• 한국유기농업학회지
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• 제20권4호
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• pp.475-490
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• 2012

Since 1997, Korean Ministry of Knowledge Economy and Ministry of Environment have established data on some 400 basic raw and subsidiary materials and process like energy, petro-chemical, steel, cement, glass, paper, construction materials, transportation, recycling and disposal etc by initiating establishment of LCI database. Regarding agriculture, Rural Development Administration has conducted establishment of LCI database for major farm products like rice, barley, beans, cabbage and radish etc from 2009, and released that they would establish LCI database for 50 items until 2020 later on. The domestic LCI database for seeds, seedling, agrochemical, inorganic, fertilizer and organic fertilizer etc is only at initial stage of establishment, so overseas LCI databases are brought and being used. However, since the domestic and overseas natural environments differ, they fall behind in reliability. Therefore, this study has the purpose to select organic farming materials, survey the production process for various types of organic farming materials and establish LCI database for the effects of greenhouse gas emitted by each crop during the process. As for selecting methods, in this study organic farming materials were selected in the method of direct observation of material and bottom-up method a survey method with focus on the organic farming materials admitted into rice production. For the basic unit of carbon emission amount by the production of 1kg of organic farming material, the software PASS 4.1.1 developed by Korea Accreditation Board under Ministry of Knowledge Economy was used. The study had the goal to ultimately provide basic unit to calculate carbon emission amount in executing many institutions like goal management system and carbon performance display system etc in agricultural sector to be conducted later on. As a result, emission basic units per 1kg of production were calculated to be 0.04968kg-$CO_2$ for oystershells, 0.004692kg-$CO_2$ for expanded rice hull, and 1.029kg-$CO_2$ for bordeaux mixture liquid.

• Carbon letters
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• 제15권3호
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• pp.187-191
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• 2014

This study reports on the influence of N-butyl-N-methylpyrrolidinium tetrafluoroborate ($PYR_{14}BF_4$) ionic liquid additive on the conducting and interfacial properties of organic solvent based electrolytes against a carbon electrode. We used the mixture of ethylene carbonate/dimethoxyethane (1:1) as an organic solvent electrolyte and tetraethylammonium tetrafluoroborate ($TEABF_4$) as a common salt. Using the $PYR_{14}BF$ ionic liquid as additive produced higher ionic conductivity in the electrolyte and lower interface resistance between carbon and electrolyte, resulting in improved capacitance. The chemical and electrochemical stability of the electrolyte was measured by ionic conductivity meter and linear sweep voltammetry. The electrochemical analysis between electrolyte and carbon electrode was examined by cyclic voltammetry and electrochemical impedance spectroscopy.

• KSBB Journal
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• 제13권5호
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• pp.615-620
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• 1998

The readily fermentable carbon sources in swine were acetic acid, propionic acid and butyric acid at the average concentrations of 7.2 g/L, 2.2 g/L and 2.7 g/L, respectively. The swine waste also contained excess nitrogen and other mineral sources. In shake flask experiments, the optimal range of cell growth for Azotobacter vinelandii UWD were 1.0∼3.5 g/L of acetic acid, 0.7∼2.0 g/L of propionic acid and 0.5∼2.0 g/L of butyric acid. A mixture of these three acids simulating two times diluted swine waste supported the best cell growth but the amount of carbon sources was limited. In shake flask and fermentor experiments, an addition of 30 g/L of glucose increased the final cell dry weight 8 times while the final poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) concentration increased 86 times compared with using acid mixture only. A. vinelandii UWD preferred organic acids in the sequence of acetic acid, propionic acid, butyric acid, and valeric acid.

• Environmental Engineering Research
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• 제22권3호
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• pp.237-244
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• 2017

At present, in India, handling of solid waste has become a major challenge for the municipal authorities. Composting of solid waste, especially organic waste, can be one of the solutions to tackle the issue of handling solid waste. The present study is focused on agitated piles composting of flower waste (FW). Five combinations of FW with dry leaves (DL) and cow dung (CD) were prepared to conduct the study. Significant changes were observed due to the addition of bulking agent. The bulking material helps to reduce the production of leachate and also to maintain the aerobic condition within the piles. The reduction of total organic carbon was 21% in FW composting which increased by 36.48% during the composting of FW on addition of DL and CD. On the 120th day of composting, the pH of pile five (70 kg FW + 20 kg CD + 15 kg DL) was 7.33, electrical conductivity 2.77 mS/cm, total organic carbon 26.9%, total nitrogen 2.2%, and C:N ratio was 12. Appropriate proportion of waste mixture played an important role in providing favorable conditions for the microbial transformation of flower waste to stabilized compost. Finally, FW with the combination of CD and DL was found to be successful during pile composting.

• Composites Research
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• 제36권3호
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• pp.217-223
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• 2023

본 연구에서는 폴리아크릴로니트릴계 탄소나노섬유 스펀지의 제조 및 오일 흡착 거동을 조사하였다. 제조된 탄소나노섬유 스펀지는 물과 기름의 혼합용액에서 우수한 선택적 오일 흡착 능력을 보였으며, 탄소나노섬유 스펀지의 재사용시 흡착 능력도 확인하였다. 또한, 흡착제 내부구조에 정렬된 채널을 형성함으로써, 모세관 현상에 의하여 빠른 오일 흡착 거동을 보이는 탄소나노섬유 스펀지를 제조할 수 있었다. 이후 사용 폐기된 탄소나노섬유 스펀지는 질소 분위기에서 800℃로 열처리하여, 4-아미노페놀의 전기화학적 검출을 위한 센서로의 가능성을 검토하였다.

• 공업화학
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• 제10권6호
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• pp.822-827
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• 1999

본 연구에서는 에너지 밀도가 큰 초고용량 캐패시터를 제작하기 위한 기초 연구로서 활성탄소섬유의 물성과 유기 전해질의 특성이 초고용량 캐패시터의 전기화학적 특성에 미치는 영향을 조사하였다. 유기성 전해질의 경우는 이온의 크기가 수용성 전해질 보다 훨씬 크기 때문에 탄소전극의 세공크기에 많은 영향을 받으며, 용량을 발현할 수 있는 유효세공의 크기가 커야 한다는 것을 알 수 있었다. 혼합용매를 이용한 전해액의 조성은 큰 비축전용량과 빠른 충전속도, 그리고 낮은 ESR 및 방전전류의 세기에 대한 높은 비축전용량 유지성 등의 우수한 충방전 특성을 나타내는 것을 알 수 있었고, 전해질의 높은 이온전도도가 용량발현 및 자가방전 특성에 큰기여를 하고 있으며, 전해질 이온의 크기는 충전속도에 많은 영향을 미치는 것을 알 수 있었다.

• 한국물환경학회지
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• 제25권3호
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• pp.419-424
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• 2009

Characteristics of humic substances on the changes in dissolved organic matter (DOM) characteristics by biodegradation was investigated using three types of the artificial water samples composed of glucose and Suwannee River fulvic acid (SRFA). Some selected DOM characteristics including the specific UV absorbance (SUVA), the synchronous fluorescence spectra and the molecular weight (MW) were compared for the artificial water samples before and after 28-day microbial incubation. The changes of the DOM characteristics were minimal for SRFA during the incubation whereas they were significant for glucose. SUVA, dissolved organic carbon (DOC)-normalized fluorescence intensity, and MW values of glucose increased, suggesting that such labile organic compounds could be exclusively transformed into more humidified materials by biodegradation. For glucose-SRFA mixture, the selected DOM characteristics were greater than those estimated using the assumption that the individual changes of either glucose or SRFA are conservative for the mixture of the two materials. Our results suggest that the presence of humic substances (HS) may lead to the enhancement of the formation of refractory organic materials during biodegradation of labile compounds. Detailed analyses of size exclusion chromatography (SEC) revealed that the enhancement occurred for the DOM mixture with a MW range between 500 Da to 4000 Da.

• 한국지반환경공학회 논문집
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• 제25권5호
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• pp.5-13
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• 2024

본 논문에서는 유기오염물질인 benzyl butyl phthalate(BBP)에 오염된 퇴적토를 산/염기 개질활성탄을 이용한 퇴적토의 안정화 과정과 그 영향을 연구하였다. 실험을 통해 안정화제의 효율성을 평가하고, Lumbriculus variegatus를 이용한 생물학적 영향과 함께 개질활성탄의 혼합량 증가가 오염물질의 흡착에 미치는 영향을 분석하였다. 또한, low-density polyethylene를 사용한 공극수 내 유기오염물질 농도 측정을 통해 안정화제가 환경 내 오염물질의 이동을 어떻게 제한하는지에 대해 조사하였다. 연구 결과 Lumbriculus variegatus의 생존률이 90% 이상을 나타내었으며, 체내 BBP 축적 농도는 개질활성탄을 10% 혼합한 두 실험군보다 개질활성탄을 5% 혼합한 두 실험군이 약 2% 낮은 농도를 나타내었다. 수중으로의 용출량은 노출기간 7일 경과 후 모든 실험조건에서 대조군 대비 18% 이상 저감 되었으며, 노출기간 28일 후 모든 실험조건에서 25% 이상 저감된 효율을 확인하였다. 공극수의 농도를 측정하였다. 7일 노출 후의 결과는 기계혼합 실험군이 생물혼합 실험군 보다 높은 안정화율을 보였으며, 기계혼합 실험군에서, 개질활성탄을 10% 혼합한 실험군이 개질활성탄을 5% 혼합한 실험군 보다 1% 높은 안정화율을 보였다. 28일간 노출 후의 결과는 생물혼합 실험군이 기계혼합 실험군보다 높은 안정화율을 보였으며, 개질활성탄을 10% 혼합한 생물혼합 실험군이 개질활성탄을 5% 혼합한 실험군보다 약 0.1% 높은 안정화율을 보였다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
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• pp.42-45
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• 2006

A new and reusable energy source is water-treatment sludges. There is a significant need for understanding the characteristics of sludge combustion related to improving efficiency and ensuring the safety of this new energy source. Because sludges are composed of solids and gas mixture, the combustion of the mixture may become quite complex. Not only decomposition of conventional organic elements but also dust explosion may be important during the process of converting sludges into a new and safe form of energy. Sludge combustion mainly involves hydrogen, methane, hydro carbons, carbon, and organic particles. Dust explosion during the gasification stage may depend on the surrounding temperature and the composition of gases. The uncertainty in the explosive behavior of energetic source is noted in this work. We study the explosion characteristics of sludge combustion while the reusability of sewage sludges as a new form of energy is also investigated.

• 한국유기농업학회지
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• 제16권3호
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• pp.287-298
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• 2008

우분에 왕겨와 볏짚을 1:1, 1:2, 1:3의 부피비율로 혼합한 먹이조건이 지렁이의 생육, 분립생산량, 체조직으로의 유기물 전환율 및 전환효율을 조사하여, 적정 먹이조건을 추정하였다. 1. 우분+왕겨 혼합구가 우분+볏짚 혼합구보다 지렁이의 증체속도, 증식효율 및 분립생산량이 많았다. 특히 우분+왕겨 1:3 혼합비율이 지렁이 생육에 가장 알맞은 먹이조건이었다(Table 2). 2. 우분+왕겨 혼합 구에서 지렁이 체조직으로의 유기물 전환율과 전환효율이 높았던 것은 먹이 중의 휘발성 고형분과 전탄소함량이 높았기 때문이었다(Table 1, 4). 4. 지렁이 분변토는 약알칼리성이고, 전질소함량, 유효인산함량, CEC 및 치환 성 양이온 함량이 높아서 친환경 농자재로 유용하게 활용될 수 있다고 판단된다(Table 5).