• Applied Chemistry for Engineering
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• v.9 no.4
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• pp.497-503
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• 1998

The catalytic oxidation of 1.2-dichloroethane was investigated over precious metal supported on alumina using a fixed bed microreactor. Among the catalysts tested, the conversion of 1.2-dichloroethane decreased in the following order : Ru > Pt > Pd $${\sim_=}$$ Rh and Pt was found to be the most active catalyst for the complete oxidation of 1.2-dichloroethane to $CO_2$. Major products containing carbon were vinyl chloride and $Co_2$ at temperature ranging from 200 to $400^{\circ}C$. The presence of vinyl chloride in products suggests that the first step in the oxidation of 1.2-dichloroethane is dehydrochlorination and the second is oxidation of vinyl chloride to $CO_2$. To investigate the effect of HCl on the activity of the complete oxidation, some experiments were conducted by adding HCl to the feed. The presence of HCl increased the conversion of 1.2-dichloroethane below $300^{\circ}C$ owing to the increase of surface acidity, but it didn't affect the conversion above $300^{\circ}C$. The reversible adsorption of HCl onto catalyst surface inhibited the complete oxidation to $CO_2$.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.697-702
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• 2001

Numerical simulations of 1,2 dichloroethane(EDC) pyrolysis are conducted to understand the process on the production of the vinyl chloride monomer(VCM) and by-products. A chemical kinetic mechanism is developed, the adopted scheme involving 44 gas-phase species and 260 elementary forward and backward reactions. Detailed sensitivity analyses and the rates of production analysis are performed on each of the reactions and the various species, respectively. The concentrations of EDC, VCM, and HCI predicted by this mechanism are in good agreement with those deduced from experiments of commercial and laboratory scale. The mechanism is found to accurately predict the VCM yield and the production of by-products by varying the ranges of pyrolysis temperature, residence time, and pressure which impact on the pyrolysis of 1,2 dichloroethane. The influence of reactions related to H atom on the relative sensitivity of EDC becomes important as the residence time increases. The pyrolysis of EDC mainly occurs through $C_{2}H_{4}Cl_{2}+Cl=CH_{2}ClCHCl$.

• Journal of Mechanical Science and Technology
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• v.16 no.1
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• pp.102-108
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• 2002

Numerical simulations of 1, 2 dichloroethane(EDC) pyrolyisis are conducted to understand the process in the production of the vinyl chloride monomer (VCM) and by-products. A chemical kinetic mechanism Is developed, with the adopted scheme involving 44 gas-phase species and 260 elementary forward and backward reactions. Detailed sensitivity analyses and the rates of production analysis are performed on each of the reactions and the various species, respectively. The concentrations of EDC, VCM, and HCI predicted by this mechanism are in good agreement with those deduced from experiments of commercial and laboratory scale. The mechanism is found to accurately predict the EDC yield an(1 the production of by-products by varying the ranges of pyrolysis temperature, residence time, and pressure which impact on the pyrolysis of 1, 2 dichloroethane. The influence of reactions related to H atom on the relative sensitivity of EDC becomes important as the residence time increases. The pyrolysis of EDC mainly occurs through C$_2$H$_4$Cl$_2$+Cl=CH$_2$CICHI+HCI.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.4
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• pp.235-250
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• 2017

In this study, we monitored 4 volatile organic compounds (VOCs) such as chloroform, dichloromethane, 1,2-dichloroethane, and tetrachloromethane in groundwater samples to determine the detection frequency and their concentrations and evaluated the health risk level considering ingestion, inhalation, and skin contact. 75 groundwater wells were selected. 24 wells were from monitoring background groundwater quality level and 51 wells were from monitoring groundwater quality level in industrial or contamination source area. In the results, the detection frequency for chloroform, dichloromethane, 1,2-dichloroethane, and tetrachloromethane was 42.3%, 8.1%, 6.0%, and 3.4%, respectively. The average concentrations of VOCs were high in the order of chloroform ($1.7{\mu}g\;L^{-1}$), dichloromethane ($0.08{\mu}g\;L^{-1}$), tetrachloromethane ($0.05{\mu}g\;L^{-1}$), and 1,2-dichloroethane ($0.05{\mu}g\;L^{-1}$). Chloroform had the highest detection frequency and average detection concentration. In the contaminated groundwater, the detection frequency of VOCs was high in the order of chloroform, dichloromethane, 1,2-dchloroethane, and tetrachloromethane. The average concentrations for chloroform, dichloromethane, 1,2-dichloroethane, and tetrachloromethane were $2.23{\mu}g\;L^{-1}$, $0.08{\mu}g\;L^{-1}$, $0.07{\mu}g\;L^{-1}$, and $0.06{\mu}g\;L^{-1}$, respectively. All the 4 compounds were detected at industrial complex and storage tank area. The maximum concentration of chloroform, dichloromethane, and 1,2-dichloroethane was detected at industrial complex area. Especially, the maximum concentration of chloroform and dichloromethane was detected at a chemical factory area. In the uncontaminated groundwater, the detection frequency of VOCs was high in the order of chloroform, dichloromethane, and 1,2-dchloroethane and tetrachloromethane was not detected. The average concentrations for chloroform, dichloromethane, and 1,2-dichloroethane were $0.57{\mu}g\;L^{-1}$, $0.07{\mu}g\;L^{-1}$, and $0.03{\mu}g\;L^{-1}$, respectively. Although chloroform in the uncontaminated groundwater was detected the most, the concentration of chloroform was not exceeding water quality standards. By land use, the maximum detection frequency of 1,2-dichloroethane was found near a traffic area. For human risk assessment, the cancer risk for the 4 VOCs was $10^{-6}{\sim}10^{-9}$, while the non-cancer risk (HQ value) for the 4 VOCs is $10^{-2}{\sim}10^{-3}$.

• Korean Journal of Ecology and Environment
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• v.38 no.2 s.112
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• pp.137-145
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• 2005

Traditional screening techniques have missed up to 99% of microbial resources existing in the nature. Strategies of direct cloning of environmental DNAs comprising tine genetic blueprints of entire microbial metagenomes provide vastly more genetic information than is contained in the culturable. Therefore, one way to screening the useful gene in a variety of environments is the construction of metagenomic DNA library. In this study, the water samples were collected from Daecheong Reservoir in the mid Korea, and analyzed by T-RFLP to examine the diversity of the microbial communities. The crude DNAs were extracted by SDS-based freezing-thawing method and then further purified using an $UltraClean^{TM}kit$ (MoBio, USA). The metagenomic libraries were constructed with the DNAs partially digested with EcoRI, BamHI, and SacII in Escherichia coli DH10B using the pBACe3.6 vector. About 14.0 Mb of metagenomic libraries were obtained with average inserts 13 ${\sim}$ 15 kb in size. The genes responsible for degradation of 1, 2-dichloroethane (1, 2-DCE) via hydrolytic dehalogenation were identified from the metagenomic libraries by colony hybridization. The 1, 2-dichloroethane dehalogenase gene (dhlA) was cloned and its nucleotide sequence was analyzed. The activity of the 1, 2-DCE dehalogenase was highly expressed to the substrate. These results indicated that the dhlA gene identified from the metagenomes derived from Deacheong Reservoir might be useful to develop a potent strain for degradation of 1, 2-DCE.

• YAKHAK HOEJI
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• v.45 no.1
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• pp.34-38
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• 2001

The Phellodendri Cortex of Phellodendron amurense (Rutaceae) is known to contain a number of isoquinoline alkaloid, and berberine, palmatine, jateorrhizine, phellodendrine and magnoflorine are the major constituents of protoberberine alkaloids. For the determination of protoberberine alkaloids from Phellodendri Cortex and berberine chloride from the preparation, the new spectrophotometric method was developed with a simple and selective sample clean-up using thiocyanatocobaltate[II] complex ion. Samples were extracted with 0.1 mM hydrochloric acid, potassium biphthalate reagent, thiocyanatocobaltate reagent and 1.2-dichloroethane for 60 min. The absorbance of protoberberine alkaloid complexes in 1.2-dichloroethane solution was measured at 625 nm. Calibration curve for berberine was linear over the concentration range of 0.05~0.30 mg/ml 1.2-dichloroethane. The method proved to be rapid, simple and reliable for the determination of protoberberine alkaloids from Phellodendri Cortex and berberine chloride from the preparation.

• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.169-176
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• 2011

The electrochemical investigation of N,N-bis (2,5-di-tert-butylphenyl)-3,4,9,10 perylenebis (dicarboximide) laser dye have been carried out using cyclic voltammetry and convolution - deconvolution voltammetry combined with digital simulation technique at a platinum electrode in 0.1 mol/L tetrabutyl ammonium perchlorate (TBAP) in solvent 1,2 dichloroethane ($CH_2Cl-CH_2Cl$). The investigated dye was reduced via consumption of two sequential electrons to form radical anion and dianion (EE mechanism). In switching the potential to positive scan, the compound was oxidized by loss of two electrons, which were followed by a fast aggregation process ($EC_1EC_2$ mechanism). The electrode reaction pathway and the chemical and electrochemical parameters of the investigated compound were determined using cyclic voltammetry and convolutive voltammetry. The extracted electrochemical parameters were verified and confirmed via digital simulation method.

• Bulletin of the Korean Chemical Society
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• v.16 no.6
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• pp.479-483
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• 1995

The synergistic extraction of palladium(Ⅱ) was studied with 1,2-dichloroethane containing thenoyltrifluoroacetone (TTA; HA) and tri-n-octylphosphine oxide (TOPO; S). The main composition of synergistic adduct extracted into 1,2-dichloroethane phase was found to be PdA2S2. The equilibrium constants of the synergistic reaction were calculated. The application of this method to synthetic mixture for the separation of Pd from Pt was developed.

• Membrane Journal
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• v.14 no.2
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• pp.157-165
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• 2004

PU/PDMS(Poly urethane/poly(dimethylsiloxane ) membranes were prepared to enhance chemical resistance over VOCs from 4,4'-diphenylmethane diisocyanate (MDI), poly(dimethylsiloxane) (PDHS). Swelling characteristics and vapor permeation performance of toluene, 1,2-dichloroethane, hexane through PU/PDMS membrane with various feed VOCs concentration were investigated. Swelling ratio of VOCs showed tendency of Toluene > 1,2-dichloroethane > hexane. Fiux of toluene and 1,2-dichloroethane increased with increasing fled concentration while the flux of hexane maintained with increasing feed. VOCs concentration in permeate maintained 50 wt% oi concentration due to high affinity of PU/PDHS membranes to VOCs.

• Journal of the Korean Society of Safety
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• v.14 no.2
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• pp.103-108
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• 1999

This study focused on risk assessment for inhalation of airborne volatile organic compounds (VOCs) in Ulsan industrial complex area. For non-carcinogenic risk, even the highest hazard index of toluene was estimated to be $4.8\times10^{-2}$, which was much lower than 1. The total hazard index of VOCs was estimated to be $5.8\times10^{-2}$. However, lifetime average cancer risk from the inhalation of airborne VOCs was estimated to be about $1.1\times10^{-3}/$, which was much higher than a risk standard of $10^{-5}$. The risk of $4.4\times10^{-5}$. came from benzene, the only human carcinogen among VOCs, while that of $1.05\times10^{-3}$ from probable human carcinogens including 1,3-butadiene and 1,2-dichloroethane. About 70% and 20% of total VOC cancer risk was due to the inhalation of 1,3-butadiene and 1,2-dichloroethane, respectively. Therefore, proper risk management of these 3 VOCs was required for the protection of health from cancer burden in Ulsan industrial complex area.