• Title/Summary/Keyword: 오염물질과 반응

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Quality Evaluations of Seasoning Chicken Containing Pine Needles During Cold Storage (솔잎 닭고기 양념육의 냉장동안 품질평가)

  • Kim, Chang-R.;Kim, Kwang-H.
    • Food Science of Animal Resources
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    • v.27 no.1
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    • pp.47-52
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    • 2007
  • Quality evaluations of seasoning chicken wing treated with pine needles during storage of 6 days at $4^{\circ}C$ were assessed. Seasoning chicken containing 0.5-1.3% (w/w) pine needle during storage at $4^{\circ}C$ was allowed to the growth of Staphylococcus aureus. pH values of seasoning chicken containing pine needles after 6 days of storage were not significantly different (p>0.05) than those of the controls. The rate of drip loss on seasoning chicken containing pine needles after 24 hr of storage was significantly different (p<0.05) than that of the controls. Sensory scores of seasoning chicken containing 0.8-1.3% pine needles for odor and flavor were in the "liked more" to typical category during storage of 6 days at $4^{\circ}C$. For odor and flavor scores, seasoning chicken containing 1.0-1.3% pine needles compared to the controls and other treatments increased during storage days due to fresh odor of pine needles. Seasoning chicken containing 0.5-1.3% pine needles after 6 days of storage were no significantly different levels (p>0.05) of Hunter color $L^*$ values compared to controls. Hunter color $a^*$ and $b^*$ values of seasoning chicken containing 0.5-1.3% pine needles after 6 days of storage were significantly different (p<0.05) than those of the controls.

Study on the Oxidation and Dissolution Characteristics of Biogenic Mackinawite (미생물 기원 맥키나와이트의 산화 및 용해 특성 연구)

  • Lee, Seung-Yeop;Baik, Min-Hoon;Jeong, Jong-Tae
    • Journal of the Mineralogical Society of Korea
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    • v.25 no.3
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    • pp.155-162
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    • 2012
  • We observed characteristic oxidation and dissolution phenomena induced by dissolved oxygen for mackinawite that is produced via sulfate-reducing bacteria (SRB) living in anaerobic environments such as soils and groundwater. We tried to recognize the role of the sulfide minerals that usually coexist with some stabilized radionuclides (e.g., reduced uranium), which can be reoxidized and redissolved by an oxygen-rich groundwater invaded into a contaminated area. The mackinawite produced by 'Desulfovibrio desulfuricans', a sulfate-reducing bacterium, was conducted to be dissolved for 2 weeks by some oxidants such as 'hydrogen peroxide' and 'sodium nitrite'. Although mineralogical oxidation and dissolution characteristics were different from each other according to the oxidants, the initially oxidized solution was early stabilized through the oxygen consumption by ${\mu}m$-sized sulfide particles and the resultant increase of sulfate in solution. From these results, we can anticipate that the large amount of sulfide minerals generated by SRB can not only repress the anoxic environment to be disturbed by the consumption of oxygen in groundwater, but also contribute to stabilize the reduced/precipitated radionuclides as a buffer material for a long time.

Comparison of Anoxic/Oxic Membrane Bioreactor - Reverse Osmosis and Activated Sludge Process-Microfiltration-Reverse Osmosis Process for Advanced Treatment of Wastewater (폐수의 고도처리를 위한 무산소/호기형 분리막생물반응조 - 역삼투 공정과 활성슬러지공정 - 정밀여과 - 역삼투 공정의 비교)

  • Roh, Sung-Hee;Kim, Sun-Il;Quan, Hong-hua;Song, Yon-Ho
    • Applied Chemistry for Engineering
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    • v.17 no.5
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    • pp.521-526
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    • 2006
  • A membrane bioreactor (MBR) is an effective tool for wastewater treatment with recycling. MBR process has several advantages over conventional activated sludge process (ASP); reliability, compactness, and quality of treated water. The resulting high-quality and disinfected effluents suggest that MBR process can be suitable for the reused and recycling of wastewater. An anoxic/oxic (A/O) type MBR was applied to simultaneous removal of organics and nutrients in sewage. At first, the efficiency of submerged MBR process was investigated using a hollow fiber microfiltration membrane with a constant flux of $10.2L/m^2{\cdot}h$ at each solids retention time (SRT). Results showed that protein/carbohydrate (P/C) ratio increased and total extracellular polymeric substances (EPS) remained constant with SRT increased. Secondly, A/O type MBR with a reverse osmosis (RO) membrane was employed to treat the municipal wastewater. The performance of A/O type MBR-RO process is better for the treatment of organics and nutrients than ASP-MF-RO process in terms of consistent effluents quality.

Characteristics of Strong Alkaline Electrolyzed Water Produced in All-in-one Electrolytic Cell (일체형 전해조에서 생산된 강알카리성 전해수의 특성)

  • Lee, Ho Il;Rhee, Young Woo;Kang, Kyung Seok
    • Clean Technology
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    • v.18 no.4
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    • pp.446-450
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    • 2012
  • Strong alkaline electrolyzed water which is produced in cathode by electrolyzing the solution where electrolytes (NaCl, $K_2CO_3$ etc.) are added in diaphragm electrolytic cell, is eco-friendly and has cleaning effects. So, it is viewed as a substitution of chemical cleaner. In addition, strong alkaline electrolyzed water is being used by some Japanese automobile and precision parts manufacturing industries. When strong alkaline electrolyzed water is produced by using diaphragm electrolytic cell, it is necessarily produced at the anode side. Since strong acidic electrolyzed water produced is discarded when its utilization cannot be found, production efficiency of electrolyzed water is consequently decreased. Also, there is a weakness electrolytic efficiency is decreasing due to the pollution of diaphragm. In order to overcome this, non-diaphragm all-in-one electrolytic cell integrated with electrode reaction chamber and dilution chamber was applied. Strong alkaline electrolyzed water was produced for different composition of electrolytes, and their properties and characteristics were identified. In comparing the properties between strong alkaline electrolyzed water produced in diaphragm electrolytic cell and that produced in all-in-one electrolytic cell, the differences in ORP and chlorine concentration were found. In emulsification test to confirm surface-active capability, similar results were obtained and strong alkaline electrolyzed water produced in non-diaphragm all-in-one electrolytic cell was identified to be useable as a cleaner like strong alkaline electrolyzed water produced in diaphragm electrolytic cell. Strong alkaline electrolyzed water produced in non-diaphragm all-in-one electrolytic cell is thought to have sterilizing power because it has active chlorine which is different from strong alkaline electrolyzed water produced in diaphragm electrolytic cell.

Significance of Dissimilatory Fe(III) Reduction in Organic Matter Oxidation and Bioremediation of Environmental Contaminants in Anoxic Marine Environments (혐기성 해양환경에서 철 환원세균에 의한 유기물 분해 및 생물정화)

  • Hyun Junc-Ho
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.10 no.3
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    • pp.145-153
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    • 2005
  • I reviewed an ecological and environmental significance of microbial carbon respiration coupled to dis-similatory reduction of fe(III) to Fe(II) which is one of the major processes controlling mineralization of organic matter and behavior of metals and nutrients in various anaerobic environments. Relative significance of Fe(III) reduction in the mineralization of organic matter in diverse marine environments appeared to be extremely variable, ranging from negligible up to $100\%$. Cenerally, Fe(III) reduction dominated anaerobic car-bon mineralization when concentrations of reactive Fe(III) were higher, indicating that availability of reactive Fe(III) was a major factor determining the relative significance of Fe(III) reduction in anaerobic carbon mineralization. In anaerobic coastal sediments where $O_2$ supply is limited, tidal flushing, bioturbation and vegetation were most likely responsible for regulating the availability of Fe(III) for Fe(III) reducing bacteria (FeRB). Capabilities of FeRB in mineralization of organic matter and conversion of metals implied that FeRB may function as a useful eco-technological tool for the bioremediation of anoxic coastal environments contaminated by toxic organic and metal pollutants.

The Effects of Fertilization on Growth Performances and Physiological Characteristics of Liriodendron tulipifera in a Container Nursery System (시비 처리가 백합나무 용기묘의 생장 및 생리적 특성에 미치는 영향)

  • Cho, Min Seok;Lee, Soo Won;Park, Byung Bae;Park, Gwan Su
    • Journal of Korean Society of Forest Science
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    • v.100 no.2
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    • pp.305-313
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    • 2011
  • Fertilization is essential to seedling production in nursery culture, but excessive fertilization can contaminate surface and ground water around the nursery. The objective of this study was to find optimal fertilization practice of container seedling production for reducing soil and water contamination around the nursery without compromising seedling quality. This study was conducted to investigate growth performance, photosynthesis, chlorophyll fluorescence, and chlorophyll contents of Liriodendron tulipifera growing under three different fertilization treatments (Constant rate, Three-stage rate, and Exponential rate fertilization). Root collar diameter, height, and biomass of L. tulipifera were the highest at Constant treatment. Like growth performance, seedling quality index (SQI) were higher at Constant than at other treatments, but not significantly different among treatments. L. tulipifera showed good photosynthetic capacity at all treatments. Photochemical efficiency and chlorophyll contents were significantly lower at Exponential than at other treatments. Therefore, Exponential fertilization which is 50% fertilizer of other treatments would maximize seedling growth and minimize nutrient loss.

Application of Ferrate (VI) for Selective Removal of Cyanide from Plated Wastewater (도금폐수 중 시안(CN)의 선택적 제거를 위한 Ferrate (VI) 적용)

  • Yang, Seung-Hyun;Kim, Younghee
    • Clean Technology
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    • v.27 no.2
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    • pp.168-173
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    • 2021
  • The treatment of plated wastewater is subject to various and complex processes depending on the pH, heavy metal, and cyanide content of the wastewater. Alkali chlorine treatment using NaOCl is commonly used for cyanide treatment. However, if ammonia and cyanide are present simultaneously, NaOCl is consumed excessively to treat ammonia. To solve this problem, this study investigated 1) the consumption of NaOCl according to ammonia concentration in the alkaline chlorine method and 2) whether ferrate (VI) could selectively treat the cyanide. Experiments using simulated wastewater showed that the higher the ammonia concentration, the lower the cyanide removal rate, and the linear increase in NaOCl consumption according to the ammonia concentration. Removal of cyanide using ferrate (VI) confirmed the removal of cyanide regardless of ammonia concentration. Moreover, the removal rate of ammonia was low, so it was confirmed that the ferrate (VI) selectively eliminated the cyanide. The cyanide removal efficiency of ferrate (VI) was higher with lower pH and showed more than 99% regardless of the ferrate (VI) injection amount. The actual application to plated wastewater showed a high removal ratio of over 99% when the input mole ratio of ferrate (VI) and cyanide was 1:1, consistent with the molarity of the stoichiometry reaction method, which selectively removes cyanide from actual wastewater containing ammonia and other pollutants like the result of simulated wastewater.

Electrochemical Evaluation of Cadmium and Lead by Thiolated Carbon Nanotube Electrodes (티올화된 탄소나노튜브 전극을 이용한 카드뮴과 납의 전기화학적 분석)

  • Yang, Jongwon;Kim, Lae-Hyun;Kwon, Yongchai
    • Applied Chemistry for Engineering
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    • v.24 no.5
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    • pp.551-557
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    • 2013
  • In the present study, pristine carbon nanotube (p-CNT) and thiolated carbon naotube (t-CNT) electrodes were investigated to improve their detectabilities for cadmium (Cd) and lead (Pb). In addition, we evaluate which reaction mechanism is used when the electrolyte contains both Cd and Pb metals. Square wave stripping was employed for analyzing the sensitivity for the metals. A frequency of 30 Hz, a deposition potential of -1.2 V vs. Ag/AgCl and a deposition time of 300 s were used as optimal SWSV parameters. t-CNT electrodes show the better sensitivity for both Cd and Pb metals than that of p-CNT electrodes. In case of Cd, sensitivities of p-CNT and t-CNT electrodes were $3.1{\mu}A/{\mu}M$ and $4.6{\mu}A/{\mu}M$, respectively, while the sensitivities for Pb were $6.5{\mu}A/{\mu}M$ (p-CNT) and $9.9{\mu}A/{\mu}M$ (t-CNT), respectively. The better sensitivity of p-CNT electrodes is due to the enhancement in the reaction rate of metal ions that are facilitated by thiol groups attached on the surface of CNT. When sensitivity was measured for the detection of Cd and Pb metals present simultaneously in the electrolyte, Pb indicates better sensitivity than Cd irrespective of electrode types. It is ascribed to the low standard electrode potential of Pb, which then promotes the possibility of oxidation reaction of the Pb metal ions. In turn, the Pb metal ions are deposited on the electrode surface faster than that of Cd metal ions and cover the electrode surface during deposition step, and thus Pb metals that cover the large portion of the surface are more easily stripped than that of Cd metals during stripping step.

A Study on the Oxy-Combustion of the Coal in Drop Tube Furnace (Drop Tube Furnace에서 석탄의 순산소 연소 특성)

  • Roh, Seon Ah;Yun, Jin Han;Lee, Jung Kyu;Keel, Sang In;Min, Tai Jin;Kim, Sang-Bok;Park, In-Yong;Han, Bangwoo;Kim, Jin-Tae
    • Clean Technology
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    • v.27 no.4
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    • pp.367-371
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    • 2021
  • The oxy-combustion system is one of the carbon recovery and storage technologies (CCS: Carbon capture & storage) that performs coal combustion using pure oxygen and recirculated flue gas. This is a technology that facilitates storage of carbon dioxide by generating an exhaust gas consisting of only carbon dioxide without a process of separating carbon dioxide and nitrogen when coal is burned using pure oxygen and recirculated flue gas mixture instead of a conventional air combustion system that produces carbon dioxide and nitrogen mixed exhaust gas. In this study, the characteristics of generated NO and SO2 as atmospheric pollutants during oxy-combustion were examined using O2/CO2 mixed simulation gas. The reaction temperature was varied from 900 ℃ to 1200 ℃ and oxygen partial pressure was varied from 30% to 50%. The results showed that NO and SO2 concentrations in flue gas increased as the oxygen concentration and the reaction temperature in the furnace increased. The partial pressure of CO2 in flue gas also increased as the oxygen concentration and the reaction temperature in the furnace increased. As a results of comparing NO production of 30% O2/CO2 oxy-combustion with air combustion, NO in flue gas increased with reaction temperature in both experiments and NO of oxy-combustion was 40 ~ 80 ppm lower than that of air combustion.

Selection of Filamentous Cyanobacteria and Optimization of Culture Condition for Recycling Waste Nutrient Solution (폐양액 활용을 위한 Filamentous Cyanobacteria의 선발 및 최적배양)

  • Yang, Jin-Chul;Chung, Hee-Kyung;Lee, Hyoung-Seok;Choi, Seung-Ju;Yun, Sang-Soon;Ahn, Ki-Sup;Sa, Tong-Min
    • Korean Journal of Soil Science and Fertilizer
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    • v.37 no.3
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    • pp.177-183
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    • 2004
  • The discharge of waste nutrient solution from greenhouse to natural ecosystem leads to the accumulation of excess nutrients that results in contamination or eutrophication. There is a need to recycle the waste nutrient solution in order to prevent the environmental hazards. The amount and kind of nutrients in waste nutrient solution might be enough to grow photosynthetic microorganisms. Hence in the present study, we examined the growth and mass cultivation of cyanobacteria in the waste nutrient solution with an objective of removing N and P and concomitantly, its mass cultivation. Four photosynthetic filamentous cyanobacteria (Anabaena HA101, HA701 and Nostoc HN601, HN701) isolated from composts and soils of the Chungnam province were used as culture strains. Among the isolates, Nostoc HN601 performed faster growth rate and higher N and P uptake in the BG-II ($NO_3{^-}$) medium when compared to those of other cyanobacterial strains. Finally, the selected isolate was tested under optimum conditions (airflow at the rate of $1L\;min^{-1}$. in 15 L reactor, initial pH 8) in waste nutrient solution from tomato hydroponic in green house condition. Results showed to remove 100% phosphate from the waste nutrient solution in the tomato hydroponics recorded over a period of 7 days. The growth rate of Nostoc HN601 was $16mg\;Chl-a\;L^{-1}$ in the waste nutrient solution from tomato hydroponics with optimum condition, whereas growth rate of Nostoc HN601 was only $9.8mg\;Chl-a\;L^{-1}$ in BG-11 media. Nitrogen fixing capacity of Nostoc HN601 was $20.9nmol\;C_2H_4\;mg^{-1}\;Chl-a\;h^{-1}$ in N-free BG-11. The total nitrogen and total phosphate concentration of Nostoc HN601 were 63.3 mg N gram dry weight $(GDW)^{-1}$ and $19.1mg\;P\;GDW^{-1}$ respectively. Collectively, cyanobacterial mass production using waste nutrient solution under green house condition might be suitable for recycling and cleaning of waste nutrient solution from hydroponic culture system. Biomass of cyanobacteria, cultivated in waste nutrient solution, could be used as biofertilizer.