• Title/Summary/Keyword: Oxidation/reduction potential(ORP)

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Surface Sterilization Effect of Electrolyzed Acid-water on Vegetable (전해 산화수의 채소류 표면 살균 효과)

  • Jung, Sung-Won;Park, Kee-Jai;Park, Kyung-Jo;Park, Byoung-In;Kim, Young-Ho
    • Korean Journal of Food Science and Technology
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    • v.28 no.6
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    • pp.1045-1051
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    • 1996
  • The influence of electrolyzed acid-water (oxidation-reduction potential (ORP): above 1,150 mV, pH : 2.5) on the survival of some microorganisms was investigated. It was observed that the ORP of electrolyzed acid-water was kept at the level of above 1,000 mV for 15 days at room temperature. Escherichia coli. Salmonella typhi, Staphylococcus aureus and Saccharomyces cerevisiae were not detected after 10 to 40 min in electrolyzed acid-water. However, Bacillus cereus showed higher tolerance to electrolyzed acid-water than other test microorganisms. After 60 min of inoculation, only 0.4% of initial population remained. The investigation of surface sterilization effect on some vegetables was carried out too. Total count of cabbage, Chinese cabbage and kale were reduced to below 3% of initial count, and no coliform was detected after 20 to 60 min of immersion in 5 volumes of electrolyzed acid-water. In the lettuce, total and coliform counts were reduced to 90% and 2% of initial population. This study shows that the electrolyzed acid-water has a potential for the sterilization of food products such as vegetables and fruits which cannot be thermally sterilized.

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A Study on the Atmospheric Dry Deposition Flux and Soil Contamination in a Completed Landfill - A case study on Nanji landfill - (사후관리단계에 있는 매립지의 건식침적량 및 토양오염에 관한 연구 -난지도 매립지 사례를 중심으로-)

  • Yi, Seung Muk;Cho, Kyung Suk;Lee, Eun Young;Kim, Yoon Jung;Park, Jae Woo;Park, Seok Soon
    • Journal of Environmental Impact Assessment
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    • v.8 no.2
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    • pp.31-44
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    • 1999
  • Atmospheric dry deposition flux and ambient particle mass size distribution were measured to evaluate the impact of atmospheric deposition around the Nanjido landfill sites. Wind direction affects greatly on the variation of mass flux and mass size distribution and made two times higher when the wind was blown from the road side. The effect of Nanjido landfill on the mass size distribution was significant comparing to simultaneously measured mass size distribution at the other sampling site. The results showed that the particle diameter bigger than $10{\mu}m$ explained the majority of atmospheric dry deposition flux. A survey was also carried out to investigate the contamination of soils in a completed Nanjido landfill. The chemical properties of the soil analyzed in the present study include pH, oxidation-reduction potential (ORP), anion and cation concentration, total organic carbon(TOC), and some-metal elements concentrations were analyzed. Microbial activity in the soils was also evaluated by measuring dehydrogenase activities. TOC in the soil contaminated with leachate was $467.0{\mu}g/g-dry$ soil, and the TOC in the soil, where Nanjido landfill gases were emitted from, was $675{\mu}g/g-dry$ soil. The highest microbial activity of $968.0{\sim}2147{\mu}g-TPF/g-dry$ soil day was found in the soil spouting Nanjido landfill gases. Compared with those in the uncontaminated soil, the concentrations of Cr, Cu and Ph in the contaminated soil were higher.

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Remediation of Muddy Tidal Flat using Porous Pile (다공질 파일을 이용한 점토질 갯벌의 저질환경개선)

  • Kim, Kyunghoi;Lee, In-Cheol;Kang, Yoon-Koo;Hibino, Tadashi
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.1
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    • pp.9-13
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    • 2015
  • Field experiment were carried out to investigate the formation of ground water flow and remediation of muddy tidal flat by installation of porous pile at the tidal flat of brackish river located in Hiroshima City, Japan. After the installation of porous pile, the concentrations of Dissolved Oxygen (DO) in the interstitial water in the porous pile increased with maximum concentration of 4 mg/L due to a formation of groundwater flow. It was observed that a increase in Oxidation Reduction Potential (ORP) and a decrease in Ignition Loss (IL) in the porous pile site and these must be caused by the increase of dissolved oxygen in the interstitial water. From these results obtained above, it is concluded that the porous pile is an effective technology for remediation of muddy tidal flats.

Decolorization System of Effluent of Activated Sludge Process Using Ozone (오존에 의한 활성오니처리 방류수의 탈색처리 연구)

  • 최희철;곽정훈;최동윤;권두중;김형호;이덕수;강희설;최영수;천상석
    • Journal of Animal Environmental Science
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    • v.8 no.3
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    • pp.153-158
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    • 2002
  • Decolorization system using ozone was developed to reduce the pollutants and dark brown color remained in effluent of activated sludge process for pig wastewater. The results are as follows. 1. Wastewater temperature was increased during the ozone treatment from 31$^{\circ}C$ to 41.9$^{\circ}C$. 2. Oxidation reduction potential(ORP) at the beginning time was 148㎷, but it was increased to 330㎷ according to the ozone treatment. 3. 11mg/l of BO $D_{5}$ in effluent of activated sludge process was decreased to 1mg/l by ozone treatment, CO $D_{MN}$ also decreased from 83mg/l to 1.0mg/l. 4. 442 unit(dark brown color) of color in effluent of activated sludge process was changed to 6 units(colorless), and color removal efficiency was 98.6%.

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Nitrogen and Phosphorus Removal in Domestic Wastewater using SBR Process with Flow Changing Continuous Feed and Cyclic Draw (교대연속유입식 SBR 공정을 이용한 하수중의 질소 및 인 제거)

  • Seo, In-seok;Kim, Hong-suck;Kim, Youn-kwon;Kim, Ji-yeon
    • Journal of Korean Society on Water Environment
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    • v.22 no.2
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    • pp.203-208
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    • 2006
  • A continuous feed and cyclic draw SBR process was developed to overcome flow rate fluctuation and to maximize organic matters utilization efficiency for nitrogen and phosphorus removal. The developed SBR process was operated with two parallel reactors. Influent was supplied to one reactor which was not obligately aerated. At the same time, the other reactor was just aerated without supplying influent. In addition this mode was changed periodically. Cycle time was 6hr and aeration time ratio($t_{aer}/t_{total}$) was 0.33, respectively. $COD_{cr}$ and SS removal efficiencies of 95% or higher were achieved. Nitrogen removal was so greatly influenced by influent $COD_{cr}/T-N$ ratio. At influent $COD_{cr}/T-N$ ratio of 5.7, removal efficiencies of ammonia-N, T-N and T-P were 96%, 78% and 55%, respectively. Influent $COD_{cr}/T-N$ of 4 or higher ratio was necessary to achieve 60% or higher nitrogen removal. Organic matters of influent was efficiently utilized in denitrification reaction and consumed COD has a good correlation with removed T-N(about 6.5 mgCOD/mgTN). Continuous feed and cyclic draw SBR process could be one of alternative processes for the removal of nutrients in rural area where $COD_{cr}/T-N$ ratio was low and fluctuation of flow rate was severe.

Effect of Anti-Microbial Materials on Storages of Ssamjang (항균물질 첨가에 의한 쌈장의 저장중 품질특성)

  • Kang, Bo-Ra;Im, Go-Eun;Kim, Dong-Han
    • Journal of Applied Biological Chemistry
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    • v.56 no.1
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    • pp.11-17
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    • 2013
  • The effect of additives on the quality of ssamjang was investigated during storage. The L-, a- and b-values of ssamjang decreased gradually during storage, and the total color difference (${\Delta}E$) increased in the control group. The gas production of ssamjang was reduced in K-sorbate, alcohol and mustard added groups. The number of yeast increased rapidly up to 6 weeks of storage, then decreased in the mustard, alcohol, and K-sorbate added groups. The oxidation-reduction potential and water activity decreased until 6 weeks and 12 weeks, respectively, and then increased gradually. Titratable acidity increased with concomitant decrease in pH, however, it increased slightly in the K-sorbate and ethanol added groups. Reducing sugar content increased until 9 weeks of storage, except the turmeric added group. Alcohol content increased until 15 weeks in the Japanese apricot juice, and turmeric added group. The sensory test result for the taste, flavor and overall acceptability showed that mustard added ssamjang was more acceptable than other groups.

Estimation of verticle fluxes of nitrogen compounds in tidal flats of the Keum river estuary (금강하구 갯벌내 질소화합물질의 연직적인 플럭스 평가)

  • Kim Do Hee;Yang Jae Sam
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.3 no.2
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    • pp.3-10
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    • 2000
  • The main purpose of this study were to estimate the benthic fluxes of dissolved inorganic nitrogen (DIN) from the sediment and denitrification rates in tidal flats of the Keum river estuary. Sediment specimens were collected by a core sampler from three stations along the Keum river estuary in April, August and December, 1999. The sediments were composed of 1.18 %, 29.34 % and 69.49 % of gravel and sand, sand and silt, respectively. The mean ignition loss of the sediment was found 6.7 % and its Oxidation Reduction Potential (ORP) was measured -12 mV. The total hydrogen sulfides was determined about 0.26 mg/gㆍdry. The estimated outflux of ammonium was found 11.2 m mole N/m²ㆍday from the sediment, whereas -1.09 m mole N/m²ㆍday of influx was obtained for nitrate and nitrite through the incubation experiment of sediment cores. Total DIN flux was 10.2 m mole N/m²ㆍday outflux from the sediment. From the incubation experiments executed with the flux studies, mean denitrification rate was found 30.6 m mole N₂/m²ㆍday measured by the direct assay of N₂ production technique. On the basis that DIN flux and denitrification rate in sediment of tidal flat of the Keum river estuary are may be effects to control the algal biomass in the coastal environment, it seems inevitable to pay more attention to investigate the flux of DIN and denitrification rate in tidal flat of the Keum river estuary.

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Microbiological Cleaning Effect of Electrolyzed Acid Water by Containing Polysorbates (Polysorbates를 첨가한 전해산화수의 미생물학적 세정효과)

  • Jeong, Jin-Woong;Park, Kee-Jai;Jung, Sung-Won
    • Korean Journal of Food Science and Technology
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    • v.31 no.4
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    • pp.1029-1034
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    • 1999
  • To enhance the cleaning and sterilization effect of cooled electrolyzed acid water on lettuce, several kinds of polysorbates were used at various concentrations in immersion washing process. In case of the treatment containing polysorbate 20, coliform count of lettuce was reduced to about 1/40 level of that in non-treated lettuce. The treatment containing polysorbate 60 did not show a significant sterilization effect. Otherwise, the total and coliform counts of lettuce during immersion in electrolyzed acid water containing 1 ppm of polysorbate 80 was reduced to about 1/300 and 1/1,700 level of those in non-treated one. And, the changes of ORP(oxidation-reduction potential), pH and color value of lettuce in electrolyzed acid water containing 1 ppm of polysorbate 80 were not quite different during 60 min. immersion, but HCIO content decreased from 10.28 ppm to 8.51 ppm after 20 min. immersion. Also, total and coliform count of lettuce immersed in electrolyzed acid water containing 1 ppm of polysorbate 80 was lower to about 1/1,800 after 20 min. and 1/5,550 after 30 min, compared with non-treated lettuce.

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A New Cleaning Concept for Display Manufacturing Process with Electrolyzed Anode Water (전해 양극수를 이용한 새로운 디스플레이 세정)

  • Ryoo Kunkul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.6 no.1
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    • pp.78-82
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    • 2005
  • Display manufacturing process has adopted RCA cleaning, applying to larger area and coping with environmental issue for last ten years. However, the approaching concept of ozonized, hydrogenised, or electrolyzed water cleaning technologies is within RCA clean paradigm. In this work, only electrolyzed anode water was applied to clean particles and organics as well as metals based on Pourbaix concept, and as a test vehicle, MgO particles were introduced to prove the new concept. The electrolyzed anode water is very oxidative with high oxidation reduction potential (ORP) and low in pH of more than 900 mV and 3.1, respectively. MgO particles were immersed in the anode water and its weight losses due to dissolution were measured with time. Weight losses were in the ranges of 100 to 500 micrograms in 250 ml anode water depending on their ORP and pH. Therefore it was concluded that the cleaning radicals in the anode water was at least in the range of 1 to $5{\times}10^{20}$ ea per 250 ml anode water equivalent to $1{\times}10^{18} ea/cm^2$. Hence it can be assumed that the anode water applied to display cleaning from now on $1{\times}10^{10}$ to $1{\times}10^{15} ea/cm^2$ ranges of contaminants are being treated. In addition, it was observed that anode water did not develop micro-roughness on hydrophobic surface while it did on the native silicon oxide.

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The Effects of Balneotherapy in Alkaline Reduced Spring Water on Skin Injury Induced by UV Irradiation in Hairless Mice (자외선으로 손상된 무모생쥐의 피부에 알칼리환원온천수의 침수치료효과)

  • Yoon, Yang-Suk;Kim, Dong-Heui;Jin, Dan;Park, Mi-Soon;Chang, Byung-Soo;Lee, Jee-Yeon;Lee, Kyu-Jae
    • Applied Microscopy
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    • v.41 no.1
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    • pp.21-29
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    • 2011
  • Balneotherapy has been widely used for the treatment of skin diseases in the world. The purpose of this study was to determine the bath effect of the alkaline reduced spring water with the properties of high pH and low oxidation reduction potential (ORP) on the skin injury induced by ultra violet (UV) irradiation. For this purpose, hairless mice were irradiated with UV-B to cause skin injury, and individually taken a bath in spring water (experimental group) and tap water (control group) once a day for 40 min during 21 days. We observed histological changes of the back skin through macro- and microscopic methods compared to the control group. We found that skin injury of the experimental group was more quickly recovered than that of the control group. Under the light microscope, the experimental group showed that epidermal thickening (p<0.01) and the mast cell activation (p<0.001) were lower compared with the control group, in addition infiltration of inflammatory cells and degranulation of mast cells were less observed. These results suggest that regular bath in the spring water with the properties of high pH and low ORP has a positive effect on the skin injury induced by UV irradiation.