백우현 교수 정년퇴임 기념호

학회자료 한국환경과학회 2006 한국환경과학회지 Vol.15 No.3

은이온 교환 A형 제오라이트로 부터의 은이온용출이 항균력에 미치는 영향

이무강,신현무,임경천 한국환경과학회 2004 한국환경과학회지 Vol.13 No.1

An author has been known that A-type zeolite supported with silver ions has excellent antibacterial activity. However, it is no research of concern in the antibacterial activity of eluted silver ions. This study tested the elution of silver ions from A-type zeolite silver ions in deionized distilled water and NaNO₃ aqueous solution. In NaNO₃ aqueous solution of 74mM to 588mM, it was found that the concentration of silver ions and electric conductivity increased with the increasing concentration of sodium ions, and equilibrated at 15 min, and the ion exchange equilibrium coefficient, k, is 1.3x 10^(-3). However, deionized distilled water is not equilibrated to pass 6 months. A-type zeolite sodium ions showed no antibacterial activity. It was found that antibacterial activity was exhibited even at the concentration of 10 nM of eluted silver ions, and E-coli died with the incorporation of 2.43 × 10^(8) Ag ion/cell. antibacterial activity of A-type zeolite silver ions were mainly attributed to hydroxyl radical.

고체 촉매를 이용한 대두유와 폐식용유의 에스테르화

신용섭 한국환경과학회 2004 한국환경과학회지 Vol.13 No.1

Esterification of soybean oil with methanol was investigated. First of all, liquid-liquid equilibriums for systems of soybean oil and methanol were measured at temperatures ranging from 40 to 65°C. Profiles of conversion of soybean oil with time were determined from the glycerine content in reaction mixtures for the different kinds of catalysts, such as NaOH, CaO, Ca(OH)₂, MgO, Mg(OH)₂, and Ba(OH)₂. The effects of dose of catalyst, cosolvent and reaction temperature on final conversion were examined. Esterification of waste vegetable oil with methanol was investigated and compared to the case of soybean oil. Solubility of methanol in soybean oil was substantially greater than that of soybean oil in methanol. When the esterification reaction of soybean oil was catalyzed by solid catalyst, final conversion was strongly dependent on the alkalinity of the solid catalyst, and increased with the alkalinity of the metal. Hydroxides from the alkali metals were more effective than oxides. When Ca(OH)₂ was used for the esterification catalyst, maximum value of final conversion was measured at dose of 4%. When CHCl₃ as a cosolvent, was added into the reaction mixture of soybean oil which catalyzed by Ba(OH)₂, maximum value of final conversion was appeared at dose of 3%. When waste vegetable oil was catalyzed by NaOH and solid catalysts, high final conversion, over 90%, and fast reaction rate were obtained.

황산염을 이용한 매립지 유기물분해 촉진과 분해속도에 관한 연구

김정권,윤태경,김가야 한국환경과학회 2004 한국환경과학회지 Vol.13 No.1

In this study, sulfate reduction reaction was used to increase the decomposition of organics, which is the most critical factor for the stabilization of a landfill site. Composite of sewage sludge, papers, and incineration ashes was used in the column. The experimental results indicated that out of 10 reactors, the reactors 3, 4, 8, and 9 showed higher organics (i.e., TOC) removal rate than that in the absence of sulfate. The organics removal rates (K) in R3 and R9 were 8.65e^(-4)/d and 3.82e^(-4)/d, respectively. The times to reach 10% of initial concentrations in R3 and R9 was 7.3 and 16.5 years, respectively, showing faster organics decomposition rates in these reactors.

Cu, Pb, 및 Cd로 오염된 토양의 동전기적 방법에 의한 제거에 있어 중금속 종이 미치는 영향

신현무,윤삼석 한국환경과학회 2004 한국환경과학회지 Vol.13 No.1

Three kinds of toxic heavy metals, such as lead, copper, and cadmium, existing abundantly in contaminated soils were selected to investigate pH change, electroosmotic flow, and the removal rate in the application of electrokinetic process. In the change of pHs, they reached to about 12 and 2 at each cathodic and anodic region, respectively, and maintained for reaction being proceeded. Electroosmotic flow rates were not influenced by the kind of metal species but by electropotential gradient. On the soils contaminated by each metal, the removal rate of Cd was the fastest among three as in the order of Cd>Pb>Cu. While on the soils contaminated by mixed metal species, Cu was the fastest. Metal species transported by electrokinetic processes were distributed in between 0.9 and 1.0 of normalized region. In the case of soils contaminated by one kind of metal. the relative concentrations of Pb and Cd estimated in between normalized region 0.9 and 1.0 were 5.2 and 5.7, respectively.

정수처리공정상 염소소독부산물형성에 미치는 오존의 영향

성낙창,박현석,이성식,이용희,이종팔,윤태경 한국환경과학회 2004 한국환경과학회지 Vol.13 No.1

The effect of ozone on the formation and the removal of disinfection byproducts(DBPs) of chlorination process was studied to elucidate the performance of water treatment process. The samples of raw water, prechlorination process, and preozonation process were analyzed quantitatively according to the Standard Methods for the Examination of drinking water. As a result, most of total trihalomethanes(THMs) which were formed in prechlorine treatment process was not removed in the preozonation process. Most of haloacetic acids(HAAs), haloacetonitriles(HANs), and chloral hydrate(CH) was removed in sedimentation and biological activated carbon(BAC) filtration processes. However, DBPs were increased more or less by postchlorine step. In particular, the formation of THMs and HAAs depends on ozone more than chlorine, but, the formation of HANs and CH depends on chlorine more than ozone. The seasonal variation of DBPs concentration for the year needs to be investigated to study the temperature effect because DBPs strongly depend on temperature among various efficient factors.

활성탄/플리우레탄 복합담체를 충전한 바이오필터에서 H₂S의 제거특성

감상규,강경호,임진관,이민규 한국환경과학회 2004 한국환경과학회지 Vol.13 No.1

A biofiltration system using activated carbon/polyurethane composite as solid support inoculated with Bacillus sp. was developed for treating a gaseous stream containing high concentrations of H₂S. The effects of operating condition such as the influent H₂S concentration and the empty bed contact time (EBCT) on the removal efficiency of H₂S were investigated. The biofilter showed the stable removal efficiencies of over 99 % under the EBCT range from 15 to 60 sec at the 300 ppmv of H₂S inlet concentration. When the inlet concentration of H₂S was increased, the removal efficiencies decreased, reaching 95 and 74%, at EBCTs of 10 and 7.5 sec, respectively. The maximum elimination capacity in the biofilter packed with activated carbon/polyurethane composite media was 157 g/m³/hr.

광산화-활성탄 복합공정에 의한 B.T.X. 분해에 관한 연구

정창훈,배해룡 한국환경과학회 2004 한국환경과학회지 Vol.13 No.1

In this study, The decomposition of gas-phase Benzene and Toluene, Xylene in air streams by direct UV Photolysis, UV/TiO2 and UV/TiO₂/A.0 process was studied. The experiments were carried out under various UV light intensities and initial concentrations of B.T.X to investigate and compare the removal efficiency of the pollutant. B.T.X was determined by GC-FID of gas samples taken from the a glass sampling bulb which was located at reactor inlet and outlet by gas-tight syringe. From this study, the results indicate that UV/TiO₂/A.C system (photooxidation-photocatalytic oxidation-adsorption process) is ideal for treatment of B.T.X from the small workplace. Although the results needs more verifications, the methodology seems to be reasonable and can be applied for various workplace (laundry, gas station et al.).

광산화 및 광촉매 공정에서 VOCs의 산화반응 속도 산출에 관한 연구

정창훈,이경호 한국환경과학회 2004 한국환경과학회지 Vol.13 No.1

In this study, the decomposition of gas-phase TCE, Benzene and Toluene, in air streams by direct UV Photolysis and UV/TiO₂ process was studied. For direct UV Photolysis, by regressing with computer calculation to the experimental results the value of reaction rate constant k of TCE, Toluene and Benzene in this work were determined to be 0.00392s^(-1), 0.00230s^(-1) and 0.00126s^(-1), respectively. And the adsorption constant K of TCE, Toluene and Benzene in this work were determined to be 0.0519mo1^(-1) ,0.0313mo1^(-1) and 0.0084mo1^(-1), respectively. For W/TiO₂ system by regressing with computer calculation to the experimental results the value of reaction rate constant k of TCE, Toluene, and Benzene in this work were determined to be 5.74g/ℓ · min, 3.85g/ℓ · min, and 1.18g/ℓ · min, respectively. And the catalyst adsorption constant K of TCE, Toluene, and Benzene in this work were determined to be 0.0005m³/㎎, 0.0043m³/㎎ and 0.0048m³/㎎, respectively.

물 및 토양 중 유기염소계 농약의 분석

김정호 한국환경과학회 2003 한국환경과학회지 Vol.12 No.12

To obtain the residual orhanochlorine pesticides in the coastal enviroment, the methods of analysis for BHC's isomer, Kelthane, Orthocide and Endrin by GC-ECD are surveyed. The relative retention time for α-BHC, β-BHC, γ-BHC and δ-BHC is 1.00, 1.18, 1.24, 1.31 and it's of Kelthane, Orthocide, Endrin is 1.56, 1.70, and 2.02, respectively. The BHC isomers, Kelthane, Orthocide and Endrin are separated on the base line. The plate height(H) for α-BHC, β-BHC, γ-BHC and δ-BHC is 50㎜, 35㎜, 32㎜ and 29㎜, and it's of Kelthane, Orthocide, Endrin is 81㎜, 68㎜ and 48㎜, respectively. The qualified defection concentration for α-BHC, β-BHC, γ-BHC and δ-BHC is 0.26, 0.36, 0.37 and 0.39ng/g and it's of Kelthane, Orthocide, Endrion is 0.55, 1.39 and 0.56ng/g, respectively. BHC's isomer, Kelthane, Orthocide and Endrion are not detected in soil environment on South Cheju Island. Also residual organochlorine pesticides are not detected in the sea water and sediment in the ocean environment.