• 한국축산시설환경학회지
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• 제16권1호
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• pp.51-60
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• 2010

본 연구는 시설재배에서 관비, 양액재배에 가축액비를 활용하기 위하여 한외여과막(UF) 분리 후 역삼투막 (RO)에서 농축액비를 제조하였다. 농축액비의 양분불균형을 조정하기 위하여 친환경농자재를 첨가하여 액비를 제조하였다. 처리구는 농축액비와 친환경농자재를 혼합하여 시용하는 조합처리를 두었으며 농축액비 단독처리구 (CS), 농축액비의 부족성분인 인산을 보충한 농축액비+골분혼합처리구 (CS+BM), 농축액비에 안산, 질소성분 보충을 위한 골분, 동물성아미노산 혼합처리구 (CS+BM+AA), 농축액바에 인산, 질소, 무기물 성분 보충을 위한 골분, 동물성아미노산, 해초분말 혼합처리구 (CS+BM+AA+SW)와 대조구로 원예연구소 상추 표준양액구 (NS) 등 5개 처리구를 두었다. 상추(Lactuca sativa L.)를 공시하여 수경재배에서 상추의 생육과 수량에 미치는 액비의 영향을 검토하였다. 1. UF/RO 공정을 통하여 SS (Suspended solid)의 수치가 20 이하로 양액 재배시 막힘 문제가 없는 액비의 생산이 가능하였다. UF/RO에서 생산된 농축액의 비료가치는 식물생육에 필요한 질소, 칼리, 황 등 다량의 다량원소와 다양한 미량원소를 함유하고 있어서 비료로서 가치가 있었으나 칼리함량이 상대적으로 높고 질소, 인산 함량이 낮아 농축액비 (CS) 단독처리구는 양분의 불균형을 초래하여 생육이 불량하여 상추수량이 화학양액대비 51%의 저조한 수량을 나타내었다. 2. 농축액비에 골분, 동물성아미노산, 해초분말을 혼합한 시용구는 대조구인 표준양액과 대비 84% 상추수량을 나타내었다. 따라서 농축액비에 골분, 동물성아미노산, 해초분말을 첨가한 혼합용액을 조제하면 화학양액에 비하여 수량감소가 16% 있었으나 유기물에서 유래한 액비로 상추 수경재배에 활용이 가능 할 것으로 판단된다.

• 신재생에너지
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• 제4권2호
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• pp.21-30
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• 2008

Anaerobic digestion (AD) is the most promising method of treating and recycling of different organic wastes, such as OFMSW, household wastes, animal manure, agro-industrial wastes, industrial organic wastes and sewage sludge. During AD, i.e. degradation in the absence of oxygen, organic material is decomposed by anaerobes forming degestates such as an excellent fertilizer and biogas, a mixture of carbon dioxide and methane. AD has been one of the leading technologies that can make a large contribution to producing renewable energy and to reducing $CO_2$ and other GHG emission, it is becoming a key method for both waste treatment and recovery of a renewable fuel and other valuable co-products. A classification of the basic AD technologies for the production of biogas can be made according to the dry matter of biowaste and digestion temperature, which divide the AD process in wet and dry, mesophilic and thermophilic. The biogas produced from AD plant can be utilized as an alternative energy source, for lighting and cooking in case of small-scale, for CHP and vehicle fuel or fuel in industrials in case of large-scale. This paper provides an overview of the status of biogas production and utilization technologies.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.202-205
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• 2008

Anaerobic digestion(AD) is the most promising method of treating and recycling of different organic wastes, such as OFMSW, household wastes, animal manure, agro-industrial wastes, industrial organic wastes and sewage sludge. During AD, i.e. degradation in the absence of oxygen, organic material is decomposed by anaerobes forming degestates such as an excellent fertilizer and biogas, a mixture of carbon dioxide and methane. AD has been one of the leading technologies that can make a large contribution to producing renewable energy and to reducing $CO_2$ and other GHG emission, it is becoming a key method for both waste treatment and recovery of a renewable fuel and other valuable co-products. A classification of the basic AD technologies for the production of biogas can be made according to the dry matter of biowaste and digestion temperature, which divide the AD process in wet and dry, mesophilic and thermophilic. The biogas produced from AD plant can be utilized as an alternative energy source, for lighting and cooking in case of small-scale, for CHP and vehicle fuel or fuel in industrials in case of large-scale. This paper provides an overview of the status of biogas production and utilization technologies.

• 한국미생물·생명공학회지
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• 제34권4호
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• pp.363-367
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• 2006

Food wastes were decomposed into the Mugri (Isung Engineering, Korea), a food waste reduction machine, with adding sawdust of cryptomeria. Degradation effects were better when the machine worked at over 45$^{\circ}C$ than those at the lower temperature. Thermophilic bacteria were isolated from cryptomeria sawdust and the food waste products degraded by the machine. The isolates from cryptomeria sawdust were classified into 3 genera (Acinetobacter baumannii, Enterobacter sp. and Erwinia cypripedii) and almost all the isolates from the degraded products were partially identified as Bacillus sp. by 16S rDNA sequence analysis. The isolated thermophilic bacteria showed degradative enzyme activities. In the case of addition of the 30 thermophilic bacteria into the machine, degradation rate of food wastes was almost twice as high with increasing process temperature up to 6$^{\circ}C$.

• Advances in concrete construction
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• 제6권1호
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• pp.47-68
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• 2018

This article reports the utilization of fly ash (FA) waste product from industry and silpozz which is an agro-waste from agriculture as an environmental friendly material in construction industry. The evaluation of strength and durability study was observed using FA and silpozz as a partial replacement of Ordinary Portland Cement (OPC). The studied parameters are compressive strength, flexural strength, split tensile strength and bond strength as well as the durability study involves the acid soluble chloride (ASC), water soluble chloride (WSC), water absorption and sorptivity. Scanning electron microscopy (SEM) and XRD of selected samples are also done. It reveals from the test results that the deterioration factor (DF) in compressive strength is 4% at 365 days. The DF of split tensile strength and flexural strength is 0.96% and 0.6% at 90 days respectively. The minimum slip is 1mm and 1.1mm after 28 days of testing bond strength for NWC and SWC sample respectively. The percentage decrease in bond strength is 10.35% for 28 days SWC samples. The pre-cast blended concrete samples performed better to chloride diffusion. Modulus of elasticity of SWC samples are also studied.The water absorption and sorptivity tests are conducted after 28 days of curing.

• Advances in concrete construction
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• 제6권4호
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• pp.387-405
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• 2018

Geopolymer concrete is a fastest developing field of research for utilizing industrial and agro waste materials as an alternative for Portland cement based concrete. Geopolymers are formed by the alkaline activation of aluminosilicates rich materials termed as geopolymerization. The process of geopolymerization requires elevated temperature curing which restricts its application to precast industry. This review summarizes the work carried out on developing the geopolymer concrete with the addition of various mineral admixtures at ambient curing temperature conditions. An overview of studies promoting the geopolymer concrete in general building construction is presented. Literature study revealed that geopolymer concrete with the addition of admixtures can exhibit desirable properties at ambient temperature conditions.

• Journal of the Korean Wood Science and Technology
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• 제34권5호
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• pp.52-58
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• 2006

Coffee chaff for manufacturing of the 6 mm thick cement-bonded boards was obtained from a coffee processing industry at Omuo-Ekiti, in Ekiti State, Nigeria. Boards were produced with three levels of cement to coffee chaff ratio of 1.5:1, 2.5:1 and 3.5:1; and at three levels of mixing curing reagent of 2.0%, 2.5% and 3.0%. Three dimensional properties of thickness swelling (TS), water absorption (WA) and linear expansion (LE) were investigated after 48 hours immersion in water. The mean values obtained for TS, WA and LE ranged from 0.46% to 1.47%, from 11.52% to 24.00%, from 0.19% to 0.35%, respectively. The most dimensionally stable boards were produced at the highest mixing levels of curing reagent and cement to coffee chaff ratio of 3.0% and 3.5:1, respectively. The coffee chaff is suitable as raw material for the manufacture of cement-bonded composites and it would be able to stimulate and activate the use of other agro-byproducts for the manufacture of value-added panels.

• Advances in Energy Research
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• 제3권3호
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• pp.181-194
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• 2015

In this work, an experimental study of the gasification on wood was carried out in downdraft type fixed bed Gasifier attached with 10 kW duel fuel diesel engine. The main objective of the study was to use wood as the biomass fuel for downdraft Gasifier and to evaluate the operating parameter of gasifier unit to predict its performance in terms of gas yield and cold gas efficiency. The influence of different biomass on fuel consumption rate, gas yield and cold gas efficiency was studied. Composition of producer gas was also detected for measuring the lower heating value of producer gas to select the feed stock so that optimum performance in the existing gasifier unit can be achieved. Under the experimental conditions, Lower heating value, of producer gas, cold gas efficiency and gas yields, using wood as a feed stock, are $4.85MJ/m^3$, 46.57% and $0.519m^3/kg$.

• 한국미생물·생명공학회지
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• 제45권4호
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• pp.330-342
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• 2017

Statistical design of experiments was employed to optimize the media composition for the production of laccase from Bacillus sp. PK4. In order to find the key ingredients for the best yield of enzyme production from the selected eleven variables viz yeast extract, glucose, zinc sulphate, copper sulphate, potassium chloride, magnesium sulphate, calcium chloride, ferrous sulphate, sodium chloride, potassium dihydrogen phosphate ($KH_2PO_4$) and dipotassium hydrogen phosphate ($K_2HPO_4$), Plackett-Burman design was applied. The $MgSO_4$, $FeSO_4$, and $CuSO_4$ showed positive estimate, and their concentration optimized further. The steepest ascent method and Box-Behnken method revealed that 1.5 mM $MgSO_4$, 0.33 g/l $FeSO_4$ and 1.41 mM $CuSO_4$ were optimal for the laccase production by Bacillus sp. PK4. This optimization strategy leads to enhancement of laccase production from 2.13 U/ml to 40.79 U/ml. Agro-wastes residues replace the carbon source glucose in the optimized media namely sugarcane bagasse, wheat bran, rice husk, and groundnut shell, among these groundnut shells (117 U/ml) was found to enhance the laccase production significantly. The laccase produced by Bacillus sp. PK4 was found to have the potential to degrade persistent organic pollutant benzo[a]pyrene.

• Journal of Microbiology and Biotechnology
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• 제21권9호
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• pp.947-953
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• 2011

A fungal strain, Aspergillus terreus strain GA2, isolated from an agricultural field cultivating sweet sorghum, produced feruloyl esterase using maize bran. In order to obtain maximum yields of feruloyl esterase, the solid state fermentation (SSF) conditions for enzyme production were standardized. Effective feruloyl esterase production was observed with maize bran as substrate followed by wheat bran, coconut husk, and rice husk among the tested agro-waste crop residues. Optimum particle size of 0.71-0.3 mm and moisture content of 80% favored enzyme production. Moreover, optimum feruloyl esterase production was observed at pH 6.0 and a temperature of $30^{\circ}C$. Supplementation of potato starch (0.6%) as the carbon source and casein (1%) as the nitrogen source favored enzyme production. Furthermore, the culture produced the enzyme after 7 days of incubation when the C:N ratio was 5. Optimization of the SSF conditions revealed that maximum enzyme activity (1,162 U/gds) was observed after 7 days in a production medium of 80% moisture content and pH 6.0 containing 16 g maize bran [25% (w/v)] of particle size of 0.71-0.3 mm, 0.6% potato starch, 3.0% casein, and 64 ml of formulated basal salt solution. Overall, the enzyme production was enhanced by 3.2-fold as compared with un-optimized conditions.