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        검색결과 2,366

        1501.
        2013.11 서비스 종료(열람 제한)
        현재 국내에서 대부분 매립 또는 소각처리하고 있는 생활폐기물 및 사업장 폐기물 중에는 발열량이 높은 플라스틱, 종이와 같은 가연성폐기물이 많이 포함되어 있음에도 불구하고 유효한 에너지자원으로 활용되지 못하는 경우가 많다. 화석연료의 대부분을 수입에 의존하고 있는 우리나라는 신재생에너지(대체에너지)의 확보가 필수적이며 여러 종류의 재생에너지 중에서 폐기물에너지가 많은 부분을 감당해야 한다. 이를 위해 환경부에서는 폐기물을 에너지로 자원화하기 위해 고형연료제품화하는 정책을 시행하고 있고 이에 따라 국내 고형연료제품 제조시설이 확대되고 있는 상황이다. 고형연료제품 제조시설은 폐기물중에서 불연물을 선별하고 적정 발열량이 나오도록 건조하여 일정 품질의 연료가 되도록 만드는 시설이다. 이러한 시설은 일본과 유럽에서 먼저 설치・가동 되어 왔으나 국내에서는 이제 도입하고 있는 상황이기 때문에 그 기술에 대한 신뢰성이 의문시되어 시범사업을 우선적으로 하였다. 그러나 설계대로 성능이 나오지 않아 기술차이, 폐기물 물성차이. 폐기물 물성 조사방법 문제, 선진외국과의 단위장치 성능차이, 설비에 대한 투자비 문제 등 그 원인에 대한 다양한 논란이 제기되어 왔다. 보통 시설을 설계하려면 물질수지를 세워야 하고 물질수지를 세우기 위해서는 설치하고자 하는 시설특성에 맞게 폐기물에 대한 물성을 파악해야 한다. 그렇기 때문에 가장 먼저 해야 할 것이 폐기물 물성을 파악하고 이를 근거로 물질수지를 세워 설계하여야 하고 이러한 과정이 적합하다면 설치 후 목표로 하는 성능이 나와야 되는 것이다. 그러나 그 성능에 많은 논란이 되고 있는 상황에서 향후 고형연료제품 제조시설에 대한 설계기술을 선진화하기 위해서는 현재 운영되고 있는 시설에 대한 설계상의 물질수지와 운영상에 파악된 물질수지를 비교・분석하여 그 차이에 대한 원인를 파악하고 필요시 설계인자를 적용할 수 있어야 한다. 따라서 본 연구는 현재 운영되고 있는 고형연료제품 제조시설에 대한 물질수지를 세우는 방법론을 제시하는 것이 목적이다. 물질수지가 세워지면 각 단위장치의 특성에 따라 폐기물의 흐름 특성과 효율을 평가할 수 있고 또한 초기설계와 다르게 나오는 원인을 파악할 수 있으면 폐기물 물성자료와 실제 설계시 고려해야 할 인자를 유추할 수 있을 것이다.
        1502.
        2013.11 서비스 종료(열람 제한)
        본 연구는 3개소의 소형 고형연료 사용시설의 대기 배출특성을 분석하였다. 고형연료 사용시설은 RPF 사용 시설과 RDF 사용시설로 구분하였으며, 고형연료 품질특성, 입자상물질 배출특성, 가스상물질 배출특성, 다이옥신 배출특성 및 대기오염물질 배출 상관성분석, 배출원단위 특성을 바탕으로 다음과 같은 결론을 얻었다. 1. 고형연료제품의 RPF제품의 30개 시료의 발열량은 6,004kcal/kg ~ 10,153kcal/kg의 큰 편차를 보이며, 평균 7,846kcal/kg으로 조사되었다. RDF제품의 경우 11개 시료에서 3,065kcal/kg ~ 5,694kcal/kg으로 평균 4,526kcal/kg으로 조사되어, 연소조건의 안정을 위해서는 제품생산의 균질화가 필요한 것을 확인할 수 있으며, 대상시설 반입연료의 품질기준은 만족하나 3개시설 반입고형연료제품 발열량 변화폭이 큰 것으로 확인 되어 고형연료(SRF)를 통합할 경우 연소조건 및 대기오염물질 배출 변동 폭은 더 클 것으로 예상된다. 2. 주요 대기오염물질 배출특성을 살펴본 결과, 입자상물질의 경우 발생되는 양이 방지시설 전단 RPF의 A시설 423.61mg/Sm³, B시설 1223.18mg/Sm³, RDF의 C시설 973.4mg/Sm³ 이며, 보일러 출구 온도의 경우 온도가 높을수록 영향을 크게 받는 것을 확인할 수 있었으며, 온도제어가 오염물질 발생량을 줄일수 있는 방안으로 사료되었다. 가스상 물질의 경우 염화수소와 황산화물 농도가 다른 가스상 물질보다 높은 배출경향을 보이며, 특히 RPF사용시설이 RDF사용시설보다 높은 배출농도 특성을 보이는 것으로 확인되었다. 이는 발열량에 기인한 발생가스량과 밀접한 관계를 시사하며, 완전연소가 되도록 온도, 체류시간, 난류, 산소농도(T.T.T.O)가 조절되어야 하나 소형고형연료사용시설의 운전원이 전문적인 관리자가 아니기 때문에 일시에 다량투입 하는 등 불완전연소를 초래하여 일산화탄소 농도가 주기적으로 높게 배출되는 경향을 나타내고 있다. 3. 배출원단위 특성 검토 결과, 먼지를 제외한 황산화물, 질소산화물, 염화수소의 배출원단위가 국내 종규모 산정 적용 배출원단위 보다 높은 값을 보여 유지관리기준 마련에 세밀한 검토가 필요할 것으로 보인다. 주요 대기오염물질 배출 상관성특성 분석 결과, 대기오염물질 사이의 낮은 상관성을 보이는 것으로 나타났다.
        1503.
        2013.10 KCI 등재 서비스 종료(열람 제한)
        치매유발제인 알루미늄(aluminum, Al)에 대한 세포독성과 이에 대한 쇠비름(Portulaca oleracea L., PO)추출물의 영향을 배양 신경교종세포(C6 glioma)를 재료로 항산화 측면에서 조사하여 다음과 같은 결과를 얻었다. 본 연구에서 염화알루미늄(AlCl3)을 배양 C6 glioma세포에 처리한 결과 처리 농도에 비례하여 세포생존율을 유의하게 감소시킴으로서 세포독성을 나타냈으며 XTT50값이 100uM 이상으로 나타남으로서 중간독성(mid-toxic)인 것으로 나타났다. 한편, 항산화제인 vitamin E는 AlCl3에 의하여 감소된 세포생존율을 유의하게 증가시킴으로서 AlCl3에 의한 세포독성을 방어하였다. 한편, AlCl3의 세포독성에 대한 PO추출물의 영향에 있어서, PO추출물은 AlCl3에 의하여 감소된 세포생존율을 유의하게 증가시킴으로서 AlCl3에 의한 세포독성을 방어하였으며, 또한 superoxide dismutase (SOD)-유사활성(SOD-like activity)과 지질과산화(lipid peroxidation, LP)억제능 및 lactate dehydrogenase (LDH)활성 감소를 나타냈다. 이상의 결과에서 AlCl3의 세포독성에 산화적 손상이 관여하고 있으며 PO추출물은 AlCl3에 의한 세포독성을 항산화 측면에서 유효하게 방어하였다. 따라서 PO와 같은 천연추출물은 산화적 손상에 의하여 매개되는 치매와 같은 병변의 예방이나 치유를 위한 소재로서의 활용성이 클 것으로 생각된다.
        1508.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        While a range of natural organic matter (NOM) types can generate high levels of disinfection by-products (DBPs) after chlorination, there is little understanding of which specific compounds act as precursors. Use of eight model compounds allows linking of explicit properties to treatability and DBP formation potential (DBPFP). The removal of model compounds by various treatment processes and their haloacetic acid formation potential (HAAFP) before and after treatment were recorded. The model compounds comprised a range of hydrophobic (HPO) and hydrophilic (HPI) neutral and anionic compounds. On the treatment processes, an ozone oxidation process was moderate for control of model compounds, while the HPO-neutral compound was most treatable with activated carbon process. Biodegradation was successful in removing amino acids, while coagulation and ion exchange process had little effect on neutral molecules. Although compared with the HPO compounds the HPI compounds had low HAAFP the ozone oxidation and biodegradation were capable of increasing their HAAFP. In situations where neutral or HPI molecules have high DBPFP additional treatments may be required to remove recalcitrant NOM and control DBPs.
        1509.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        This study analyzed concentration and characteristics of hazardous substances in treatment of leachate from carcass burial areas by using high temperature thermal desorption (HTTD). Concentrations of pollutants emitted from HTTD treatment of leachate contaminated soil of carcass burial sites satisfied the emission standards for 11 pollutants from domestic waste incineration facilities. Dioxin concentration was 0.0060 ng I-TEQ/Sm3 and 0.0061 (0.0055-0.0070) ng ITEQ/ Sm3 in the normal operation condition and the experimental condition, respectively, which are much lower than the MSWI Standard of 0.1ng I-TEQ/Sm3. As a result, it was considered that leachate from carcass burial areas could be treated by high temperature thermal desorption (HTTD).
        1510.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        This paper analyzed thermal and carbonization properties of sewage sludge in fixed bed reactor and obtained following results. The heavy metal (Pb, Ni, Mn, Cr, Cu) content of Char showed the highest level at unprocessed sewage sludge, followed by carbonized sludge at 600, 400, and 500oC. It was thought to be mainly due to the yield of char rather than the influence of temperature. Also, the migration-test results of heavy metals satisfied the landfill directive in all samples, which may be possible to use it as landfill cover materials. The concentration of dioxin by changes of pyrolysis temperature was higher in the low temperature conditions and the proportion of PCDDs was higher than that of PCDFs.
        1511.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        This experiment was carried out for development of environment-friendly agriculture materials to control Bemisia tabaci (Gennadius) in eggplant. Plant growth investigated the spray at intervals of 7 days after transplanting on 8 environmentfriendly agriculture materials, such as egg-yolk and cooking oil, Results were to be good in the control and neem products. B. tabaci population density adult and nymph was low at the dinotefuran WG chemical treatment, and also low neem products of environment-friendly agriculture material. We have investigated the effect of different concentration of neem products on B. tabaci population density. Yield was high in the dinotefuran WG, and hight in the neem products and papper seed oil, but low in the sophora extracts and Ginko net sarcocarp. In the case of neem products treatment indicated 52 percent yield more than control.
        1512.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        사시나무의 클론간 생장 특성(전체 건중량, 줄기 건중량, 잎의 전체 건중량)과 대사물질간의 관계를 구명하여 조기선발을 위한 생장 관련 주요 인자를 구명하고자 사시나무 삽목묘(유묘)를 대상으로 우량클론과 일반클론간의 생장특성을 조사하였고, 수체내의 대사물질을 분석하였다. 사시나무 유묘의 줄기 건중량과 잎 내의 glucose, sucrose, inositol 등 당 함량과 정의 상관관계(p<0.05)가 있었으며, 잎의 건중량과는 줄기 내의 glutamic acid, alanine, threonine등과 같은 아미노산류의 함량과 정의 상관관계가 있었다. 사시나무 잎 내의 대사물질은 우량클론에서 glucose, sucrose, inositol 등과 같은 당류가 일반클론보다 고도의 유의 차이(p<0.01)가 있게 높게(1.3배 이상) 함유한 것으로 나타났으며,rythronic acid, malic acid, pentanedioic acid 및 proline도높게 함유한 것으로 나타났다. 또한 우량클론의 줄기내의 대사물질은 glutamic acid, alanine, threonine등과 같은 아미노산류의 함량이 일반클론에 비해 유의적으로 높게(1.2배 이상)함유하고 있는 것으로 나타났고, 더불어 succinic acid, maleicacid의 함량도 고도의 유의차이(p<0.01)로 우량클론에서 높게 함유하고 있었다. 생장이 우수한 사시나무 클론은 유묘의잎에서는 당류가 줄기에서는 아미노산류가 높게 함유하여 이러한 복합적 인자가 사시나무 우량클론 선발을 위한 대사 표지자의 개발에 필요한 기초 자료로 이용될 수 있을 것이다.
        1513.
        2013.08 KCI 등재 서비스 종료(열람 제한)
        Gastrodia elata Blume is a achlorophyllous orchid plant that has been used in traditional medicine to treat many human illnesses, such as vertigo, hemiplegia, and epilepsy. It contains three major pharmacological substances; gastrodin, ergothioneine, and vanillyl alcohol. Here we investigated the quantitative changes in those functional components by cultivation conditions and harvest times. The content of ergothioneine was different with cultivation areas, while gastrodin accumulated the higher levels than vanillyl alcohol regardless of cultivation areas. The smaller tubers contained the higher concentrations of gastrodin and the lower concentrations of ergothioneine than did the larger tubers. The cultivation under sun shade screen increased the concentrations of both gastrodin and vanillyl alcohol but decreased the levels of ergothioneine. We also determined the contents of functional substances depending on the harvest times. The concentration of gastrodin was higher in October than in April, while the level of ergothioneine was higher in April than in October. Interestingly, the use of sexually propagated seed tubers produced 1.9 times higher levels of gastrodin compared to vegetatively propagated seed tubers. In this study, we found that three major functional substances in G. elata tubers altered depending on various cultivation practices, which might be important to increase the economic values of G. elata tubers.
        1514.
        2013.07 KCI 등재 서비스 종료(열람 제한)
        We compared the applicability and economical efficiency of peroxone process with those of ozone process in the existing water treatment plant on downstream of Nakdong River. After comparing the peroxone process for removing geosmin with the ozone process in lab scale test, peroxone process showed much higher removal efficiency than the ozone process at the same ozone dosage. Proper range of H2O2/O3 ratio were 0.5~1.0 and the half-life of geosmin was about 5.5~6.8 min when the H2O2/O3 ratio was set to 0.5 during 1~2 mg/L of ozone dosage. Peroxone process could reduce the ozone dosage about 50 to maximum 30% for the same geosmin removal efficiency compared to the ozone process in the pilot scale test. In case of 1,4-dioxane treatment, peroxone process could have 3~4 times higher efficiency than ozone process at the same ozone dosage. The results of estimating the economical efficiency of ozone and peroxone process for treating geosmin and 1,4-dioxane by using pilot scale test, in case of the removal target was set to 85% for these two materials, the cost of peroxane process could be reduced about 1.5 times compared to ozone process, and in the same production cost peroxone process could have 2~3 times higher removal efficiency than ozone process. The removal efficiency by peroxone process showed a large difference depending on the physicochemical characteristics of target materials and raw water, therefore detailed examination should be carried out before appling peroxone process.
        1515.
        2013.07 KCI 등재 서비스 종료(열람 제한)
        Although antioxidant activities of Korean traditional fermented foods were reported by many researchers, study on antioxidant activity of microorganism originated from Korean traditional fermented foods was little. Therefore, we improved condition for antioxidant production by a bacterium isolated from home-made Chungkookjang. We selected a bacterial strain, which showed the highest antioxidative activity, from Chungkookjang and then named GJ. The selected GJ strain was identified as Bacillus methylotrophicus by alignment data of 16S rRNA gene nucleotide sequences. Improved medium compositions for DPPH radical scavenging activity were 0.25% sucrose, 1% peptone, 0.01% MgSO4·7H2O and initial pH 6.5, respectively. Optimal culture conditions were 30℃, 200 rpm and 4% inoculum volume, respectively. In improved conditions, DPPH radical scavenging activity of GJ reached to 91% in a short time. The strain GJ also possessed ACE inhibition and other antioxidative activities; ACE inhibition activity (49.4%), ABTS radical scavenging activity (99.8%), metal chelating activity (67.9%), SOD-like activity (36.5%) and reducing power (A700 = 5.982) were observed, respectively. Therefore, our results suggest that B. methylotrophicus GJ strain may be potential candidate for functional foods, cosmetic products for anti-aging and medicine for diseases caused by oxidative stress.
        1516.
        2013.07 KCI 등재 서비스 종료(열람 제한)
        Emissions of air pollutants and greenhouse gases (GHGs) from aircraft activities at 11 small-scale airports were investigated using the emissions and dispersion modeling system (EDMS) version 5.1.3 during the two year period of 2009~2010. The number of landing and take-off (LTO) at these airports was dominant for the aircraft type B737, accounting for more than 60% of the total LTOs. Out of the 11 small-scale airports, Gwangju (GJ, RKJJ) airport was the largest emitter of air pollutants and GHGs, whereas Yangyang (YY, RKNY) airport was the smallest emitter. The emissions of NOx and VOCs in 2010 at the 11 airports ranged from 1.9 to 83 ton/y and 0.1 to 17 ton/y, respectively. In 2010, the emissions of CO2 ranged from 394 to 21,217 ton/y. The emissions of most air pollutants (except for NOx and PM10) and GHGs were estimated to be the highest in taxi-out mode. The highest emissions of NOx and PM10 were emitted from climb-out and approach modes, respectively. In addition, the total LTOs at the 11 small-scale airports accounted for the range of 9.3~9.9% of those at four major international airports in Korea. The total emissions of air pollutants and GHGs at the 11 airports ranged from 4.8 to 12% of those at the four major airports.
        1517.
        2013.07 KCI 등재 서비스 종료(열람 제한)
        Difference in immobilization effect of heavy metal-contaminated soil between two different amendment methods was evaluated; 1) both of steel slag (i.e., consisted in solid phase) and soluble phosphate (i.e., consisted in liquid phase) were simultaneously applied to contaminated soil (i.e., simultaneous amendment methods) and 2) soluble phosphate and steel slag was applied sequentially to the contaminated soil (i.e., sequentially amendment methods). The application rate of stabilizers to soils was determinated based on weight/weight ratio of 5% for steel slag and PO4/Pb molar ratio of 2.0 for phosphates, respectively. To identify difference of immobilization effect to test soil, three different soluble phosphates, such as Na2HPO4·12H2O, Ca(H2PO4)2·H2O and (NH4)2HPO4 were used. The sequential amendment was 6 ~ 27% more effective than the simultaneous amendment in terms of the immobilization efficiency for Pb, Cu, and Cd in the contaminated soil. There was little difference in case of Zn. Among the three phosphates tested, (NH4)2HPO4 was clearly the most effective. Residual form of heavy metals concentration in sequentially methods is higher than those in simultaneously methods. At the same time, more exchangeable and carbonate-bound forms of heavy metals in simultaneously methods were observed than in sequentially case. These result implies that the sequential amendment method was more effective than the simultaneous amendment method in terms of heavy metal immobilization in the contaminated soil.
        1518.
        2013.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This study was performed to investigate the four-week repeated-dose toxicity of the crude antifungal compounds produced by Lactobacillus plantarum AF1 (Lb. plantarum AF1), a lactic acid bacterium isolated from kimchi, in male and female rats. Sprague-Dawley male and female rats were divided into four groups, with 10 animals in each group. The test article was administered once daily by gavage to rats at dosage levels of 0, 500, 1,000, and 2,000 mg/kg/day for four weeks. There were no test-article-related deaths or abnormal clinical signs in both the male and female rats during the observation period. Furthermore, no differences in the body weight changes, food intake and water consumption levels of the control and treatment groups were found. The hematological parameters, serum biochemical analysis results, histopathological examination results and all other findings also showed no significant or dose-dependent changes. There were also no changes in the organ weights upon the administration of the crude antifungal compounds produced by Lb. plantarum AF1. These results suggest that the oral administration of the crude antifungal compounds produced by Lb. plantarum AF1 had no adverse effects up to a dosage level of 2,000 mg/kg in both male and female rats.
        1520.
        2013.04 KCI 등재 서비스 종료(열람 제한)
        This study was to investigate the runoff characteristics of non-point pollutants source at the urban area in Suwon city. The highest T-N and T-P concentration of rainfall runoff observed in agricultural area. In residential area, the highest BOD5 and SS concentration of rainfall runoff was investigated. During rainfall events, the peak concentrations of SS and BOD5 were observed after 1~2 hours of rainfall in urban area. Whereas, the peak concentrations occurred within 1~2 hours after rainfall and then the highest concentrations of SS and BOD5 sharply decreased, showing strong first flush effect in urban area. The EMC results indicated that the highest value of T-N and T-P in agricultural area was observed. While residential area was shown the lowest EMC value as T-N and T-P. Non-point pollutant loads on the land use types in urban area were investigated in the order of residential>industrial>agricultural>highway. BOD5 and SS loads on urban watershed were investigated in the order of Suwon>Hwangguji>Seoho>Wonchunri. Whereas, T-N and T-P loads on urban watershed were investigated in the order of Hwangguji>Suwon>Wonchunri>Seho.