• 상하수도학회지
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• 제21권4호
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• pp.375-383
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• 2007

Treatment efficiency research was performed using Fenton process and the electrochemical process in the presence of ferrous ion and hydrogen peroxide for the industrial wastewater including 1,4-Dioxane produced during polymerization of polyester. The Fenton process and the electrochemical Iron Redox Reaction (IRR) process were applied for this research to use hydroxyl radical as the powerful oxidant which is continuously produced during the redox reaction with iron ion and hydrogen peroxide. The results of $COD_{Cr}$ and the concentration of 1,4-Dioxane were compared with time interval during the both processes. The rapid removal efficiency was obtained for Fenton process whereas the slow removal efficiency was occurred for the electrochemical IRR process. The removal efficiency of $COD_{Cr}$ for 310 minutes was 84% in the electrochemical IRR process with 1,000 mg/L of iron ion concentration, whereas it was 91% with 2,000 mg/L of iron ion concentration. The lap time to remove all of 1,4-Dioxane, 330 mg/L in the wastewater took 150 minutes with 1,000 mg/L of iron ion concentration, however it took 120 minutes with 2,000 mg/L of iron ion concentration in the electrochemical IRR process.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권2호
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• pp.79-85
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• 2001

A conventional electrolyzing cell has been made by an ion exchange membrane inbetween parallel plate electrodes. A low dc voltage is applied to the electrodes for electrolyzing and the efficiency is remained in low. in this study, a novel electrolyzing cell with a pair of slit-type third electrodes installed inbetween parallel plate electrodes has been proposed and investigated experimentally. And pulse power wa supplied to between each electrodes. This slit type of third electrodes can concentrate the strong electric fields at the every its edges to accelerate the electrolyzing powers, and to generate oxygen bubble discharges for generating oxidants. And moreover the slits eliminate the space charge limiting action and the temperature of the water by leaking out through the slits from electrolyzing region to outside of the main electrode region. As a result, it was found that a strong electorzed water of pH 2.8 and pH 10.5 and oxidants dissolved water of 1 [ppm] in acidic water were obtained with a tap water fed at the electric current of 2 [A], which however were several times higher oxidant and ion concentration quantity compared with the conventional cell.

• 상하수도학회지
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• 제32권2호
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• pp.145-152
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• 2018

This study is focused on manganese (Mn(II)) removal by ozonation in surface water. Instant ozone demand for the water was 0.5 mg/L in the study. When 0.5 mg/L of Mn(II) is existed in water, the optimum ozone concentration was 1.25 mg/L with reaction time 10 minutes to meet the drinking water regulation. The ozone concentration to meet the drinking water regulation was much higher than the stoichiometric concentration. The reaction of soluble manganese removal was so fast that the reaction time does not affect the removal dramatically. When Mn(II) is existed with Fe, the removal of Mn(II) was not affected by Fe ion. However As(V) is existed as co-ion the removal of Mn(II) was decreased by 10%. Adding ozone to surface water has limited effect to remove dissolved organic matter. When ozone is used as oxidant to remove Mn(II) in the water, the existing co-ion should be evaluated to determine optimum concentration.

• 한국자원식물학회지
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• 제29권5호
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• pp.588-597
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• 2016

Little attention has been paid to the functional aspect of the flower petal of Paeonia lactiflora, compared to that of its root. To determine the components of flower petal of Paeonia lactiflora, we conducted the Fourier transform ion cyclotron resonance (FT-ICR) MASS spectrophotometric analysis. We detected the 24 different types of ingredients from the 70% ethanol extracts of flower petal of peonia lactiflora cv. ‘Red Charm’. The main compounds were quercetin glucopyranosides, methyl gallate, paonioflolol and kaemperol glucopyranosides. We further tested its functional activity. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the extracts was 87.9-90.4% at 0.1mg/ml. This result showed that these flower extracts have approximately 5-fold stronger antioxidant potential than a previous report with root extracts (Bang et al. 1999). The result of tyrosinase inhibition assay of Paeonia lactflora extract was almost similar to that of arbutin except significantly higher effect in the coral sunset extract at 0.1% concentration. Hyaluronidase inhibition assay showed 76.5% inhibition at 5% concentration of this flower extract, indicating that Peaonia lactiflora flower extracts have the major anti-inflammatory, anti-oxidant and brightening effects. Taken together, these results suggest these three Paeonia lactiflora species extracts might provide the basis to develop a new natural brightening agent.

• 한국포장학회지
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• 제28권3호
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• pp.165-170
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• 2022

최근 지구온난화 심화와 환경재난 등으로 석유유래 플라스틱의 분해에 대한 관심이 높아지고 있다. 플라스틱의 분해를 촉진하는 산화촉진제로 ferric ion(Fe²⁺)을 농도별로 첨가하여 필름을 제조하였다. 대조군으로 LLDPE필름과 산화촉진제를 농도별로 첨가한 필름에 UV를 시간별로 조사하여 인장강도, 신장율과 분자량변화를 조사하였다. 수지에 ferric ion 첨가량이 많아질수록 물성저하가 컸으며, 분자량 변화도 큰 것으로 나타났다. 인장강도는 대조군에 비해 산화촉진제 첨가필름이 조사시간 100시간 후 부터는 현저하게 저하되었으며, 이러한 현상은 신장율에서도 비슷한 것으로 나타났다. 분자량은 산화촉진제 첨가에 따른 결과로 UV 조사 50시간 후 63.6%, 100시간 후에는 73.8% 분자량이 감소한 것으로 나타났다. 이상의 결과에서 플라스틱 필름에 산화촉진제인 ferric ion(Fe²⁺)을 첨가함에 따라서 필름의 강도와 분자량이 저하되는 결과와 김 등 등의 보고를 바탕으로 필름의 분자량이 저하되면 그만큼 필름이 분해되고 있다고 판단할 수 있을 것으로 사료되었다.

• Environmental Engineering Research
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• 제10권5호
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• pp.205-212
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• 2005

The study was conducted to investigate the removal of heavy metals by using Hydroxyapatite(HAp) made from waste oyster shells and wastewater with high concentration of phosphorus. The maximum calcium concentration for the production of HAp in this study was released up to 361 mg/L at pH of 3 by elution experiments. When the pH was at adjusted 6, the maximum calcium released concentration was 41 mg/L. During the elution experiment, most of the calcium was released within 60 minutes. This reaction occurred at both pH levels of 3 and 6. The result of the XRD analysis for the HAp product used in this study shows the main constituent was HAp, as well as OCP. The pH was 8.6. As the temperature increased, the main constituent did not vary, however its structure was crystallized. When the pH was maintained at 3, the removal efficiency decreased as the heavy metal concentration increased. The order of removal efficiency was as follows: $Fe^{2+}$(92%), $Pb^{2+}$(92%) > $Cu^{2+}$(20%) > $Cd^{2+}$(0%). Most of these products were dissolved and did not produce sludge in the course of heavy metals removal. As the heavy metal concentration increased at pH of 6, the removal efficiency increased. The removal efficiencies in all heavy metals were over 80%. From the analysis of the sludge after reaction with heavy metals, the HAp was detected and the OCP peak was not observed. Moreover, lead ion was observed at the peaks of lead-Apatite and lead oxidant. In the case of cadmium, copper and iron ions, hydroxide forms of each ion were also detected.

• 한국응용과학기술학회지
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• 제29권4호
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• pp.570-576
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• 2012

본 연구에서는 무격막식 전기분해 처리된 해수를 산화제로하는 NO 산화반응의 특성에 대해 실험적으로 살펴보았다. 폐순환 정전류 전기분해 시스템을 통해전해 시간이 길어질수록 전해수의 유효 염소농도와 온도, 염소산 이온의 비율이 증가함을 확인하였다. 전해수가 채워진 버블링 반응기에서 전해수의 유효염소농도와 온도에 비례하여 $NO_2$로 산화되는 NO의 양이 증가하였다. 또한 산화되어 생성된 $NO_2$는 전해수에 용해되어 $HNO_3{^-}$ 이온으로 존재함을 확인하였다.

• 대한약침학회지
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• 제2권1호
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• pp.13-25
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• 1999

This study was undertaken to determine whether Juglandis Semen (JAS) extraction exerts protective effect against oxidant-induced inhibition of $Na^+$-pump activity in cerebral cortex. $Na^+$-pump activity was estimated by measuring ouabain-sensitive oxygen consumption. The oxygen consumption significantly inhibited by 1 mM t-butylhydroperoxide (tBHP), which was prevented by addition of 2% JAS extraction. The oxygen consumption was increased by an increase in $Na^+$ concentration from 5 to 100mM, $K^+$ concentration from 0.5 to 10 mM, and $Mg^{++}$ concentration from 0.2 to 5 mM. These changes in ion concentrations did not affect the inhibitory effct of tBHP and protective action of JAS on oxygen consumption. tBHP(1mM) produced a significant increase in lipid peroxidation in cerebral cortex, which was prevented by 2% JAS extraction. These result suggest that JAS exerts protective effect against tBHP-induced inhibition of $Na^+$-pump activity in the cerebral cortex, this effect may be due to by an antioxidant action.

• 상하수도학회지
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• 제9권4호
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• pp.87-96
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• 1995

The Electron/Hole Pair is generated when the activation energy produced by ultraviolet ray illuminates to the semiconductor and OH- ion produced by water photocleavage reacts with positive Hole. As a results, OH radical acting as strong oxidant is generated and then Photocatalytic oxidation reaction occurs. The photocatalytic oxidation can oxidate the non-degradable and hazardous organic substances such as pesticides and aromatic materials easier, safer and shorter than conventional water treatment process. So in this study, many factors influencing the oxidation of chlorophenols, such as inorganic electrolytes addition, change of oxygen and nitrogen atmosphere, temperature, pH, oxygen concentration, chlorophenol concentration, were throughly examined. According to the experiments observations, it is founded that the rate of chlorophenol oxidation follows a first-order reaction and the modified Langmuir-Hinshelwood relationship. And the photocatalytic oxidation occurs only when activation energy acting as Electron/Hole generation, oxygen acting as electron acceptor to prevent Electron/Hole recombination, $TiO_2$ powder acting as photocatalyst are present. The effects of variation of dissolved oxygen concentration, temperature and inorganic electrolytes concentration on 2-chlorophenol oxidation are negligible. And the lower the organic concentration, the higher the oxidation efficiency becomes. Therefore, the photocatalytic oxidation is much effective to oxidation of hazardous substances at very low concentration. The oxidation is effective in the range of 0.1 g/L-10 g/L of $TiO_2$. Finally when the ultra-violet ray is illuminated to $TiO_2$, the surface characteristics of $TiO_2$ change and Adsorption/Desorption reaction on $TiO_2$ surface occurs.

• 상하수도학회지
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• 제24권3호
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• pp.341-349
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• 2010

It is well known that manganese is hard to oxidize under neutral pH condition in the atmosphere while iron can be easily oxidized to insoluble iron oxide. The purpose of this study is to identify removal mechanism of manganese in the D water treatment plant where is treating bank filtered water in aeration and rapid sand filtration. Average concentration of iron and manganese in bank filtered water were 5.9 mg/L and 3.6 mg/L in 2008, respectively. However, their concentration in rapid sand filtrate were only 0.11 mg/L and 0.03 mg/L, respectively. Most of the sand was coated with black colored manganese oxide except surface layer. According to EDX analysis of sand which was collected in different depth of sand filter, the content of i ron in the upper part sand was relatively higher than that in the lower part. while manganese content increased with a depth. The presence of iron and manganese oxidizing bacteria have been identified in sand of rapid sand filtration. It is supposed that these bacteria contributed some to remove iron and manganese in rapid sand filter. In conclusion, manganese has been simultaneously removed by physicochemical reaction and biological reaction. However, it is considered that the former reaction is dominant than the latter. That is, Mn(II) ion is rapidly adsorbed on ${\gamma}$-FeOOH which is intermediate iron oxidant and then adsorbed Mn(II) ion is oxidized to insoluble manganese oxide. In addition, manganese oxidation is accelerated by autocatalytic reaction of manganese oxide. The iron and manganese oxides deposited on the surface of the sand and then are aged with coating sand surface.