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        검색결과 95

        61.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        Recently, production of sewage and wastewater sludge have increased sharply with the population density and related industrial activity. As a result, studies of sludge treatment and reduction have been conducted and a pre-treatment method that uses thermal hydrolysis has emerged as a solution to this problem. To address problems with the thermal hydrolysis pre-treatment process, the deaeration and nitrogen recovery processes have been set up together, thus generating factors that inhibit dewaterability. In this study, the effect of pre-treatment, deaerated sludge on dewaterability-inhibiting factors (pH, temperature, aeration rate) was evaluated and alternative solutions were prepared. First, the dewaterability improvement effect increased rapidly at 190°C or higher when thermal hydrolysis pre-treatment was applied. Then, 1 L of thermal hydrolysis pre-treatment reactants at 190°C were injected into 1, 5, and 10 L/min air flows at 50°C, but no significant difference in capillary suction time (CST) or time to filter (TTF) was found. The dewaterability improved when the temperatures of the pre-treatment reactants varied between 30, 50, and 70°C under aeration at 5 L/min. However, when the pH was increased to 7, 9, or 11 at 5 L/min and 50°C, the dewaterability worsened by at least 10 times relative to the hydrolysis pre-treatment reactants. The zeta potential decreased from -30 mV to -50 mV as the pH increased. Thus, the stabilities and dispersities of the reactants increased due to the repulsive force of the particles. This was confirmed to be the cause of poor dewaterability. A coagulant can be used to solve to this problem, or the deaeration process can be placed after solid-liquid separation and the heat of thermal hydrolysis can be extracted via heat exchanger.
        62.
        2016.11 서비스 종료(열람 제한)
        산업혁명 이후 대기 중의 온실가스 중 하나인 이산화탄소가 증가하면서 전세계적으로 지구온난화가 화두되고 있다. 이산화탄소 저감기술인 CCS(Carbon Capture and Storage) 기술은 이산화탄소를 포집 후 저장하는 기술로 저장의 한계에 따라 CCU(Carbon Capture and Utilization) 기술이 각광받고 있다. CCU는 이산화탄소를 이온화 하여 무기 혹은 유기재료로 전환이 가능하다. 폐기물의 금속이온을 이용하여 화학적으로 무기탄산화가 가능하며, 폐기물과 이산화탄소를 동시에 처리할 수 있다는 이점이 있다. 본 연구에서는 최종산물을 탄산칼슘을 생성하는 것이며, 탄산칼슘의 수율을 증대시키기 위해서는 폐기물 내의 칼슘 이온의 추출효율을 올리는 것이 중요하다. 하지만 용매를 이용할 경우 칼슘이온 외에 다른 이온들도 같이 추출되면서 탄산칼슘의 순도를 떨어뜨린다. 이에 최종생성물의 순도를 높이기 위하여 칼슘이온만 선택적으로 추출하기 위해 실험을 진행하였다. 실험에 사용된 폐기물은 탈황석고와 폐시멘트를 이용하였으며, 칼슘이온을 선택적으로 추출한 샘플을 이용하여 탄산화반응을 통하여 탄산칼슘을 생성하였다. 생성된 탄산칼슘은 XRD (X-ray diffraction analyzer(Ultima Ⅳ))와 FE-SEM(Field emission scanning electron microscope, JEOL-7800)를 통하여 결정구조를 분석하였다.
        63.
        2016.07 KCI 등재 서비스 종료(열람 제한)
        In this paper, tin-waste resources were pulverized and separated by cut-mill and multi cyclone separator, respectively. After the cut-mill process, more than 98% of the Pb-Sn and Sn-Ag-Cu scraps were recovered, and the by-products consisting of metal and oxide could be reused as solder. The separation of pulverized powders was performed using the minimum fluidization velocity depending on the density of the materials. When the flow rate was 21 L/min (70% blower output), it had the highest separation efficiency.
        64.
        2016.04 KCI 등재 서비스 종료(열람 제한)
        The dewaterability of pig manure by heat pre-treatment was evaluated in this study. The specific resistance coefficient, a dewatering characteristic, was measured by time to filtration (TTF) test. The experimental conditions were set for heat treatment: 15, 30, 60, and 120 min at 120 ± 1oC and 16, 30, and 60 min at 135 ± 1oC, respectively. The specific resistance coefficient of pig manure was found to be 9.204 × 1011m/kg before treatment, and it gradually decreased with high temperature and long treatment time. Moisture content was decreased from 88% to 77% by heat pre-treatment, and its efficiency was better than mechanical solid-liquid separation with chemical addition. In addition to increased dewaterability, TOC (Total Organic Carbon) concentration was decreased for about 15-42%. Nitrogen concentration was also decreased due to conversion of NH4 +-N to NH3 gas by increased treatment temperature. Consequently, heat pre-treatment was effective for decreasing moisture content and organic matters, and it could have potential for nitrogen recovery.
        65.
        2016.02 KCI 등재 서비스 종료(열람 제한)
        In this study, we have investigated to find optimal pre-treatment flocculation condition by analyzing the floc growth rate with mixing conditions and the membrane permeation flux for pre-treatment step of the membrane process. The higher mixing intensity showed a constant floc size index (FSI) values, and lower mixing intensity increased the degree of dispersion of the FSI values. Results of comparing the distribution characteristics of the FSI value and the permeation flux were more effective in increasing flux when the FSI values were 0.2 or higher. The degree of dispersion of FSI was relatively large in 40 rpm mixing condition compared to 120 rpm. In 40 rpm mixing condition, it decreased the permeation flux compared to 120 rpm because various sizes of flocs were distributed. Coagulation-UF membrane process enhanced 30%∼40% of the flux rate compare to UF alone process, and the coagulation-MF process increased up to 5% of the flux rate compare to MF alone process. Pre-treatment, that is, coagulation process, has been found to be less effects on relatively larger pore size for MF membrane. For UF membrane, the flux was a little bit same when applying only the rapid mixing process or rapid mixing with slow mixing processes together. In case of MF membrane, the flux was improved when rapid mixing process applied with slow mixing process together.
        66.
        2015.08 KCI 등재 서비스 종료(열람 제한)
        절화 백합‘Siberia’의 수확 후 수명 연장과 품질 향상을 위해 1-MCP의 효과적인 처리 농도, 시간 및 온도를 구명하기 위해 수행하였다. 개화 단계는 모든 처리별 5°C처리가 개화지연 효과가 가장 좋았으며, 특히 5°C조건에서 1.5mg·L-1 1-MCP를 1시간 처리시 다른 처리구에 비해 개화 단계가 지연되었다. 잎의 엽록소 함량은 모든 처리구가 대조구보다 다소 높은 엽록소 함량을 유지하였으며, 5°C조건에서 1.5mg·L-1 1-MCP를 1시간 처리시 높은 함량을 나타내었다. 생체중은 대조구가 5일부터 감소되는 반면 5°C 조건에서 1.5mg·L-1 1-MCP 전처리를 1시간동안 하였을 때 11일까지 증가되었다. 수분흡수량에서는 대조구가 실험 종료일까지 꾸준하게 감소하는 반면 15°C조건에서 3.0mg·L-1 1-MCP를 0.5시간 처리시 가장 높은 흡수량을 나타내었다. 수분균형은 무처리시 7일부터 (-)값으로 급격히 떨어지는데 비해 대부분의 1-MCP 처리구는 9일부터 서서히 (-)값으로 떨어지고, 특히 5°C조건에서 1.5mg·L-1 1-MCP 1시간 처리구는 11일까지 유일하게 (+)값을 유지하는 결과를 나타내었다. 각 전처리별 조사 초기 색상 변화에서는 5°C조건에서 3.0mg·L-1 1-MCP를 0.5시간 처리시 녹색값이 비교적 높게 유지되었으며, 절화수명 및 절화 품질에 있어서는 5°C조건에서 1.5mg·L-1 1-MCP를 1시간 처리시 19일로 가장 연장되는 효과를 나타내었다. 박테리아 발생량은 5°C조건에서 1.5와 3.0mg·L-1 1-MCP를 1시간 처리시 가장 낮은 발생량을 나타내었다. 에틸렌 발생량 및 호흡률은 대조구보다 낮은 발생량을 나타내었으며, 특히 15°C조건에서 3.0mg·L-1 1-MCP를 1시간 처리시 다른 처리에 비해 낮은 양상을 나타내었다. 이상의 결과를 종합적으로 고찰해보면 5°C조건에서 1.5mg·L-1 1-MCP를 1시간 처리시 도관의 미생물 발생 억제 효과가 지속적으로 작용하여 수분 흡수가 원활히 이루어짐으로써 수확 후 절화 백합의 선도유지 및 품질에 매우 효과적임을 알 수 있었고, 수출저장유통 과정 중에 상용적인 기술로 사용 가능함을 제시 할 수 있었다.
        67.
        2015.07 KCI 등재 서비스 종료(열람 제한)
        Municipal Solid Wastes (MSW) are disposed of three types (recycling, incineration, landfill). The ashes made after the incineration are also recycled to minimize the volume of waste owing to reducing the amount of landfill. However, MSW incinerations (MSWI) in Seoul are not satisfied with the policy of Korea as a result of experiments about the chemical characteristics of the ash (Ignition loss, pH, Chloride, Cyanide, metals leaching). So, according to the policy, the MSWI in Seoul must be pretreated so as to recycle the MSWI. There are many pretreatments, three pretreatments (washing, weathering, CO2 aging) of which are selected through the literature review. Through Washing, the value of pH and chloride decrease. The optimal ratio (S/L) and time of Washing treatment is 1 : 10 (S/L) and 60 minutes, respectively. The CO2 aging method compensates the defect of weathering method which is required to react long-period time. After CO2 aging, pH and some Heavy metals decrease. So, We will compare and evaluate pre-treatment methods and we find the best method or new method.
        68.
        2015.05 서비스 종료(열람 제한)
        In this study, enhancement of phosphorus and nitrogen recovery efficiency from livestock manure through Magnesium Ammonium Phosphate (MAP) crystallization method has been suggested as an alternative to solve the problems of the existing phosphorus resource recovery method. It can become a useful fertilizer. This study focused on improvement of phosphorus resource recovery by changing energy density of ultrasonic dose for MAP crystallization. Solubilization rate (as phosphate/phosphorus) of phosphorus in livestock manure was measured by ultrasonic treatment. The energy density range of 100-50,000 of ultrasonic dose was determined. Optimal ultrasonic energy density was 1,000 dose as 64.5% of phosphate ratio. However, when the higher than 1,000 dose of ultrasonic energy density did not more improve phosphate solubilization ratio. Consequently, when use ultrasonic treatment at 1,000 dose of energy density, the phosphorus could recover approximately 65% from livestock manure by MAP crystallization. Moreover, this MAP becomes more valuable due to its nature as a slow-release fertilizer.
        69.
        2015.05 서비스 종료(열람 제한)
        Livestock wastewater has high potential as one of energy resources because this wastewater is including high organic matter. Therefore the studies attempting to bio-gasification and bio-electricity generation using livestock wastewater is being tried. The pre-treatment system used in this study was the purpose to control the ammonia nitrogen in conjunction with the system and the microbial fuel cell. Because ammonia nitrogen is to inhibit the electricity generation efficiency of microbial fuel cell. These studies were to ascertain the effect of oxidants on the nitrogen removal in the pre-treatment system using catalyst and microbubbles to treat the ammonia nitrogen. The three kinds of oxidant such as air, oxygen (O2), and hydrogen peroxide (H2O2) were used to know the ammonia and nitrate nitrogen removal. This system was operated with four kinds of conditions. First method is O2 gas with 100 mL/min with 1ml of 30% H2O2 was supplied to the wastewater. A second method, the O2, with 400 and 1,000 mL/min was supplied through the flow meter before livestock wastewater was flow in the reactor. The last method, air was supplied 800 mL/min. The nitrate removal had no significant difference all conditions except the air supply. On the other hand, the ammonia and nitrate nitrogen removal when oxygen was supplied with 1000 mL O2/min was higher than that of the other conditions. The removal rate when air was supplied 800 mL/min was similar to the value in the supplied with 400 ml O2/min. This result showed that oxidant was important factor to improve the ammonia nitrogen removal rate.
        70.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to investigate the effect of pre-germination soaking on germination in 90 Korean soybean varieties and identification of protein in seeds of 7 soybean varieties. The results obtained that germination rate of soybean seeds was decreased as amount of soaking water and soaking duration in number of days. Difference in germination rate of soybean seeds was significant at three days soaking with water volume of 90 ml. Water absorption of seeds was rapidly increased during the first 6 hours, followed by slow increase until 24 hours and then decreased 24 to 48 hours after soaking soybean varieties for bean sprout soaked the lowest amount of water, while soybean varieties for cooking with rice showed the lowest seed water content. Dissolved oxygen (DO) in soaking water was rapidly decreased during the first 3 hours after soaking, and then slowly decreased. Soybean varieties for vegetable and early maturity showed the lowest DO during early soaking periods, but showed higher DO after 24 hours than other groups of soybean varieties. Electrical conductivity and Total Dissolved Solid (TDS) were increased as number of soaking days increased. Soybean varieties for vegetable and early maturity showed the highest electrical conductivity and TDS, followed by those for sauce and paste or cooking with rice, while showed the lowest electrical conductivity and TDS, varieties for bean sprout. Among 90 Korean soybean varieties, varieties which showed the highest germination rate were Jangsu-kong for sauce and paste, Sobaegnamul-kong for bean sprout, Seonheuk-kong for cooking with rice, Seunnokkong for vegetable and early maturity. On the ather hand varieties which showed the lowest germination rate were Iksan and Songhak-kong for sauce and paste, Pangsa-kong for bean sprout, Jinyeul-kong for cooking with rice, Sinlok-kong for vegetable and early maturity. Germination rates of soybean seeds were higher when electrical conductivity, TDS and water absorption of seeds were lower. There were negative correlations between electrical conductivity, TDS and water absorption of seeds and germination rate, while there were positive correlations among electrical conductivity, TDS and soybean seed weight.
        71.
        2014.12 KCI 등재 서비스 종료(열람 제한)
        절화 국화 ‘백설’의 상온 및 5℃ 저장시 Promalin 50mg.L-1 처 리는 절화 후 초기 개화를 억제시키고 품질을 증진시키는 좋은 작 용을 함을 알 수 있었다. 이러한 효과는 상온 저장시 더욱 효과적이 었으며 상품성 손실과 관계되는 생체중 유지에 작용하여 선도유지 에 좋은 전처리제임을 확인할 수 있었다. 또한 Promalin 50mg.L-1 분무 전처리는 절화 국화의 에틸렌 발생을 억제시키는 경향을 나타 내었으며 호흡급등형 패턴을 나타내고 있음을 알 수 있었다.
        72.
        2014.12 KCI 등재 서비스 종료(열람 제한)
        절화국화 ‘Yes Song'의 이산화염소 전처리가 선도유지 및 품질 을 조사하였다. 개화 단계는 대부분의 처리구에서 수확 후 8일까지 급속히 개화하였고, 특히 BA 25mg.L-1 + ClO2 5mg.L-1 + NaClO 200mg.L-1 처리구에서 비교적 선도가 유지되었다. 생체중 변화는 모든 처리구에서 5일까지 증가하였으나, 이후 감소하는 경향을 나 타내었고 BA 25mg.L-1 + ClO2 5mg.L-1 + NaClO 200mg.L-1 처리 구가 다른 처리에 비해 높은 생체중을 유지하였다. 수분 흡수량은 대부분의 처리구에서 5일까지 증가하다 이후 감소 추세를 보였으 며, 특히 ClO2 5mg.L-1 처리는 다른 처리구에 비해 현저히 증가하 였다. 수확 후 잎의 엽록소 함량은 BA 25mg.L-1 + ClO2 5mg.L-1 + NaClO 200mg.L-1 처리시 높은 수준을 유지하였다. 꽃잎의 화색변 화에서는 BA 25mg.L-1 처리시 화색변화를 가장 오래 지연시켰다. 에틸렌 발생량은 초기 3일째는 급속히 증가하다가 그후 비교적 완 만한 경향을 보였으며 처리별로는 BA 25mg.L-1 + ClO2 5mg.L-1 + NaClO 200mg.L-1 처리구에서 가장 적은 발생량을 나타내었으며, 절화 수명 및 절화 품질에 있어서도 BA 25mg.L-1 + ClO2 5mg.L-1 + NaClO 200mg.L-1 처리시 다른 처리에 비해 8일정도 증가되는 결과를 나타내었다. 이상의 결과를 종합적으로 고찰해보면 BA 25mg.L-1 + ClO2 5mg.L-1 + NaClO 200mg.L-1 처리구에서 도관 의 미생물 발생 억제 효과가 지속적으로 작용하여 수분 흡수가 원 활히 이루어짐으로써 수확 후 절화 국화의 선도유지 및 품질에 매 우 효과적임을 알 수 있었고, 수출저장유통 과정 중에 상용적인 기 술로 사용 가능함을 제시 할 수 있었다.
        74.
        2014.02 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to determine the effects of seed storage temperature and pre-treatment on seed ger-mination, seedling quality and vigor index of wild Trichosanthes kirilowii and Trichosanthes kirilowii var. japonica. As a resultthe highest germination rate of T. kirilowii was the 95% at seed stored in room temperature and then soaking for 24 hours indH₂O. And the highest germination rate of T. kirilowii var. japonica was 96% at seed stored in 2℃ and then soaking for 24hours in GA₃(100ppm). But the seed germination rate was non-significance in pre-treatment at seed stored in roomtemperature 2℃ .Seedlings of T. kirilowii and T. kirilowii var. japonica showed not only the best seedling quality but alsoseedling vigor index in seed stored at 2℃ and then soaking for 24 hours in GA₃(100ppm). In this research, T. kirilowii and T.kirilowii var. japonica seed were stored in room temperature or 2℃, and then sown in peat moss, seed germination rate wasmore than 90% and production of superior quality seedlings.
        75.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        In this study, the effect of hydrogen peroxide (H2O2) pre-treatment for sewage sludge prior to anaerobic digestion wasassessed using a batch test with an objective to decrease nitrogen, dissolved sulfide and siloxane in sewage sludge. Atotal of 6 sets of experiments (Blank, 20, 40, 60, 80 and 100g H2O2/kg wet sludge) were carried out, each with duplicates.To assess the effect of different dosages of H2O2 on anaerobic digestion, the treated sewage sludge was used for biochemical methane potential (BMP) test and SCODcr concentration. Due to the H2O2 pre-treatment, solubilization of SCODcr in pretreated sludge increased by 89% compared to raw sewage sludge, whereas T-N and NH3-N concentrationdecreased. Cumulative methane yields were increased for all pretreated samples due to increased sludge solubilizationthrough H2O2 pre-treatment. In addition, dissolved siloxane concnetrations were decreased for all pretreated samples. Thus,a reduction in dissolved siloxane concenrtation can decrease the siloxane generation potential of sludge during anaerobicdigestion. However, dissolved sulfide concentration remained same. Although H2O2 dosage did not show any furtherimpact on dissolved sulfide, they have significantly decreased T-N, NH3-N and dissolve siloxane concentrations beforeanaerobic digestion.
        76.
        2013.10 KCI 등재 서비스 종료(열람 제한)
        본 연구는 스프레이 절화 국화 ‘레오파드’를 수확 후 일본으로 수출 시 저장온도 및 전처리제가 선도유지에 미치는 영향을 알아보고자 수행하였다. 수출국으로 수송시 수확 후 3일째 수송온도 5℃에 저장한 처리구가 상온에 비해 개화가 늦게 진행되었다. 절화수명은 NaOCl 전처리 후 수송온도 5℃에 저장한 처리구가 상온 무처리구에 비해 7일이 연장되었다. 생체중 변화율은 상온의 수송온도 처리구가 5℃에 비해 더 높은 것으로 조사되었다. 엽록소 함유량은 BA 전처리 후 수송온도 5℃에 저장한 처리구가 상온 무처리구에 비해 처리구가 다른 처리구들에 비해 많은 것으로 조사되었다. 따라서 스프레이 절화 국화 ‘레오파드’를 수확 후 NaOCl처리가 효과적인 것으로 판단되며, 5℃로 수송하는 것이 절화의 품질을 유지하며, 노화를 지연시킬 수 있을 것으로 판단되었다.
        78.
        2013.04 KCI 등재 서비스 종료(열람 제한)
        This study, changes in raw water quality is to indicate on the efficiency of ozone treatment of each pollutant as compared to derive the appropriate operating measures. The appropriate selection for injection rate of pre-ozone and did not inject pre-ozone assess changes in the water. When good water quality, you not injected of pre-ozone to evaluate the economic efficiency of electricity and put the most cost-effective ozone concentration were evaluated. Evaluation remove organic matter and chlorophyll-a concentration level in experiments with each factor of the water DOC> 2.5 ㎎ / L, THMFP> 70 ㎍ / L, Chl-a> 30 ㎎/ ㎥or less constant process, if you do not need to put pre-ozone showed little impact. It also does not put you in pre-ozone appropriate produce enough power rate savings was calculated as approximately 90 million won. Ability to remove organic materials and the ability to produce disinfection byproducts, and cost-effective decisions by considering the concentration of injection if pre-ozone 1 mg/L was investigated by the appropriate concentration of ozone injection.
        79.
        2013.03 KCI 등재 서비스 종료(열람 제한)
        This research study was to develop methods for inhibiting the germination of cotton seeds. Germination rates after heating treatment at 80℃ with 10, 20, 30, 40 min. were 9.3, 9.3, 5.3 and 1.3 percentage, respectively. Heat treatment over 85℃ with 10 min. caused no germination of cotton seeds. Germination was significantly reduced with gamma rays treatment more than 10,000 gy, while the treatment within 2,000-8,000 gy induced less effects. Microwave processing for 30 seconds and 60 seconds inhibit the germination of cotton seed under 8 and 0%, respectively. As a physical treatment, rollmill milling with 1.5, 2, 2.5 mm gap inhibited any germination of cotton seeds. The optimum gap of roll-mill for processing physical cracking was below 51% of the thickness of seed.
        80.
        2013.02 KCI 등재 서비스 종료(열람 제한)
        본 연구는 점차 사라져가는 큰조롱의 유전자원을 보호하고 이용하고자 종자 발아 기술과 육묘기술 개발을 위해 종자 침지 처리 온도, GA3 농도, 트레이 및 토양 종류, 차광처리에 따른 큰조롱의 발아율과 생육특성을 조사하였다. 종자발아는 20℃에서 GA3 100 ppm에 침지한 처리구에서 가장 높은 93% 발아율을 보였다. 묘소질 특성은 50구 트레이에서 가장 뛰어났으며 생리적 묘소질 특성은 20℃에서 GA3 10 ppm에 침지 처리 한 종자를 TKS 토양이 충진된 128구 트레이에 파종한 조건에서 가장 뛰어났다. 따라서 큰조롱의 묘소질과 생리적 묘소질을 종합하고 경제적인 측면을 고려하면 128구 트레이 혹은 200구 트레이의 TKS, TKS+펄라이트 및 TKS+왕겨 처리구에서 4월 중순에 파종 후 30~ 45일 간 육묘하면 초장과 근장이 각각 10 cm 이상되고 엽수가 8 매 이상 되는 우량한 묘를 획득할 수 있었고 이를 본 밭에 이식이 가능한 것으로 보여진다.
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