• 한국환경과학회지
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• 제16권1호
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• pp.9-19
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• 2007

Comparing predicted PCDF isomer patterns with those obtained from a municipal waste incinerator assessed the role of two-phenol condensation pathways in the formation of PCDFs. Complete PCDF homologue and isomer distributions were obtained from a Fluidized Bed Incinerator (FBI). Two-phenol condensation model, dependent only on the distributions of phenols, was developed to predict the PCDF congeners produced from phenol precursors. R-squared values from linear correlations are presented for the dichlorinated through hexa-chlorinated isomer distributions between measured and predicted. They range from 0.00: to 0.1 far the di-chlorinated through hexa-chlorinated isomer sets. Agreement between predicted and measured PCDF isomer distributions was very poor for all homologues. Two-phenol condensation pathways are not likely to be the pre-dominant pathways in the formation of PCDF in a FBI. However, dibenzofuran (DF) is likely to be produced from a condensation of two phenols. This work demonstrates the use of PCDF homologue and isomer patterns for testing PCDF formation mechanism from two-phenol condensation pathways in municipal waste incinerators.

• 보일러설비
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• 통권67호
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• pp.114-115
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• 1999

• 한국고분자학회지:고분자과학과기술
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• 제9권6호
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• pp.473-478
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• 1998

• 유기물자원화
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• 제15권3호
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• pp.97-105
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• 2007

본 연구는 유기성 고형폐기물 처리에 적합한 벤치스케일 침출상 반응조를 이용하여 효율적인 산발효 및 수소발효의 거동특성을 살펴보았다. 산발효조는 혐기성 소화슬러지를 식종한 후 희석율 2.0, 3.0, $4.0d^{-1}$로 운전이 되었으며, 수소발효조는 열처리된 소화슬러지를 식종한 후 희석율 2.0, 4.0, $6.0d^{-1}$로 운전이 되었다. 산발효조는 희석율 $3.0d^{-1}$에서 운전되었을 때 최대의 COD 전환율 56.2%가 얻어졌으며 이때 전환된 COD는 모두 유기산으로 전환되었다. 반면에 수소발효조는 산발효조보다 높은 COD 전환율(49.3%)을 보여주지 못했지만, 높은 에너지 수율을 가지고 있을 뿐 아니라 친환경 청정에너지인 수소가스(전체 COD 중 5.1%)를 부산물로 얻을 수 있었다. 그러므로 처리목적에 따라 산발효나 수소발효를 유기성 고형폐기물에 적용할 수 있으며, 이는 혐기성처리 기술의 경제성을 향상시킬 수 있다.

• 한국환경과학회지
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• 제11권10호
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• pp.1089-1096
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• 2002

The objectives of this study were to investigate the desulfurization kinetics of paper sludge and limestone in a fluidized bed reactor according to bed temperature and air velocity. The experimental results were presented as follows ; First, the bed temperature had a great influence on the desulfurization efficiency of limestone and paper sludge. In paper sludge, the optimum condition in desulfurization temperature was at 80$0^{\circ}C$ and in limestone, that was at 850 $^{\circ}C$ or 900 $^{\circ}C$ Second, as air velocity increased, the desulfurization efficiency(or the absorbed amount of sulfur dioxide) by limestone and paper sludge decreased. And the absorbed amount of sulfur dioxide by paper sludge was larger than that of by limestone. Third, as the velocity increased and the optimum desulfurization temperature became, ks and the removal efficiency increased. So, ks, kd highly depended on the air velocity and bed temperature.

• 설비공학논문집
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• 제15권8호
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• pp.690-696
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• 2003

This paper presents the heat recovery performance of water fluidized-bed heat exchanger. Temperature and humidity ratio of waste gas are considered as important parameters in this study. Therefore, the heat recovery rate through water fluidized-bed heat exchanger for exhaust gases with various temperatures and humidity ratios can be estimated from the results of this study. Mass flow ratio (the ratio of mass flow rate of water to that of gas) and temperature of inlet water are also considered as important operating variables. Increase of heat recovery rate can be obtained through either high mass flow ratio or low temperature of inlet water with resultant low recovered temperature. The heat recovery performance with the mass flow ratio of about up to 10 has been investigated. The effect of number of stages of water fluidized-bed on the heat recovery performance has been also examined in this study.

• 한국태양에너지학회 논문집
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• 제22권1호
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• pp.9-21
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• 2002

To develope chemical heat pump using available energy sources, solar heat and other kinds of waste thermal energy, we have studied the heat transfer rate in cylindrical bed reactor packed with calcined Dolomite. Two dimensional (radial and circumferential) Partial differential equations, concerning heat and mass transfer in packed bed of calcined Dolomite, are solved numerically to describe the characteristics of the reaction of calcined Dolomite and heat transfer. The results obtained by numerical analysis about two dimensional profiles of temperature and conversion of reactant in the packed bed reactor and the amount of exothermic heat released from the reactor are follows. It was found that all of calcined Dolomite packed bed kept the reaction temperature of about 750K throughout the entire part of the bed, immediately after the steam was introduced exothermic reaction of hydration was proceeded from the packed bed inpu to output and from wall side to center. The rate of thermochemical reaction depends on the temperature and concentration and it is also governed by the boundary conditions and heat transfer rate in the particle packed bed.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.957-966
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• 1996

An attempt was made to measure the availability of waste heat, released from the cooling system of a small engine, which can be utilized for grain drying. An engine powered flat-bed rough rice dryer was constructed and the performance of the dryer with available engine-waste heat was analyzed for 10 , 20, 30 and 40 cm rough rice bulk depths with a constant dryer base area of 0.81$m^2$/min. The waste heat was sufficient to increase the drying air temperature 7 to 12$^{\circ}C$ at an air flow rate of 8.8 to 5.7㎥/min, while the average ambient temperature and relative humidity were 24$^{\circ}C$ and 70%. The minimum energy requirement was 3.26 MJ/kg of water removed in drying a 40 cm deep grain bed in 14h. A forty to fifty centimeter deep grained seems to be optimum in order to avoid over-drying in the top layers. On the basis of minimum energy requirement (3.26 MJ/kg ) , an estimation was made that the waste heat harvest from an engine of a power range of 1 to 10.5PS can dry about 0.1 to 1 metric on of rough rice from 23% to 15% m.c. (w.b) in 12 h at an average ambient temperature and relative humidity of $25^{\circ}C$ and 80%, respectively. The engine-waste heated grain dryer can be used in the rural areas of non industrialized countries where electricity is not available.

• Ocean Science Journal
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• 제40권2호
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• pp.91-100
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• 2005

Bioassay using the marine bacteria, Vibrio fischeri and rotifer, Brachionus plicatilis, and chemical analyses were conducted to assess the toxicity of the various sewage sludges, one of the major ocean dumped materials in the Yellow Sea of Korea. Sludge elutriates extracted by filtered seawater were used to estimate the ecotoxicity of the sludge. Chemical characterization included the analyses of organic contents, heavy metals, and persistent organic pollutants in sludge. Bacterial bioluminescent inhibition (15 min), rotifer mortality (24 hr) and rotifer population growth inhibition (48 hr) assay were conducted to estimate the sludge toxicity. EC50 15 min (inhibition concentration of bioluminescence after 15 minutes exposed) values by Microtox(R) bioassay clearly revealed different toxicity levels depending on the sludge sources. Highest toxicity for the bacteria was found with the sludge extract from dyeing waste and followed by industrial waste, livestock waste, and leather processing waste. Clear toxic effects on the bacteria were not found in the sludge extract from filtration bed sludge and rural sewage sludge. Consistent with Microtox(R) results, rotifer neonate mortality and population growth inhibition test also showed highest toxicity in dyeing waste and low in filtration bed and rural sewage sludge. High concentrations of persistent organic pollutants (POPs) and heavy metals were measured in the samples from the industrial wastes, leather processing plant waste sludge, and urban sewage sludge. However, there was no significant correlation between pollutant concentration levels and the toxicity values of the sludge. This suggests that the ecotoxicity in addition to the chemical analyses of various sludge samples must be estimated before release of potential harmful waste in the natural environment as part of an ecological risk assessment.

• 유기물자원화
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• 제8권3호
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• pp.112-117
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• 2000

음식물쓰레기는 높은 함수율과 VS(volatile solids) 함량으로 인해 수거, 운반 및 매립에 있어서 부패, 악취, 침출수 등의 주요 원인이 되고 있다. 음식물쓰레기의 산발효는 기질의 생분해도와 식종균의 분해능력과 같은 발효제한요소에 의해서 영향을 받는데, 음식물쓰레기의 생분해도는 잘 분해되지 않으며 전체 양의 약 50%를 차지하는 셀룰로우스 성분(야채류)과 깊은 연관이 있다. 이에 대한 효과적이면서도 경제적인 방법은 셀룰로우스의 분해능력이 뛰어난 미생물을 식종하는 것으로, 본 연구에서는 루멘미생물을 이용하여 산발효의 낮은 효율을 향상시키려 하였으며 그 값을 중온 산발효균과 비교하였다. Leaching bed 반응조에 루멘미생물을 식종했을 때의 산발효 효율은 희석율 $3.0d^{-1}$에서 71.2%의 최대값을 얻었으며, 한편 중온 산발효균을 식종하였을 때는 희석율 $4.5d^{-1}$에서 59.8%의 최대값을 얻었다. 이는 루멘미생물의 음식물쓰레기 분해능력이 보다 뛰어남을 보여주는 것이다.