• 식물병연구
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• 제13권3호
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• pp.157-163
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• 2007

본 연구는 유기농 채소종자의 소독방법으로 가장 적합한 온탕침지법을 개발하고자 수행하였다. 엽채류 중 열에 비교적 민감한 상추 종자의 최적 온탕침지 조건은 $45^{\circ}C$ 25분이었으며 배추와 무 종자 $50^{\circ}C$ 25분이었다. 온탕침지로 이들 종자의 발아율과 생장은 무처리와 비슷하거나 촉진되었고, Alternaria, Aspergillus, Penicillium, Mucor 등의 종자감염 곰팡이는 90% 이상 혹은 100% 억제되었으며 상추 종자에 감염된 세균 억제효과는 98.5%였다 오이, 고추, 호박 등 과채류 종자 중에는 호박이 가장 온수에 감수성이었는데 $50^{\circ}C$ 15분 침지가 적합하였고 오이와 고추 종자는 $50^{\circ}C$ 25분 처리가 가장 효과적이었다. 온탕 침지한 오이 및 호박 종자의 발아율 및 생장은 무처리와 비슷하거나 약간 높았는데, 고추의 경우에는 발아율은 50% 이상 증가되었으며 뿌리생장은 5배 이상 신장되었다. 이들 종자에 감염된 곰팡이 중 Rhizopus, Aspergillus, Penicillium, Mucor등의 억제율은 $72%{\sim}95.4%$였고 감염세균의 억제율은 $65.5%{\sim}86.0%$였다. 본 시험의 결과로 볼 때 온탕침지의 최적 조건은 종자에 따라 다소 다르며, 온탕침지는 모든 종자전염성 병원균을 방제할 수는 없으나 이들을 효과적으로 억제할 수 있는 기술로 유기농업에서 유용하게 활용할 수 있을 것으로 기대된다.

• 상하수도학회지
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• 제25권5호
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• pp.777-782
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• 2011

The residual treatment facilities in WTP(water treatment plant) play an important role in solid-liquid separation. At present, it is difficult to solve problems related with thickening and dewatering of WTP sludge, and discharging waste water to river. The quantity of residuals generated from water treatment plants depends upon the raw water quality, dosage of chemicals used, performance of the treatment process, method of sludge removal, efficiency of sedimentation, and backwashing frequency. Sludge production by the physical separation of SS(Suspended Solid) occurs under quiescent conditions in the primary clarifier, where SSs are allowed to settle and to consolidate on the clarifier bottom. Raw primary sludge results when the settled solids are hydraulically removed from the tank. In this study, Drawing characteristics of the sludge thickening in the thickener of Water Treatment Plants was simulated by Using CFD(Computational Fluid Dynamics.

• 한국토양비료학회지
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• 제34권3호
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• pp.153-157
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• 2001

To evaluate the effect of liquid pig manure application, the growth and yield of rice and the quality of infiltration water were investigated with application of different amounts of liquid manure. At this study, liquid pig manure was treated with 100, 200, 300 and 400% of recommending nitrogen fertilizer level, respectively. Liquid manure with application rate more than 200% of recommending N fertilizer level (11kg) caused to increase of plant height and number of tiller at panicle formation stage, but it caused the plant disease and pest and plant lodging. In those treatment, number of panicles per hill and number of spikelets per panicle were increased, but yield of rice was less than chemical fertilizer treatment due to low rate of ripeness and 1,000 grain weight. $NO_3-N$ concentration in infiltration water sample collected at 90 cm of soil depth was increased with increasing application amount of liquid manure. With liquid manure application more than 200% of recommending N fertilizer level, it affected negatively on yield and environment such as groundwater quality.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 추계학술논문요약집
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• pp.390-391
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• 2018

• 환경위생공학
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• 제5권1호
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• pp.83-92
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• 1990

Adapting two step aeration system to a waste water treatment of W-paper manufactory as Full-Scale Plants, we drew a following conclusion from its practical working. 1. Because BOD removal efficiency was 20% in A-Stage, 90% in B-Stage and total removal efficiency was 97%. It worked treatment plant well and was suitable for effluent water standard as well. Because COD removal efficiency was 42% in A-stage, 71% in B-stage and the total removal efficiency was 94% COD control was possible in effluent water quality. 2. Treatment efficiency according to a load capacity was average 20% in 1.401 BOD kg/m3/d load of A-Stage and average 90% in 0.273 BOD kg/$\textrm {m}^3$ / d load of B-Stage. 3. Treatment efficiency according to a ratio of F/M was 2.657--5.024 kg BOD/kg MLSS/d in A-Stage and BOD removal efficiency was 16-261 in the same stage. The ratio of F/M was 0.068-0.094 kg BOD /kg MLSS/d and BOD removal efficiency ratio was 85-94%. Therefore treatment efficiency could be kept stably and volume of aeration tank could be reduced wholly. 4. Treatment efficiency according to MLSS appeared BOD 20%. COD 42%, in A-Stage and removal efficiency appeared BOD 90%, COD 71% in B-Stage. They were suitable for plan condition. 5. Because of working of complemented treatment plant by AB-Process. 20,000,000 Won a month was saved than the ordinary working cost. Therefore, it was assumed that invested cost could be recollected in 19 months or so consequently.

• 한국물환경학회지
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• 제28권6호
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• pp.851-858
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• 2012

This study conducted a result analysis on operation of 26 Rural Community Sewage Treatment Plant (RCSTP) newly constructed in Yeong-yang, Bong-hwa and An-dong areas which are located at the upper region of An-dong Dam and Im-ha Dam. Based on operation result, an analysis on characteristics of sewage in each area and the treatment efficiency of the installed treatment process was conducted. The result of analysis on characteristics of sewage has shown the difference in concentration of the sewage according to area characteristics. Sewage in areas with frequent occurrence of agricultural water and livestock wastewater had high concentration. It is important to select the most suitable treatment process when selecting a treatment process for RCSTP according to properties of sewage in each area. As a result of operation, the disposal efficiency for organic matter and suspended solids was stable with less fluctuation, but the disposal efficiency for nitrogen and phosphorus showed high fluctuation. This signifies that it is necessary to pay attention to operation condition management of nitrogen and phosphorus when operating RCSTP.

• 한국초전도ㆍ저온공학회논문지
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• 제13권2호
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• pp.21-24
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• 2011

Superconducting high gradient magnetic separation (HGMS) has advantages to treat wastewater because it can generate high magnetic field and achieve rapid purification. In this study superconducting HGMS was applied to remove impurities from the condenser water in thermal power plant. The condenser water contained mainly hematite and maghemite and it was highly magnetized than hematite. In the HGMS tests using a 6-T cryo-cooled Nb-Ti superconducting magnet, the turbidity of the condenser water was effectively reduced up to 99.6% and the result showed better performance than that of the 0.5-T permanent magnet test. The higher magnetic field was applied in the range of 1-6T, the more iron oxides were removed. The effect of magnetic filter configuration on the condenser water treatment was also investigated. Consequently superconducting HGMS system can be applicable to remove iron oxide impurities from condenser water in thermal power plant.

• 상하수도학회지
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• 제19권3호
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• pp.330-337
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• 2005

This study was carried out to propose the managemental improvement of the purification plants and the distribution facilities which can minimize the formation of disinfection by-products in drinking water distribution system. The disinfection by-products were highly created in the water treatment plant that the organic matters were high and the chlorine dosage was excessive. The concentration of DSPs was shown the highest value in August and the lowest value in December, because of temperature and pre-chlorine dosage effect. From the result of tracer test, the travel time from the treatment plant to the end of pipeline was around 3-4 days in summer, 5-6 days in winter, respectively, and the DSPs concentration of the reservoir(end of pipe) was 2-3 times higher than that of the beginning point. The improvement of the chlorination process and structural reformation of distribution facility was demanded to minimize the DSPs increase from purification plant to the end of pipe.

• 상하수도학회지
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• 제28권2호
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• pp.249-255
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• 2014

So many drinking water treatment plants are under various difficulties by new reinforced effluent standards. Since the target turbidity, much higher than annual average, for designing sludge thickener have to be set to confront high turbidity season, the sludge at thickener should be put up for a long time during usual days. So the soluble manganese and chloroform may be formed under the anaerobic environment in the sludge thickener when the sludge retention time is longer with low turbidity. This phenomenon results in difficulties to keep regulatory level of the discharged effluent. For an effort to overcome the problems, a sludge aeration was successfully implemented into the thickening process. As a result, the final effluent quality and sludge volume were much improved; 41 % of manganese, 62 % of chloroform and 35 % of sludge volume. Additionally, effluent quality was improved ; 61 % of Manganese on aeration with pH control and we could make sure of stability effluent quality despite a long sludge retention time. We recommended the standard of installation sludge aeration equipment to nationally supply water treatment plant under effluent water quality problem ; Manganese, Chloroform, etc.

• 조명전기설비학회논문지
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• 제28권2호
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• pp.24-30
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• 2014

In this paper, a new remote terminal unit(hereafter RTU) is proposed to manage a wide range of applications and a variety of sensors (eg, pressure, water quality, temperature and humidity sensors, the amount of pollutants, $CO_2$, etc.) to monitor and control the facility such as water treatment plant, intake and effluent pumping station, water tank and distribution network. Fault status of local sensor devices and network are alerted by using the embedded fault handling capabilities of the RTU in the system and also sent to the fault handling server, by which fault can be easily monitored to users. The developed system was applied to one of K-water branch offices in Geoje city and improved its reliability and stability for controlling and monitoring water facility.