• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.1
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• pp.84-89
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• 2003

The purpose of this study was to evaluate and improve the pre-treatment facility for foodwaste and sewage sludge mixture treatment. The process of foodwaste pre-treatment consists of storage, classification with crushing, and thickening. The effluent of sewage treatment facility was used as the diluting and washing water. The panicle size of foodwaste after pre-treatment was almost under 2mm, the mixture of foodwastes and sewage sludge showed an advantage to the anaerobic digestion. The amount of gas production increased from 0.8ton/day ($CH_4$ : 0.5ton/day) to 3.5ton/day ($CH_4$ : 2.3ton/day) after the anaerobic digestion of the foodwastes and sewage sludge mixture. The amount of sludge cake increased from 11.2ton/day to 21.2ton/day. Therefore, the proper operation of the foodwaste pre-treatment facility was contributed to the efficient anaerobic digestion of foodwaste and sewage sludge mixture treatment.

• Journal of the Korean Institute of Gas
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• v.16 no.2
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• pp.52-59
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• 2012

The sprinkler system is regarded as the most effective fire extinguishing system. In this study, we proposed a sprinkler layout optimization framework based on fire simulation and mathematical programming. As a case study, the target space in the form of ordinary residence was set up with the size of $5.2m(L){\times}5.4m(W){\times}2.4m(H)$, and we constructed the fire scenario that polyurethane couch was ignited through carelessness. And we simulated and analyzed fire speed, temperature change and heat release rate according to the type and number of sprinklers installed. Through the formulation of installation and damage costs depending on sprinklers, the sprinkler layout showing optimal performance was resulted from mathematical programming.

• Resources Recycling
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• v.26 no.1
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• pp.59-68
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• 2017

This study has been conducted to evaluate the effects of a single stage anaerobic co-biogasification of food waste and primary sewage sludge mixture (1 : 5 V/V%) according to mixing ratio (0% : CAP0, 0.5% : CAP0.5, 1%: CAP1.0) in red pepper powder, which was reported as the material anti-bacterial and anti-fungi, under mesophilic condition ($35^{\circ}C$). during 31 days. It showed that red pepper powder effected anaerobic bacteria, Especially, Hydrolytic bacteria and methanogenic bacteria was inhibited much more than Acetogenic bacteria with red pepper powder. at CAP0, Experimental cumulative methane yield (ECMY) and Experimental bio-energy production (EBEP) were 0.17 L $CH_4/g$ $VS_{fed}$ and 1,465 cal/g $VS_{fed}$ individually as the highest value during 31 days.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.2 no.3
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• pp.23-32
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• 1982

This study was conducted to evaluate the temperature effects on the nightsoil, anaerobic digestion, whether it could be operated with a higher organic loading rate at a higher temperature during summer months, or with a lower organic loading rate at a lower temperature during winter months. A laboratory completely mixed digester was continuously operated at 11 different temperatures from $18.5^{\circ}$ to $60^{\circ}C$ with 30 days of HRT. The study results indicated that the best efficiency occurred at a temperature range of $35^{\circ}$ to $40^{\circ}C$, at which BOD and VS removal efficiencies were respectively 71 and 53 percent, and gas production rate was $0.6m^3/kg$ VS fed or $16m^3/m^3$ fed. BOD removal efficiency would be increased to 78 percent if the digester effluent settled for 24 hours. Since the digester efficiency decreased beyond this temperature range, this suggested the digester need not to operate a higher temperature even during the summer months. The laboratory results were in good agreement with those of the existing digester operated at a temperature range of $32^{\circ}$ to $40^{\circ}C$. Application of septage or cow manure to the digester with nights oil at a rate of 1 to 1 did not greatly affect the digester performances. In addition, the digester effluent could be treated aerobically without any dillution water. BOD and SS removal efficiencies were greater than 90 percent in this case.

• Korean Journal of Poultry Science
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• v.34 no.4
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• pp.287-294
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• 2007

Current study was conducted to identify the effects of dietary supplementation of Aspergillus oryzae ferments (AOF) cultured under normal (NAOF) or nitrogen-deficient (NMAOF) environment on feed efficiency, nutrient digestibility for broiler chicks. Fecal microbes and ammonia gas production were also determined. A total of 168 male Avian chicks, 2-wk-old, were randomly assigned into 56 cages, three chicks per cage. There were seven treatments (Control, NAOF 0.05, 0.1, 0.5%, NMAOF 0.05, 0.1, 0.5%), with 8 replicates (cages) per treatment. There was no significant difference in nutrient digestibility between two AOF groups, but the digestibility was greatly(p<0.05) improved by AOF supplementation. Total microbial account significantly (p<0.05) differed between the treatment groups with the highest number for NNAOF, followed by NAOF and control. In the case of Escherichia coli and Salmonella, the AOF supplementation significantly (p<0.05) reduced their numbers in feces, with a particular reduction in NNAOF group. Levels of ammonia gas generation were in order of control>NAOP>NNAOP. The current data implied that AOF supplementation, particularly grown under nitrogen-deficient environment, would be a feasible way to improve feed efficiency for broiler production, as well as to reduce environmental cost. However, further studies remain for industrial application.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.146.1-146.1
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• 2011

석탄가스화복합발전(IGCC)공정에서 가스화기를 거쳐 생성된 합성가스로부터 $CO_2$를 효과적으로 분리/회수하기 위해 가스 고형화법을 제안하였다. 가스 하이드레이트 형성과정에서의 반응특성을 살펴보기 위하여 반응시간에 따른 가스소모량과 기상의 $CO_2$ 조성 변화를 측정하였다. 순수계와 촉진제 첨가계 (TBAB (10, 40 wt%), TBAF (10, 34 wt%), THF (4, 19 wt%))에 대하여 하이드레이트 생성 후의 기상과 하이드레이트상의 $CO_2$ 조성을 측정하였으며, 그 결과 하이드레이트 형성법에 의해 고농도의 $CO_2$가 하이드레이트상에 포집되는 것을 확인하였다. 가스 소모량 측정실험에서는 THF 19.1 wt%를 첨가하였을 때 가장 큰 소모량을 보였으며, TBAF 10 wt%를 첨가하였을 때 가장 적은 가스소모량을 보였다. $CO_2$ 조성 변화 실험에서는 가스 소모량 실험과 마찬가지로 THF 19.1 wt%를 첨가하였을 때 가장 큰 조성변화를 보였다. 이는 THF의 첨가로 인하여 가스 하이드레이트로의 전환율 증가로 많은 양의 $CO_2$ 기체가 하이드레이트 상에 포집되었음을 나타낸다. 속도론적인 측면에서는 모든 실험조건에서 하이드레이트 형성반응이 1시간 이내에 대부분 종결되는 것을 볼 수 있었다. 또한 $^1H$-NMR을 통하여 혼합가스 하이드레이트의 구조적인 분석을 진행하였다. 본 실험에서 얻어진 결과는 가스 하이드레이트 형성법을 이용한 합성가스 분리 공정 개발에 중요한 기초자료가 될 것으로 사료된다.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.529-536
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• 2003

A total of 72 finishing pigs(L${\times}$Y${\times}$D; 80kg of initial body weight) were employed for 5 weeks to investigate the effects of feeding mushroom substrate waste(MSW) treated with pleurotus ostreatus and probiotics on productivity, carcass traits, nutrient digestibility and emissions of harmful gases and malodor in manure. Treatments were Control(C: basal diet), T1(3% MSW) and T2(3% MSW+ 0.1% probiotics). Average daily gain(ADG) was lower(p<0.05) in pigs fed a T1 diet than those fed a C diet, however, there was no difference in ADG of pigs fed diets between C and T2. Similar trends were found in feed/gain(F/G) among treatments, though feed intake was not different. No differences were found in back fat thickness among treatments, but carcass dressing percentage was significantly(p<0.05) improved in pigs fed a T2 diet compared to C or T1 diets. Nutrient digestibilities including dry matter, crude protein, energy and crude fiber were lower(p<0.05) in T1 than C or T2. $NH_3$ and $H_2S$ gas emissions were reduced(p<0.05) or not produced in pig manure from T2 as compared to C or T1. In conclusion, the present result shows that feeding MSW with probiotics is desirable for finishing pigs in terms of productivity, carcass traits and nutrient digestibility. It also appears that the emission of harmful gases and malodor in manure can be reduced by the inclusion of probiotics in the diet.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.264-270
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• 2010

Waste activated sludge from sewage treatment plants mainly consisted of flocs of bacterial cell, and thus hard to be stabilized anaerobically due to rigid cell walls. One of the pretreatment methods to overcome this barrier is the venturi cavitation system (VCS) adopting hydrodynamic cavitation. This research was conducted to investigate the effects of the pretreatment of waste activated sludge by VCS on the anaerobic digestibility. Depending on the pretreatment period with the VCS, methane production, COD removal and VS removal efficiency increased 41%~45%, 36.5%~43.1% and 18.4~24.1%, respectively, compared to the control case. The increase in methane production from digester was 3.3~4.2 times higher than the theoretical methane potential of the increased SCOD after the VCS pre-treatment. This suggests that the VCS pre-treatment not only increases SCOD but also improves the digestibility of solid fractions. The energy mass balance indicated that the energy consumed for sludge pre-treatment could be recovered by the increased methane production after pre-treatment, suggesting the high potential for field application.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.638-644
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• 2017

Pitch based activated carbon fibers for electric double layer capacitor (EDLC) electrodes were treated by oxyfluorination via varying the ratio of fluorine and oxygen gases to improve high power property. As the partial pressure of fluorine increased, the oxyfluorinated activated carbon fibers showed an increase of linear fluorine functional groups. While the oxygen functional groups increased, no changes was observed with respect to the partial gas pressure. The specific surface area and pore volume decreased due to the etching reaction on the activated carbon fiber surface through oxyfluorination, but the mesopore volume increased about 4.5 times. In the case of activated carbon fibers treated with 50% of the fluorine gas partial pressure, the specific capacitance increased to about 29% and 61% at scan rates of 5 and 50 mV/s, respectively. The improvement of the specific capacitance was believed to be due to the introduction of oxygen and fluorine functional groups on the activated carbon fiber surface and the increase of mesopores through oxyfluorination.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.251-251
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• 2011

해양 투기가 금지되면서 혐기소화를 통해 최종적으로 발생되는 폐기물 양을 줄이고 메탄 등의 바이오 가스를 얻어 이를 에너지로 얻기 위한 많은 공정들이 현장에 적용되고 있다. 하지만 혐기 소화 과정을 마친 후 유출되는 유출액은 고농도의 유기물질 및 암모니아성 질소, 인산염 등을 다량으로 함유하고 있어 적은 양이라도 하천이나 호수 등에 유입되면 수질 악화와 부영양화를 초래할 위험성이 크다. 이번 연구에서는 음식물류 폐기물로부터 바이오가스를 생산하기 위한 혐기소화 공정에서 발생하는 유출액의 방류수 수질기준 확보와 경제성을 만족시킬 수 있는 처리공정의 상용화 기술을 개발하기 위해 생물학적 처리， 물리 화학적 처리를 통합한 공정을 적용하였다. P건설사 혐기소화 유출액 pilot plant(1 ton/day) 운전 결과 50~70% 로 $NO_2$-N 이 약 1,000 mg/$\ell$정도로 축적되는 현상을 보였으며 상대적으로 $COD_{Cr}$의 농도는 400~600 mg/$\ell$로 C/N 비가 낮아 탈질이 어려울 것으로 판단하였다. 이에 실험실 규모에서의 실험을 진행하였다. $NO_2$-N와 $NO_3$-N을 기준으로 McCarty 양론비 기준 80% 에서 300%까지 메탄올을 주입해 제조 폐수와 실제폐수로 실험을 진행하였고 제조폐수로 실행된 실험에서 아질산 탈질의 효율을 확인하였다. 미생물이 메탄올에 순응 후 완전 탈질에 걸리는 시간은 약 2.5 일로 확인 되었으며 메탄올이 추가로 주입되지 않은 반응조의 $NO_2$-N의 탈질량은 메탄올이 이론값 100% 주입 된 반응조에 비해 30% 이하의 처리 효율을 나타냈다. 이론값을 기준으로 메탄올이 100% 주입된 반응조는 약 96.1%의 탈질 효율을 보였으며 메탄올 순응 후에 약 1.5 일의 HRT가 단축되었기 때문에 메탄올에 장시간 순응 시 탈질 효율이 더 좋아질 것으로 보인다. 아질산탈질에 대한 실험실 규모 연구결과를 토대로 pilot plant에서 재현성 검토를 목적으로 운전을 수행하였다. 무산소조의 HRT는 2.7 일 이었으며 호기조의 HRT는 4.1 일 이었다. 유입수의 평균 $COD_{Cr}$ 농도는 2,878 mg/L, T - N 농도는 2,723 mg/L로 나타났으며 $NO_2$-N 기준 C/N비 1.2-1.8의 메탄올을 주입하였을 때 96% 이상의 탈질율을 보였다.