• Membrane and Water Treatment
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• 제1권1호
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• pp.1-12
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• 2010

Membrane distillation process was used for purification of pre-treated natural water (tap water). The rejection of inorganic and organic compounds in this process was investigated. The obtained rejection of inorganic solutes was closed to 100%, but the volatile organic compounds (VOCs) diffused through the membrane together with water vapour. The content of trihalomethanes (THMs) in the obtained distillate was two-three fold higher than that in the feed, therefore, the rejection of the total organic compounds present in the tap water was reduced to a level of 98%. The intensive membranes scaling was observed during the water separation. The morphology and composition of the fouling layer was studied using scanning electron microscopy coupled with energy dispersion spectrometry. The influence of thermal water pre-treatment performed in a heat exchanger followed by filtration on the MD process effectiveness was evaluated. This procedure caused that significantly smaller amounts of $CaCO_3$ crystallites were deposited on the membrane surface, and a high permeate flux was maintained over a period of 160 h.

• 한국산업융합학회 논문집
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• 제7권3호
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• pp.289-297
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• 2004

Emissions of volatile organic compounds and odors from various industrial processes not only pollute surrounding life environments, but also lead to the deterioration of the working environments, causing various industrial health and business problems. These pollutants are usually stimulating, irritating, malodorous and sometimes carcinogenic, Which should be reduced in the pollutants formation, stage, but the practical processes do not allow This paper describes the major sources of VOC and odors, and their sampling/analysis methods. Furthermore, various removal technologies for these pollutants are suggested, which particularly include the characteristics of the catalytic and scrubber/carbon filter combined process, and even process design technologies.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.517-520
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• 2001

Fossil fuels such as coal and crude oil contain various organic sulfur compounds. Combustion of these fuels emit sulfur oxides which are considered as msjor air pollutants causing acid rain problem. Among various organic sulfur compounds, aromatic sulfur compounds of thiophenes which constitute major sulfur fractions of heavy oils are not easily removed by hydrodesulfurization. Many peroxidase and hemoproteins are known to oxidize dibenzothiophene (DBT) to dibenzothiophene-sulfoxide(DBT - sulfoxide) then dibenzothiophene- sulfone (DBT-sulfone). The oxidation of DBT by the immobilized hemoproteins in n-octane was increased significantly when the hemoproteins were deposited on celites of the particle size between 0.75 - 1.0 mm and a conventional substrates. such as t-butyl hydroperoxide and cumene hydroperoxide. In anhydrous organic solvents with log P values larger than 4.0 DBT was completely oxidized by cumene hydroperoxide catalyzed by cytochrome c deposited on celites.

• 미생물과산업
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• 제20권3호
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• pp.70-73
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• 1994

Effects of 13 organic compounds including glucose, fructose, xylose, glutamate, succinate, malate, glycine, lactate, acetate, pyruvate, citrate, formate and cis-aconitate on the oxidation of thiosulfate and the availability of these compounds as the substrate for the respiration by Thiobacillus ocncretivorus, which is known to be an obligated autotroph, were studied. Malate nad glycine at 0.5 per cent concentration nearly doubled the thiosulfate oxidation compared to the control. No other organic substances enhanced the thiosulfate oxidation compared to the control. No other organic substances enhanced the thiosulfate oxidation. Moreover, some 30 to 40 per cent decrease was recorded by fructose, sulfate-salts medium, some 30 to 40 per cent decrease was recorded by fructose, citrate, xylose, malate, flucose, glutamate and succinate. No respiration could occur when formate and pyruvate were supplied as the substrate for respiration. But it was obvious that flucose, fructose, xylose, glutamate, malate, citrate and succinate could be used as the substrate for respiration to some extent, regarding the fact that some increase in respiration rates could be recorded compared to the result from the salts medium, where neither thiosulfate nor orgnic compounds were added. Thus, it was postulated that this organism could possibly be converted into mixotroph or hetrotroph if appropriate conditions could be prepared.

• 한국주거학회논문집
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• 제13권5호
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• pp.71-76
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• 2002

Recently, much attention has been paid to the problem such as sick building syndrome, which caused by the air pollutant indoor. In addition, Volatile Organic Compounds(VOCs) has been paid attention to as one of the main reason that causes air pollutant indoor, and the exposure of VOCs indoor is recognizes as an important factor which have an effect on the health of resident. In this study, measuring of VOCs in newly houses, and the results are as follows; 1)TVOC(Total Volatile Organic Compounds) indoor is detected high concentration(11314$\mu\textrm{g}$/㎤). 2)There are detected acetaldehyde, methylenechloride, benzene, trichloroethylene and styrene that have to take precaution against human carcinogenicity

• 한국환경과학회지
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• 제12권7호
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• pp.825-833
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• 2003

The emission of volatile organic compounds (VOCs) generated from painting and coating processes is a worldwide problem as contributing factors to the development of photochemical smog and other environmental problems. Common methods of reducing VOC emissions are adsorption on activated carbon, membrane separation, absorption, incineration, or catalytic oxidation. In this article, the environmental issues caused by VOC emissions and the trend of legislation against such emissions will be surveyed first. Several conventional control technologies will then be summarized and the characteristics of each process will be introduced. Lastly, some examples will be described to show the hybrid processes which have been industrially applied for the recovery of VOC.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.162-163
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• 2003

수소를 생산하는 암반응에서는 pH와 dry cell weight, 세포내의 starch 함유량이 시간에 따라 줄어들었다. 유기물은 시간에 따라 증가하였지만, 수소는 3일째에 생산이 최대치에 도달하였다.

• 한국대기환경학회지
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• 제13권3호
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• pp.221-229
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• 1997

Wax is a protectant for floors that is used widely in Korea and is considered an emission source of volatile organic compounds (VOCs) in the indoor environment. This study examined the concentration change of indoor VOCs due to waxing and also due to wiping the floor with an oiled dustcloth. VOCs were identified using a cryogenic concentration/thermal desorption system with capillary GC that utilized a liquid nitrogen cryostat and induction heating. The major components emitted from the waxing were nonane, decane, undecane, $C_2$-benzene, and $C_3$-benzene. The concentrations of nonane were 1,276 $\mu\textrm{g}$/㎥ an hour after wax applications, 832 $\mu\textrm{g}$/㎥ after 3 days, and less than 10$\mu\textrm{g}$/㎥) after 15 days. Another emission source of VOCs in indoor was the oiled dustcloth used for cleaning the floor. The oiled dustcloth gave VOCs concentrations three times higher than the normal undusted floor.

• 한국환경과학회지
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• 제7권1호
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• pp.104-111
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• 1998

The Dongbok lake water before and after alum coagulation and activated carbon adsorption were analyzed in terms of organic contents, molecular weight distributuin (MWD), and UV-absorbance. Dissolved organic compounds in the Dongbok lake were fractionated into three molecular size classes by gel permeation chromatography. The fractionation was reasonably successful in isolating compounds with The bulk of the dissolved carbon was present in compounds of molecular weight in the range of 3,000~10,000. Alum coagulation preferentially treated molecules of high molecular weight, which has molecules larger than 10,000. The dissolved organic carbon (DOC) removal after activated carbon adsorption was high in the Fraction B , IR . The $A_{260}$/DOC ratio after alum and activated carbon treatment the Fraction II, III. This results suggest that the organics remaining after each treatment has a trihalomethane formation potential

• 한국대기환경학회지
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• 제14권1호
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• pp.73-77
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• 1998

In this study, a total of 10 volatile organic compounds (VOCs) including BTEX were determined in the inside and outside of a highway thnnel in order to evaluate the emission profile of automobile exhaust with respect to the concentrations, relative ratio and correlation coefficient of target analytes. In addition to VOCs, CO $CO_2 and NO_2$ were measured simultaneously. The results of this study indicated that the most abundant compound was toluene followed by benzene and m+p-xylenes, and the correlation coefficients between VOCs except styrene were higher than 0.96. The concentration ratio of toluene, ethylbenzene, xylenes with respect to benzene measured in the inside of tunnel was 1.5, 0.13, 0.74, respectively. Such ratios were found to be very similar to those measured in tunnels in the USA.