetone soluble fractions. In the comparison between polar organic solvent extraction and non- polar organic solvent extraction, it can be thought that significant fraction of organic compounds analysed in the aerosol samples, are polar organic compounds because of the higher extraction efficiencies of organic compounds in polar organic solvent extraction than in nonpolar organic solvent extraction. Regarding the study of the oxalic -metal complexes, it can be thought that most oxalic acids are present in the form of oxalic -copper complexes in the aerosols collected at UEA.

• Elastomers and Composites
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• v.54 no.3
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• pp.188-200
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• 2019

Rubber articles contain various organic additives such as antidegradants, curing agents, and processing aids. It is important to extract and analyze these organic additives. In this paper, various extraction methods of organic additives present in rubber composites were introduced (solvent extraction, Soxhlet extraction, headspace extraction, and solid-phase microextraction), and the extracts were characterized using gas chromatography/mass spectrometry (GC/MS). Solvent and Soxhlet extractions are easy-to-perform and commonly used methods. Efficiency of solvent extraction varies according to the type of solvent used and the extraction conditions. Soxhlet extraction requires a large volume of solvent. Headspace sampling is suitable for extracting volatile organic compounds, while solid-phase extraction is suitable for extracting specific chemicals. GC/MS is generally used for characterizing the extract of a rubber composite because most components of the extract are volatile and have low molecular weights. Identification methods of chemical structures of the components separated by GC column were also introduced.

• Membrane Journal
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• v.32 no.1
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• pp.50-56
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• 2022

In this work, the solvent permeation and separation performance of organic solvent nanofiltration (OSN) membranes were evaluated. Particularly, the PuraMem (PM) series developed for nonpolar solvents were analyzed and tested in dead-end filtration system. PM membranes exhibited higher permeance for nonpolar solvents compared to polar solvents, and their rejection data did not follow conventional trends with respect to solute size. The data showed that simple solution-diffusion model is not suitable to describe the OSN membrane behavior, and a better solvent-solute-membrane interaction parameter must be developed.

• Journal of Preventive Medicine and Public Health
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• v.25 no.2 s.38
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• pp.162-171
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• 1992

The hematologic effect by low-concentration and repeated exposure to mixed organic solvent remains obscure. This study was performed to evaluate the hematologic effect by mixed organic solvent exposure, especially on the type of anemia by mean corpuscular volume(MCV) and red blood cell distribution width(RDW). The subject were 64 organic solvent workers(male 4, female 60) and 78 general workers(male 18, female 60) who showed anemic tendency in worker's health examination which carried out by Pusan Paik Hospital from January to December, 1988. The author gained some hematologic findings(hemoglobin, hematocrit, RBC, WBC, MCV, MCHC, platelet count, ESR, RDW) from auto-analysis method by coulter counter S plus IV, and compared the type of anemia by MCV and RDW. In the pilot study for estimating the prevalence of anemia according to the type of b, the prevalence rate was higher in organic solvent workers than in public officials as 10.9% and 4.1% respectively. There were statistical significance in the value of hemoglobin, hematocrit, MCV, MCHC, platelet count, ESR, RDW between the two study groups with more severe anemic tendency in organic solvent workers. The type of anemia in organic solvent workers was microcytic and anisocytic with the mean value of $68.28{\pm}8.3fL$ of MCV and $19.1{\pm}4.0%$ of RDW.