• Title/Summary/Keyword: Oxidation/Reduction Potential

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A study on Establishment of Vermicomposting Index Using Leakage Water (침출액을 이용한 지렁이 퇴비화지표 설정에 관한 연구)

  • Lee, Chang-Ho;Kim, Jong-Oh;Choi, Suk Soon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.15 no.1
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    • pp.178-184
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    • 2007
  • In the present work, the vermicomposting index was investigated using leakage water from sludge to develop the process of mechanization and automation in the earthworm-cast treatment. The in situ sewage sludge was used batch and continuous experiments. Due to different treatment processes, the physico-chemical characteristics of liquid extracted from sludge was the similar change pattern. However, some items, such as Oxidation Reduction Potential (ORP), pH, Electrical Conductivity (EC) and $NH_3-N$, showed the distinct changes between pre- and post-vermicomposting. Also, The ORP and EC were the best parameters for the vermicomposting index. These results offered that the present vermicomposting technology was an actual earthworm-cast treatment.

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Environmental Contamination from Acid Mine Drainage (산성광산배수로 인한 환경오염도 조사)

  • Kang, Mee-A
    • The Journal of Engineering Geology
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    • v.17 no.1 s.50
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    • pp.143-150
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    • 2007
  • AMD (Acid mine drainage) from disused mines is one or the most significant pollutant problems to make harmful effect to human health. We demonstrated the mechanism of resolution and adsorption reaction for arsenic, manganese and zink from the soil and mine tailings which were located in the vicinity of a disused mine in Kyoungnam area. The resolution experiments were carried with a column test f3r 45 days continuously. Metal chemical forms in water were changed with the condition of solution pH and ORP (oxidation-reduction potential). Metal chemical forms affected on the reaction of resolution and adsorption of metals in water environments. Even though the sampling was carried in very closed location, there was significant different results of pollution level and ORP changes in terms of column operations. Hence It was important to note the pH and ORP in AMD to evaluate a risk assessment and a soil management using monitoring metals. When we operate AMD management with the mechanism of resolution and adsorption it can be achieved better economic solution.

Study on Construction of Soil Structure in Creation of Man-made Tidal Flat (인공 간석지 창출에 있어서 토양조성에 관한 연구)

  • Lee, Jeoung-Gyu;Suh, Hea-Dong
    • Journal of the Korea Organic Resources Recycling Association
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    • v.8 no.2
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    • pp.85-92
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    • 2000
  • The purpose of this study was to identify the controlling factors to construct tidal flat ecosystems having similar characteristics as natural ones. We transplanted the soil in a constructed tidal flat to a natural one and vice versa. Parameters monitored after these transplantations were silt content, organic matter, bacterial population and oxidation-reduction potential. Moreover, the relationship among silt content, organic matter and bacterial population was investigated by laboratory column experiment. The silt content, organic matter, bacterial population and vortical profile of oxidation-reduction potential in the soil transplanted from the constructed tidal flat to the natural one changed to similar values to those In the natural one. On the contrary, all the parameters for the soil transplanted from the natural tidal flat to the constructed one changed to similar values as those in the constructed one. The silt contents in these two transplanted soils were in proportion to the organic carbon contents and bacterial population. Similarly, the bacterial population in laboratory column experiment increased with the increase in silt and organic matter contents. It seemed to be important to select a place to enhance accumulative of silt and/or to maintain the silt content by hydrodynamic control of seawater in order to construct a tidal flat having similar characteristics as natural one.

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A Study on Autocontrolled SBR for Biological Nutrient Removal with External Carbon Sources (외부탄소원 주입시 영양염류의 생물학적 제거를 위한 자동제어 SBR 공정에 관한 연구)

  • Lee, Byung-hun;Kang, Seong-jae;Lim, Sung-il;Yoo, Pyung-jong
    • Journal of Korean Society on Water Environment
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    • v.18 no.4
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    • pp.371-377
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    • 2002
  • The purpose of this study is to develop effective operating process in order to achieve more suitable conditions of Anoxic-Oxic-Anoxic-Stripper(AOAS) SBR through real-time control. To improve the removal efficiency, glucose, methanol and synthetic food waste acid fermentant were added as an external carbon source, In the case of glucose and synthetic food waste acid fermentant, TN, TP were removed to average 86.9%, 73.0% respectively. Methanol was removed to average 64.6%, 55.4% respectively. The synthetic food waste acid fermentant proved to be the most efficient and allowed for the substitution of an external carbon source. The removal rate of $COD_{Cr}$, was approximately 90% at all cases. The results of the study that a correlation between ORP (Oxidation-Reduction Potential), pH and DO and nitrification or denitrification when an external carbon source is added and when it isn't was showed that ${\Delta}ORP$ is suitable parameter. ORP reacted properly to denitrification (${\Delta}ORP<-10$) and nitrification (${\Delta}ORP<0$). The use of real-time control saved anywhere between 61 and 67 minutes at the anoxic(1) stage and 26 to 52 minutes at the oxic(1) stage. When the time saved from the anoxic(1) and oxic(1) was added to the anoxic(2) stage for the removal efficiency of TN and TP increased from 0.7 to 13.9% and 12 to 35 % respectively.

Anodic Reactions at a Pb-Ag Anode in Sulfuric Acid Solutions Containing Manganese(II) (망간(II)을 함유한 황산용액에서 Pb-Ag 양극의 산화반응)

  • Lee, Man-Seung;Nicol, M.J.
    • Resources Recycling
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    • v.26 no.4
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    • pp.34-41
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    • 2017
  • The effect of Mn(II) concentration on the anodic reactions occurring on a Pb-Ag electrode in sulfuric acid solutions has been studied by potentiostatic oxidation in the potential range of 1.8 to 2.0 V. High oxidation potentials and low initial concentrations of Mn(II) resulted in higher concentrations of soluble Mn(III) ions which were obtained from spectrophotometric analysis of the solution after oxidation. $MnO_2$ was deposited on the electrode by electrochemical oxidation of Mn(II) at 1.8 and 1.9 V, while it was formed by disproportionation of Mn(III) at 2.0 V. No $PbO_2$ was formed in the presence of Mn(II) during potentiostatic oxidation treatment for two hours at 1.8 V. Chemical reduction of $PbO_2$ with Mn(II) led to a decrease in the amount of $PbO_2$ as Mn(II) concentration increased at 1.9 and 2.0 V.

Characterization of the Interaction of Sulfiredoxin (Srx1) with a Vacoular Protein $\alpha$-Mannosidase (Ams1) in Saccharomyces cerevisiae (설피리독신과 알파-만노시다제 간의 단백질 결합 특성에 관한 고찰)

  • Barando, Karen P.;Kim, Il-Han
    • The Journal of Natural Sciences
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    • v.17 no.1
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    • pp.13-29
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    • 2006
  • Most redox-active proteins have thiol-bearing cysteine residues that are sensitive to oxidation. Cysteine thiols oxidized to sulfenic acid are generally unstable, either forming a disulfide with a nearby thiol or being further oxidized to a stable sulfinic acid, which have been viewed as an irreversible protein modification. However, recent studies showed that cysteine residues of certain thiol peroxidases (Prxs) undergo reversible oxidation to sulfinic acid and the reduction reaction is catalyzed by sulfiredoxin (Srx1). Specific Cys residues of various other proteins are also oxidized to sulfinic acid ($Cys-So_2H$). Srxl is considered one of the oxidant proteins with a role in signaling through catalytic reduction of oxidative modification like in the reduction of glutathionylation, a post-translational, oxidative modification that occurs on numerous proteins. In this study, the role of sulfiredoxin in cellular processes, was investigated by studying its interaction with other proteins. Through the yeast two-hybrid system (Y2HS) technique, we have found that Ams1 is a potential and novel interacting protein partner of Srxl. $\alpha$-mannosidase (Ams1) is a resident vacuolar hydrolase which aids in recycling macromolecular components of the cell through hydrolysis of terminal, non-reducing $\alpha$-D-mannose residues. It forms an oligomer in the cytoplasm and under nutrient rich condition and is delivered to the vacuole by the Cytoplasm to Vacuole (Cvt) pathway. Aside from the role of Srxl as a catalyst in the reduction of cysteine sulfenic acid groups, it may play a completely new function in the cellular process as indicated by its interaction with Ams1 of the yeast Saccharomyces cerevisiae.

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Assessment and Analysis of Coal Seam Gas Water Management Study for Water Resource Production 2. Prediction of Treatment Technology and Design of Co-treatment System (물 자원 생산을 위한 Coal Seam Gas Water Management Study의 평가 및 분석 2. 처리기술 예측 및 병합 시스템 설계)

  • Shin, Choon-Hwan
    • Journal of Environmental Science International
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    • v.24 no.12
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    • pp.1629-1637
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    • 2015
  • To develop various usable water from coal seam gas (CSG) water that needs to be pumped out from coal seams for methane gas production, a feasibility study was carried out, evaluating and analysing a recent report (Coal Seam Gas Water Management Policy 2012) from Queensland State Government in Australia to suggest potential CSG water treatment options for fit-for-purpose usable water production. As CSG water contains intrinsically high salinity-driven total dissolved solid (TDS), bicarbonate, aliphatic carbon, $Ca^{+2}$, $Mg^{+2}$ and so on, it was found that appropriate treatment technologies are required to reduce the hardness below 60 mg/L as $CaCO_3$ by setting the reduction rates of $Ca^{+2}$, $Mg^{+2}$ and Na+ concentrations, as well as TDS reduction. Also, Along with fiber filtration and membrane separation, an oxidation degradation process was found to be required. Along with salinity reduction, as CSG water contains organic compounds (TOC: 248 mg/L, $C_6-C_9$: <20 mg/L and $C_{10}-C_{36}$: <60 mg/L), compounds with relatively high molecular weights ($C_{10}-C_{36}$) need to be treated first. Therefore, this study suggests a combined system design with filtration (Reverse osmosis) and oxidation reduction (electrolysis) technologies, offering proper operating conditions to produce fit-for-purpose usable water from CSG water.

A Study on the Recovery of Zn from Electric Arc Furnace Dust by Carbon Reduction

  • Joo, Sung-Min;Kim, Hyung-Seok;Ahn, Ji-Whan;Kim, Hwan;Lee, Kyung-Hoon;Sung, Ghee-Woong;Kim, Jang-Su;Lee, Park-Seok
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.398-403
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    • 2001
  • There is a potential usability of electric arc furnace(EAF) dust produced during the iron manufacturing process as a recycled resource, because valuable materials such as Zn, Pb and Fe are contained in it. In this study, metallic Zn was recycled from the fine electric arc furnace dust by a solid state reduction method using carbon at relatively low temperature. It was possible to recover metallic zinc by using of high vapour pressure of zinc with this reduction method. The feasibility of recycled zinc for cold bonded pellet(CBP) was investigated. The main composition of EAF dust were franklinite(ZnFe$_2$O$_4$), magnetite(Fe$_3$O$_4$) and zincite(ZnO), and Pb and Cl were completely removed by a heat treatment in oxidation environment. The reduction ratio increased as the solid carbon content increased, and it increased with decreasing of dust particle size and increasing of compaction pressure due to a increase of contact area.

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Study on the in vitro and in vivo anti-obesity effects of a combination of Syzygium aromaticum L. and Sorbus commixta Hedl. (정향과 마가목 복합물의 in vitro와 in vivo 항비만 효과 연구)

  • Ji Heon Yu;Hui Yeon An;Seong-Soo Roh;Mi-Rae Shin
    • Journal of Nutrition and Health
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    • v.57 no.2
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    • pp.196-210
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    • 2024
  • Purpose: This study investigated the anti-obesity effects of a combination of Syzygium aromaticum L. and Sorbus commixta Hedl. (SS) in vitro and in vivo. Methods: The extracts of Syzygium aromaticum extract (SA) and Sorbus commixta extract (SC) were prepared individually using distilled water. They were mixed in a 1:2 ratio for use in the experiment. To assess the anti-obesity potential of SS in vitro, we examined cell proliferation, cellular triglyceride (TG), and total cholesterol (TC) levels, as well as lipogenesis and β-oxidation in 3T3-L1 cells. To confirm its anti-obesity potential in vivo, C57BL/6J mice were fed a 60% high-fat diet (HFD) to induce obesity. SA alone, SC alone, and their combination compound, SS (at a dosage of 200 mg/kg) were orally administered for 6 weeks. Thereafter, to conduct a comparative evaluation, serum analysis, western blotting of liver tissues, and histopathological analysis were performed. Results: Both SS200 and SS400 significantly inhibited the cellular TG and TC contents in the 3T3-L1 cells. Furthermore, treatment of the cells with SS (at a dose 200 and 400 ㎍/mL) also led to a noticeable regulation of key lipogenic and β-oxidation factors. Treatment of obese mice with SS resulted in a greater reduction in serum leptin and TG levels compared to treatment with the individual compounds (SA and SC). Furthermore, activation of AMP-activated protein kinase α by SS treatment resulted in the suppression of sterol regulatory element-binding proteins (SREBP)-1, leading to the inhibition of acetyl-CoA carboxylase (ACC) expression. Conclusion: Our results suggest that SS may have the potential to prevent obesity through a reduction in the TG and TC levels and regulation of lipogenesis and β-oxidation.

A Portable Potentiostat with Bluetooth Communication for Square wave Voltammetry Measurement (네모파 전압전류법 측정을 위한 블루투스 기반 휴대형 포텐쇼스탯)

  • Shim, Wonsik;Han, Ji-Hoon;Kim, Suyun;Kwon, Hyun Jeong;Pak, Jungho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.4
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    • pp.622-627
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    • 2016
  • This paper describes the development of a portable potentiostat which can perform square wave voltammetry on electrochemical sensors and wireless transmission of the measured data to a smartphone using Bluetooth. The potentiostat consists of a square wave potential pulse generation circuit for applying the potential pulse to the electrochemical sensor, a reduction/oxidation (or redox) current measurement circuit, and Bluetooth for wireless data transmission to an Android-based smartphone. The measured data are then processed to show the output graph on the smart phone screen in real time. This data transformation into a graph is carried out by developing and installing a simple transformation application software in the Android-based smartphone. This application software also enables the user to set and change the measurement parameters such as the applied voltage range and measured current range at user's convenience. The square voltammetry output data measured with the developed portable potentiostat were almost same as the data of the commercial potentiostat. The measured oxidation peak current with the commercial potentiostat was $11.35{\mu}A$ at 0.26 V and the measured oxidation peak current with the developed system was $12.38{\mu}A$ at 0.25 V. This proves that performance of the developed portable measurement system is comparable to the commercial one.