• Journal of environmental and Sanitary engineering
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• v.13 no.1
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• pp.32-43
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• 1998

혐기성대상과정중 메탄생성균(methanogenic bacteria)에 의한 메탄생성시 주요 기질인 아세트산 (acetic acid)을 분해할 경우에 여러 가지 복합기질 중 아미노산 첨가에 의한 분해속도증가에 미치는 영향과 투입한 아미노산이 미생물에 의하여 생체량으로 합성되는 정도를 고찰하였다. 실험결과 메탄생성균은 glycine, serine, threonine, aspartic acid, trytophan 등의 혐기성미생물의 생체량합성에 필요한 물질을 투입할 경우에 아세트산의 분해속도가 증가하였으며, 여러 가지 아미노산을 혼합하여 주입한 결과 분해속도가 17% 향상되었다. 한편, 메탄생성균의 lysing에 의하여 생성된 유기물은 메탄이나 이산화탄소의 최종산물로 전환되기보다는 새로운 메탄생성균의 생체량을 형성하는데 직접 이용되었으며, 아세트산의 분해속도를 52% 증가시켰다. 단순기질(sole substrate)과 복합기질(complex substrate)의 분해는 미생물의 생체량합성에 필요한 여러 가지 중간대사산물간의 상호자극효과에 의하여 복합기질이 용이한 것으로 나타났으며, 유입기질내 활성이 강한 슬러지의 농도는 혐기성처리에 매우 중요한 부분을 차지하였다.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.4
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• pp.363-368
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• 2010

The overall indicator of microbial activity in the fermentation-extinction reaction of food waste by using bio wood-chips were investigated by considering adenosine tri-phosphate(ATP). Degradation rate of organic compounds, which was represented by chemical oxygen demand(COD) and total nitrogen(TN), was increased with the concentration of adenosine tri-phosphate during fermentation-extinction reaction of food waste by using bio-wood chips. With this view, the ATP would be one of the overall evaluation indicator of organic degradation in the species of bio-wood chip for the fermentation-extinction of food waste.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.2
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• pp.65-73
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• 2018

This study was carried out for 20 days in a bio-drying batch reactor under the blowing conditions of 0.75, 1.00, 1.25, and $1.50L/min{\cdot}kg$ in order to optimize the operating conditions for the bio-drying of food wastes. The decomposition rate of organic matter during the bio-drying operation period was analyzed using modified Gompertz model. The maximum organic degradation (P) was 2.31, 2.52, 2.27 and 1.88 kg at air flow rates of 0.75, 1.00, 1.25 and $1.50L/min{\cdot}kg$, and the maximum organic degradation rate was 0.33, 0.45, 0.28, and 0.18 kg/day at 1.00, 1.25 and $1.50L/min{\cdot}kg$, respectively, showing excellent organic decomposition efficiency at a air flow rate of $1.00L/min{\cdot}kg$. The lag growth phase time (${\lambda}$) of the bio-drying reactor was 2.10, 1.48, 1.15, and 1.06 days at 0.75, 1.00, 1.25 and $1.50L/min{\cdot}kg$, respectively. The water removal rate in the operation of bio-drying reactor of food waste increased with the increase of air flow rate from the early stage of bio-drying to the middle stage, and the highest water removal rate was observed at the air flow rate of $1.00L/min{\cdot}kg$ at the end of bio-drying. The optimum air flow rate condition of bio-drying reactor was $1.00L/min{\cdot}kg$.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.47-55
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• 2005

Seasonal variations of remineralization and inorganic nitrogen removal capacity were measured from Dec. 2001 to Apr. 2004 in a tidal flat located in south-western pan of Gwanghwa island, Korea by measuring the sediment oxygen demand (SOD) and denitrification. SOD was higher in muddy sediment (Dong-Mak; three year average=$683;m^{-2}d^{-1}$) than sandy sediment(Yeocha; three year average=$457;m^{-2}d^{-1}$). The SOD was high in summer and tended to be lower in winter. During the sediment incubation in Apr. 2002, production of oxygen from sediment was observed implying active benthic photosynthesis. Denitrification was also higher in muddy sediment (Dong-Mak: $5.4;m^{-2}d^{-1}$) than sandy sediment (Yeocha; $3.4;m^{-2}d^{-1}$). The denitrification rate corresponds to the carbon remineralization rate of 9.3 and $5.9\;mg-C\;m^{-2}d^{-1}$ in Dong-Mak and Yeocha, respectively. The denitrification rates were lower compared to rates observed in other coastal area $(0{\sim}200\;{\mu}mole\;m^{-2}h^{-1})$. Although Kwanghwa tidal flat sediments are replete in organic matter, remineralization activity seems to be limited by the availability of labile organic matter. The Kwangwha tidal flat may have potential to effectively remove large load of organic matter. Net remineralization rates were 196 and $132\;mg-C\;m^{-2}d^{-1}$ in Dong-Mak and Yeocha, respectively.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.57-60
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• 2001

미생물 활성도와 그에 따른 유기물의 분해율은 미생물의 호흡률과 직접적인 관계가 있다. 본 연구는 매립종료후 경과기간이 1년인 Y 매립지와 10년인 C 매립지의 오염특성을 조사하였고, 오염토양 미생물의 산소소비속도를 이용하여 매립종료기간에 따른 오염토양의 산소소비율을 비교 평가 하고자 하였다. C 매립지의 오염토양에 대한 SCO $D_{cr}$ TOC는 Y 매립지에 비해 낮은 함량으로 나타났으나 T-N, N $H_3$-N의 함량은 큰 차이를 보이지 않았다. TOC/T-N비로 보았을 때 Y 매립지에 비해 C 매립지가 낮은 것으로 나타나 연령이 많은 경우 분해성 유기물의 함량은 적은 것으로 판단된다. 산소소비율 실험결과 Y 매립지가 산소소비율이 높은 것으로 나타났으며, C 매립지도 대조토양에 비해 높은 산소소비율을 보였다. 따라서 매립종료 후 경과기간이 10년인 매립지의 미생물의 산소소비율을 보았을 때 여전히 생물학적 안정화가 종료되지 않은 것을 알 수 있었다.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.1
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• pp.21-30
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• 1998

The effects of compost inoculation on the degradation of cellulosic fraction in composting of food waste and paper mixture were investigated by bench-scale composting. With the increase of seed inoculation, the time to reach the peaks of temperature, $CO_2$ evolution rate, and ammonia evolution rate was reduced, indicating that seed compost had beneficial effects on the enhanced degradation of organic materials at the early stage of composting. However, the final conversion of organic matters and the loss of ammonia were not affected by the amount of seed compost inoculated. The increasing of seed inoculum also resulted in the higher level of cellulase activity at initial stages and rapid rise to the maximums, suggesting that initial supply of sufficient cellulolytic microorganisms might facilitate the evolution of cellulase activity. The cellulose was degraded substantially during the increasing phase of cellulase activity, while they showed similar values at the end of 20 days composting. As a result, the seed inoculation seemed to be effective to the enhanced evolution of cellulase activity and cellulose degradation at initial stage of composting. But it did not contribute to increase the final degradation of cellulose after the entire composting reaction of 20 days.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1993.05a
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• pp.33-41
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• 1993

The objectives of this experiment performed were to determine the potential using of solar radiation to destroy organic contaminants in water by photolysis and to develop the process and improve its performance. We used lab, scale of recirculation photoreactor with 30, 50, 80ppm initial concentration of TCE and Ti $O_2$ anatase, respectively. Adsorption constant, reaction constant were obtained and compared using the Langmuir-Hinshelwood kinetics equation. Ti $O_2$ anatase demonstrated the highest conversion ratio co TCE among Ti $O_2$ anatase, ZnO and F $e_2$ $O_3$ in this experiment. It was shown that in case of two component system, TCE+ phenol, as the concentration of phenol increased in the feed solution, TCE decomposition rate decreased.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.05a
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• pp.127-128
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• 2001

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.1
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• pp.23-33
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• 2017

In this study, water and organic treatment efficiency and operating characteristics (temperature, salinity effect) were evaluated when food waste with high water content was treated by Bio-dying method. In addition, the optimum conditions for producing pellets for evaluating the decomposition products as SRF(Solid Refuse Fuel) after Bio-drying and evaluating the use value of SRF as a solid fuel were analyzed. As a result, the temperature, $CO_2$ concentration, organic matter removal rate and weight reduction rate according to the daily dose were about 86% and 68% at the input of 2.4 kg/day. The optimal food waste input was estimated to be 2.4 kg/day. As a result of the pellet molding and produce, Pellets can be produced within 10~25% of raw material water content. It was judged that the water content of 25%, which showed the best quality results in terms of external shape maintenance and strength. The high calorific value of SRF of decomposition products after Bio-drying was more than 3,500 kcal/kg.

• Journal of Animal Science and Technology
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• v.48 no.5
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• pp.699-708
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• 2006

Ground rice, barley and corn were fed separately to the ruminally cannulated Hanwoo (Korean native cattle) for comparing their in situ and in vitro degradabilities, microbial growth, pH and gas production. It has been found that nearly all the dry matter (DM) and organic matter (OM) in barley and rice disappeared during 24 hr suspension in the rumen, but those in corn were only reduced by around 67%. Water soluble DM and OM fractions(‘a’), ranked from highest to lowest was corn, then rice and finally barley, but the order was reversed for content ‘b’, degradable fraction during time ‘t’. Judging by the degradation parameter of ‘b’ fraction, degradation rates per hour of DM and OM for barley were 38.3% and 37.2% respectively, significantly higher than those for rice (7.7% and 5.6%) and corn (4.1% and 1.3%). In general, results obtained from in vitro degradability of DM and OM were lower than those from in situ trials, but the ranking order of degradability was in agreement between both trials. In particular, ground rice has relatively lower in vitro microbial growth than corn or barley, but exhibited higher gas production. In addition, in vitro microbial growth of ground rice increased with up to 12 hr of incubation period, thereafter experienced a decrease with extended incubation time. pH of in vitro solution of rice decreased following 9 hr of incubation but gas production increased rapidly during the same period. From the results of DM and OM degradabilities and pH changes of in vitro solution with incubation time, it is concluded that rice represents a good source of energy for stability of rumen fermentation.