• Journal of Dairy Science and Biotechnology
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• v.27 no.1
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• pp.13-18
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• 2009

We confirmed methane production and reduction of pollution during anaerobic digestion of milk waste and analyzed the economic potential of using milk waste as a renewable energy source. The milk waste sludge was obtained from the Pasteur milk factory and processed by anaerobic digestion to produce methane. The methane production from two completely mixed tank reactors with an effective capacity of 6 ${\ell}$, 15 days of hydraulic retention time (HRT), and a mid-temperature of $35^{\circ}C$ averaged 4.11 ${\ell}$/day. The total chemical oxygen demand (TCOD) during production decreased from an initial 31,416 mg/${\ell}$ to 13,500 mg/${\ell}$, showing a maximum TCOD removal efficiency of 60%. When HRT was reduced to 12 days, methane production increased by 44% under a high-temperature condition of $55^{\circ}C$. An economic analysis based on these results was applied to a Korean milk factory of typical size and demonstrated that the installation of an anaerobic digester could provide sufficient economic profit.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.87-100
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• 2003

This study was conducted in order to determine a proper level of molasses addition through the analysis of changes in appearance, nutritive and silage parameters before and after ensiling or deepstacking of broiler litter, to evaluate the effect of pelleting processed broiler litter and to develop methods to enhance palatability of broiler litter and reduce the adjustment period by ‘Hanwoo’ steers. Molasses addition was effective in ensiling and deepstacking of broiler litter and the proper addition level was about 5%. Changes in nutritive values of broiler litter by ensiling and deepstacking with or without molasses treatment were not great. Adding 5% molasses at deepstacking of broiler litter did not affect(P<0.05) in vitro digestion of dry matter and organic matter. Pelleting of broiler litter resulted in significant(P<0.05) moisture evaporation, organic matter reduction and nearly threefold increase of bulk density. Pelleting or molasses addition of broiler litter improved palatability by ‘Hanwoo’ steers and reduced the adjustment period by half(8-9 d).

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.185-192
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• 2011

BNR process is an effective method to remove high strength nitrogen included in wastewater and piggery wastewater. There have been many former studies about the induction of nitritation which have many advantages than full nitrification and the impacting factors on nitritation. Especially, it is reported that organic matter has a relation with nitritation. In this study, laboratory sacle reactor was operated using effluent of anaerobic digester, piggery wastewater and anaerobic digester effluent of piggery wastewater. After analyzing the operating results, the impact of organic matter on nitritation was analyzed by classified COD fractions. It was showed that nitritation is affected by organic matter especially by Ss. In conclusion, organic matter should be managed not just as a single gross parameter but in a classified form.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.3
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• pp.60-66
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• 2003

The purpose of this study was to investigate the effective pretreatment of foodwaste for the anaerobic digestion. Considering the foodwaste generation and the anaerobic digester for municipal wastewater sludges, the some pretreatment processes were performed such as the grinding of foodwastes with the addition of water, the mixing with sludges, and the hydrolysis with the addition of NaOH. The results were as followings ; 1. As the stage of feasibility test in laboratory scale, the foodwaste grinding using a household garbage disposer was performed with three different water mixing ratios of 1:1, 1:5 and 1:9 as weight base. The physicochemical characteristics of grinded foodwaste were analyzed and the effective conditions was recommended as the 1 :5mixing ratio of foodwaste and water and the below 8mm particle size. 2. And the mixing of foodwaste and municipal wastewater sludge was studied with three different mixing ratios of 1:9, 3:7 and 5:5 as weight base. The physicochemical characteristics of the mixed foodwaste and sludges were analyzed and the effective mixing ratio was recommended as 3:7 of foodwaste and sludge.

• Journal of Korean Society on Water Environment
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• v.20 no.4
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• pp.327-332
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• 2004

This study was carried out to examine the effect of gamma irradiation on the physico-chemical characteristics and ultimate anaerobic biodegradability of sewage sludge. The results found that the solubilization rates of SCOD in wasted activated sludge(WAS) and thickened sludge(T-S) with gamma irradiation of 3kGy were 8 times and 7 times greater than these of the raw WAS and T-S without the irradiation, respectively; each soluble concentration protein were 4 times and 3 times greater than these of the raw WAS and T-S; each soluble carbohydrate concentration was 8 times and 6 times greater than these of the raw WAS and T-S. The ultimate anaerobic biodegradabilities of WAS and T-S with gamma irradiation were 51 % and 50%, which corresponds to each 8% and 10% greater than these of the raw sludges. Approximately 83% and 81% of the each biodegradable substrates in the irradiated WAS and the T-S were degraded within 11 days with the first order decay rate coefficients, $k_1$ that ranged $0.143{\sim}0.164day^{-1}$ for WAS and $0.134{\sim}0.152day^{-1}$ for T-S. Based on the results, it can be concluded that when irradiated with gamma the solubilization of sewage sludge greatly increases resulting in substrates suitable for the subsequent biological treatment processes.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.6
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• pp.143-150
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• 2012

바이오에탄올 생산공정은 당 (Sugar)을 기반으로 하는 공정과 합성가스를 이용하는 공정으로 분류할 수 있다. 이 가운데 합성가스를 이용하는 공정은 촉매를 이용한 화학적 공정과 혐기성 발효에 의한 생물학적 공정의 두 가지로 나뉜다. Clostridium ljungdahlii는 일산화탄소와 수소가 주요 성분으로 구성되는 합성가스를 이용하여 에탄올과 아세트산을 생산할 수 있는 균주 중의 하나로 알려져 있다. 합성가스 발효공정에서 pH는 미생물의 증식과 에탄올 등의 생산에 아주 중요한 요인 중의 하나이다. 본 연구에서는 pH 조건이 미생물의 생장과 에탄올 생산성에 미치는 영향을 조사하였다. C. ljungdahlii 배양은 엄격한 혐기성 조건에서 100 ml의 serum bottle과 pH 제어가 가능한 반응기를 이용한 실험결과, 회분식 배양 조건에서는 미생물의 생장과 에탄올 생산을 위한 최적 초기 pH는 7.0로 나타났다. 미생물 농도는 0.57 g/L, 에탄올 농도 0.91 g/L로 나타났다. pH 4.5 이하에서는 미생물의 생장이 멈추는 것으로 나타났다. pH 제어가 가능한 생물반응기에서는 pH 6.0 일때 에탄올 생산량이 pH 7.0 일때 보다 높게 나타났다. 일정 수준의 미생물 농도를 유지한 조건에서 합성가스를 기포식으로 주입하고 pH 5.9에서 5.4까지 제어하였을 때 미생물량과 에탄올 농도가 증가하였다. 60 시간이 지난 후에 미생물의 농도는 0.498 g/L, 에탄올은 1.056 g/L까지 이르렀다.

• Journal of the Korean GEO-environmental Society
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• v.12 no.5
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• pp.37-42
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• 2011

The main objective of this study was to evaluate the current condition of harbor sediments and to estimate biochemical methane potentials from the harbor sediments. Sediment samples were collected from 10 different sampling sites. Ignition loss, elemental analyses, X-ray diffraction(XRD), X-ray fluorescence(XRF) tests were conducted to determine characteristics of the sediment. All sediments had similar elemental compositions and ignition loss were 8~10%. From the conventional BMP tests for 5 samples, cumulative methane production ranged from 11.9~15.5mL methane/(g of volatile solids), which were significantly lower than that for foods and paper. However, methane production rates for sediments were 5 to 20 times faster than those for foods and paper.

• Journal of Animal Science and Technology
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• v.50 no.6
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• pp.831-838
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• 2008

This study was conducted to evaluate effects of mixed microbes addition on physico-chemical, fermentative and microbial parameters of sawdust-based spent mushroom substrates(SMS). The SMS was inoculated with mixed microbes(Enterobacter ludwigii, Bacillus cereus, 2 strains of Bacillus subtillis, Saccharomyces cerevisiae and Lactobacillus plantarum) at 1% level(wet basis) and anaerobically fermented during the different periods(up to 8th week). Compared with the SMS before ensiling, the ensiled one had higher CP, NDF and ADF percentages and lower DM and NFC percentages. However, levels of change were very low. The in situ ruminal disappearance of SMS DM and NDF decreased with the ensiling period prolonged. For fermentative parameters, pH reduced and lactic acid contents increased after ensiling, compared with those after ensiling. At 8th week of ensiling, pH increased and lactic acid contents reduced again, compared with those at 4th week of ensiling; however, the silage still showed favorable fermentation status. Lactic acid bacteria counts did not change throughout 8 weeks of ensiling. Counts of total microbes and yeast reduced after 4th week of ensiling period. Counts of lactic acid bacteria and yeast at 8th week of ensiling were in the levels of 108cfu/g. These results indicate that anaerobic fermentation with microbial addition could be an effective way for the long term(8 weeks) storage of the SMS.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.10a
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• pp.60-61
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• 1996

염색폐수를 처리하기 위하여, 일반적으로 물리.화학적 공정과 호기성 생물학적 공정을 조합한 방법들을 사용하고 있다. 하지만 호기성 생물학적 공정은 난분해성 물질의 제거능력이 낮고, 염색폐수의 주된 오염원인 염료분자가 호기성 미생물에 대한 에너지원으로 적합하지 않아 분해되기 어려우며, 물리.화학적 공정을 이용한 처리방법으로도 높은 처리효율을 얻을 수가 없다. 이러한 문제점을 극복하기 위하여 염색폐수 처리에 혐기-호기공정을 이용하며, 혐기성 공정에서 생물학적으로 분해되기 어려운 고분자 물질들을 가수분해하여 생물학적으로 분해가능한 저분자물질로 전환시키고, 호기성 공정에서 저분자 물질을 효과적으로 처라할 수 있기때문에 기존의 염색폐수 처리공정에 비하여 훨씬 높은 처리효율을 얻을 수 있다. 특히, 혐기성 미생물은 호기성 미생물에 비하여 난분해성 물질에 대한 분해력이 높고, 생물독성 물질에 대한 내성이 강하기 때문에 수중생물에 유해한 염료를 함유한 염색폐수의 색도제거에 효과적인 것으로 기대된다. 또한, 막분리 공정은 유기물 및 미생물이 막표면에 축적, 증식함으로써 막세공에 막힘현상을 초래하여 역세척 등의 물리적인 방법이나 화학약품을 이용한 화학적 세척 방법으로도 투과플럭스의 회복이 불가능한 상태를 유발함으로 막의 수명을 단축시키는 원인이 된다. 따라서, 혐기-호기공정과 조합하면 색도성분 제거 및 막 오염의 원인이 되는 유기물 및 용존성 고형물을 제거하고, 막 오염의 억제를 통한 후 수염의 연장은 물론, 처리수의 수질향상에 활용될 수 있을 것으로 사료된다.1로 강구와 함께 공구강 vial에 장입 후, Spex mixer/mill을 이용하여 기계적 합금화 하였다. 기계적 합금화 공정으로 제조한 분말에 대한 X-선 회절분석과 시차 열분석으로 합금화 정도를 분석하였다. (Bi1-xSbx)2Te3 및 Bi2(Te1-ySey)3 합금분말을 10-5 torr의 진공중에서 300℃∼550℃의 온도로 30분간 가압소결하였다. 가압소결체의 파단면에서의 미세구조를 주사전자현미경으로 관찰하였으며, 상온에서 가압소결체의 열전특성을 측정하였다. (Bi1-xSbx)2Te3의 기계적 합금화에 요구되는 공정시간은 Sb2Te3 함량에 따라 증가하여 x=0.5 조성에서는 4 시간 45분, x=0.75 조성에서는 5 시간, x=1 조성에서는 6 시간 45분의 vibro 밀링이 요구되었다. n형 Bi2(Te1-ySey)3 합금분말의 제조에 요구되는 밀링시간 역시 Bi2Se3 함량 증가에 따라 증가하였으며 Bi2(Te0.95Se0.05)3 합금분말의 제조에는 2시간, Bi2(Te0.9Se0.1)3 및 Bi2(Te0.85Se0.15)3 합금분말의 형성에는 3시간의 bivro 밀링이 요구되었다. 기계적 합금화로 제조한 p형 (Bi0.2Sb0.8)2Te3 및 n형 Bi2(Te0.9Se0.1)3 가압 소결체는 각기 2.9x10-3/K 및 2.1x10-3/K 의 우수한 성능지수를 나타내었다.ering)가 필수적이다. 그러나 침전법에서 얻게 되는 분말은 매우 미세하여 colloid를 형성하게 되며, 이러한 colloid 상태의 미세한 침전입자가 filte

• Journal of Korean Society of Disaster and Security
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• v.12 no.1
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• pp.23-34
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• 2019

It is an urgent issue to manage and reduce non-point pollution sources for improving the water quality of stream and lakes in rural areas. In this study, in order to reduce non-point pollution sources in rural area, Gabion mattresses was proposed to provide protection of riverbanks with anaerobic and aerobic area. The utilization of this was assessed by lab scale model test and pilot plant test. After filling the inside of the gabion mattresses with aggregate, the filtration zone under anaerobic and aerobic conditions was formed to treat the contaminants. In addition, vegetation was deposited on the surfae of the gabion to prevent the inflow of soil and to promote purification by the plant. COD and nitrogen content (T-N, $NH_4{^+}$, -N, $NO_3{^-}N$) were monitored in model and field tests. The lab scale model test showed removal efficiency of 17% of TCOD, 35% of SCOD, 14% of TN, 62% of $NH_4{^+}$, -N, and 33% of $NO_3{^-}$ N. Also, pilot plant test showed removal efficiency of 24% of TCOD, 29% of SCOD, 47% of TN, 50% of $NH_4{^+}-N$, 33% of $NO_3{^-}$, N and 29% of TP.