• 한국환경과학회지
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• 제10권2호
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• pp.153-158
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• 2001

The biosorption abilities of different parts of waste brown seaweeds and their derivatives to remove heavy metals (Cd, Zn, Pb, Cu, Fe, Ni, Mn) from waste were evaluated. The two parts of waste brown seaweeds (Undaria pinnatifida) were stems and sporophyls, and the brown seaweed derivatives were alginic fibers, active carbon added alginate(AC-alginate) and dealginate. The abilities of the sporophyls to adsorb the heavy metal ions were higher than those of stems, and those of alginates were slightly higher than those of dealginate in single ion solution. With decreasing the size of biosorbents, the velocity and the amount of adsorption increased. The abilities of alginate to remove the heavy metal ions increased in multi-ion solutions by adding active carbon to alginate. The selectivity of these biosorbents(alginate, AC-alginate) to lead ion was highest and to manganese ion was lowest.

• 농업과학연구
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• 제41권4호
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• pp.369-377
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• 2014

This study was carried out to evaluate the effect of rice husk (RHB) and food waste biochar (FWB) on upland soil with sandy loam texture, in terms of physico-chemical analysis, lettuce seed germination test, and orgainc carbon leaching experiment. RHB and FWB had different physico-chemical properties each other. Carbon to nitrogen ratio (C/N ratio) of RHB was 32, showing two times higher than that of FWB. FWB had high salt and heavy metal content, compared to RHB. This is probably due to different ingredients and production processing between two biochars each other. Results of germination test with Lettuce showed lower germination rate when FWB was applied because of higher salt concentration compared to control and RHB. Organic carbon leaching test using saturated soil column (${\Phi}75{\times}h75mm$) with $10MT\;ha^{-1}$ biochar application rate, showed higher saturated hydraulic conductivity in rice husk biochar treatment column, compared to control and food waste biochar treatment. The highest total organic carbon concentration in column effluent was lower than those in both of rice husk biochar and food waste biochar, whereas the differences was negligible after 9 pore volumes of effluent. Consequently, biochars from byproducts such as rice husk and food waste in sandy loam textured upland soil could enhance a buffer function such as reduction of leaching from soil, but the harmful ingredient to crops such as high salt and heavy metals could limit the agricultural use of biochars.

• 한국건설순환자원학회논문집
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• 제11권4호
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• pp.391-399
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• 2023

최근 증가하는 폐플라스틱의 재활용 방법으로 저온 열분해 기술이 연구되고 있다. 폐플라스틱 저온 열분해 기술은 에너지 자원으로 활용할 수 있는 열분해유를 생산하지만, 고체의 잔류물이 발생한다. 폐플라스틱 열분해 잔류물은 활용 범위가 낮아 대부분 매립 처리하고 있다. 본 연구에서는 혼합 폐플라스틱 열분해 잔류물를 활성탄으로 재활용하기 위한 연구를 수행하였다. 혼합 폐플라스틱 열분해 잔류물의 화학적 활성화를 통해 활성탄을 제조하고, 그 특성에 대해 조사하였다. 공업분석을 통해 잔류물의 고정탄소량이 33.69 %인 것으로 확인하였다. 활성탄 제조에는 화학적 활성화를 활용하였으며. 활성화제로 KOH를 사용하였다. KOH와 잔류물의 혼합비율의 영향을 조사하기 위해 0.5, 1.0, 2.0의 비율로 시료를 혼합하였다. 혼합한 시료는 활성화 온도는 800 ℃에서 1시간 동안 화학적 활성화를 진행하였다. BET를 통한 활성탄 특성 분석 결과 KOH의 혼합비율이 증가할수록 비표면적이 증가하는 것을 확인하였다.

• Environmental Engineering Research
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• 제24권1호
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• pp.117-126
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• 2019

Activated carbon is carbon produced from carbonaceous source materials, such as coconut shells, coals, and woods. In this study, an activated carbon production system was analyzed by carbonization and activation in terms of environmental impact and human health. The feedstock of wood wastes for the system reduced fossil fuel consumption and disposal costs. Life cycle assessment methodology was used to analyze the environmental impacts of the system, and the functional unit was one tonne of wood wastes. The boundary expansion method was applied to analyze the wood waste recycling process for activated carbon production. An environmental credit was quantified by avoided impact analysis. Specifically, greenhouse gases discharged from 1 kg of activated carbon production system by feeding wood wastes were evaluated. We found that this system reduced global warming potential of approximately $9.69E+00kg\;CO_2-eq$. compared to the process using coals. The environmental benefits for activated carbon production from wood wastes were analyzed in contrast to other disposal methods. The results showed that the activated carbon system using one tonne of wood wastes has an environmental benefit of $163kg\;CO_2-eq$. for reducing global warming potential in comparison with the same amount of wood wastes disposal by landfilling.

• Carbon letters
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• 제11권2호
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• pp.131-136
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• 2010

Propellant waste was impregnated on the surface of activated carbon fiber and heat-treated at different temperature to introduce newly developed functional groups on the ACF surface. Functional groups of nitrogen and oxygen such as pyridine, pyridone, pyrrol, lacton and carboxyl were newly introduced on the surface of modified activated carbon fiber. The porosity, specific surface area, and morphology of those modified ACFs were changed as increasing the heat-treated temperature from 200 to $500^{\circ}C$. The optimum heat-treatment temperature was suggested to $500^{\circ}C$, because lower temperature given rise to the decrease of specific surface area and higher temperature resulted in the decrease of weight loss. Propellant waste can be used as an useful surface modifier to porous carbons.

• Korean Chemical Engineering Research
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• 제50권2호
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• pp.310-316
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• 2012

활성탄소 분말과 탄소필터를 이용하여 실리콘 폐슬러리에서 회수한 폴리에틸렌글리콜(polyethylene glycol, PEG) 폐액의 색도 개선연구를 수행하였다. 활성탄소의 사용량, 흡착온도 및 흡착시간 변화에 따른 색도 변화를 관찰하였다. 탄소필터를 사용할 경우 충진된 활성탄소의 재생에 따른 성능 저하 여부를 검정하였다. 활성탄소의 표면적은 색도 개선에 큰 영향을 주지 않았다. 흡착제 함량에 따른 색도 변화 결과로부터 흡착제의 최적 사용량은 100~150 mg-C/g-PEG이였다. 흡착제 양을 고정하고 흡착 온도를 상온에서 $100^{\circ}C$까지 변화시키면서 PEG의 APHA(American Public Health Association) 색 값을 관찰한 결과 폐 PEG의 색도 개선을 위해서는 $40{\sim}50^{\circ}C$ 온도에서 운전하는 것이 가장 효과적이었다. 활성탄소필터의 운전 조건별 APHA 특성을 관찰하였고 APHA=53인 폐 PEG를 $APHA{\leq}10$로 정제 가능함을 확인하였다. 흡착에 사용된 활성탄소필터는 증류수를 순환시켜 세척함으로써 큰 성능 저하 없이 효과적으로 재생됨을 확인하였다.

• Korean Chemical Engineering Research
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• 제55권2호
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• pp.220-224
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• 2017

본 논문에서는 전기절연판이나 접착제로 널리 사용되는 페놀수지를 초임계 유체를 이용하여 카본입자로 재활용 하는방법을 연구 하였다. 폐페놀수지는 불융/불용 특성으로 대부분 매립하거나 소각처리하고 있으며, 환경오염 방지차원에서 페놀수지의 새로운 재활용 기술 개발이 매우 필요한 실정이다. 폐페놀수지를 재활용하기 위해 다양한 아/초임계 용매(에탄올, 아세톤, 물, 메탄올)를 선정하여 처리하였다. 그 결과 기존의 카본입자의 제조 방법들 보다 훨씬 낮은 온도 조건($350{\sim}380^{\circ}C$)에서 카본입자를 제조할 수 있었다. 본 연구에서는 재활용된 카본입자의 FT-IR, XRD, TGA, SEM, EDS 분석을 통하여 반응용매에 따른 카본입자의 특성을 고찰하였으며, 모든 용매에 대해 동일한 화학구조 및 비정질 구조를 가지는 카본입자를 제조 할 수 있었다.

• 한국지반환경공학회 논문집
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• 제12권1호
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• pp.35-40
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• 2011

제철소에서 용강을 제조할 때에 사용되는 전로(Converter)나 레이들(Ladle) 등의 노체용 내장 내화물로 마그네시아-카본벽돌이 많이 사용되고 있다. 그러나 이렇게 사용되고 있는 마그네시아-카본 벽돌의 경우 교체 이후 전량폐기되고 있다. 이렇게 폐기되는 폐 마그네시아-카본 벽돌을 분쇄하여 활성화재를 이용한 연약지반 및 오염지반의 고화재로 사용함으로써 연약지반 및 오염지반의 고형화를 통하여 연약지반의 강성증가와 함께 오염지반에서 발생하는 중금속 및 기타 유해물질의 용출에 대한 안정화에 영향을 미칠 것으로 판단된다. 본 논문에서는 폐 마그네시아-카본을 이용한 연약지반의 강도 증가에 대한 내용에 대하여 나타내었다.

• 한국분말재료학회지
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• 제12권2호
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• pp.112-116
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• 2005

In the present study, the focus is on the analysis of carbothermal reduction of oxide powder prepared from waste WC/Co hardmetal by solid carbon under a stream of argon for the recycling of the WC/Co hard-metal. The oxide powder was prepared by the combination of the oxidation and crushing processes using the waste $WC-8 wt.\%Co$ hardmetal as the raw material. This oxide powder was mixed with carbon black, and then this mixture was carbothermally reduced under a flowing argon atmosphere. The changes in the phase structure and gases discharge of the mixture during carbothermal reduction was analysed using XRD and gas analyzer. The oxide powder prepared from waste $WC-8wt.\%Co$ hardmetal has a mixture of $WO_{3} and CoWO_{4}$. This oxide powder reduced at about $850^{\circ}C$, formed tungsten carbides at about $950^{\circ}C$, and then fully transformed to a mixed state of tungsten carbide (WC) and cobalt at about $1100^{\circ}C$ by solid carbon under a stream of argon. The WC/Co composite powder synthesized at $1000^{\circ}C$ for 6 hours from oxide powder of waste $WC-8wt.\%Co$ hardmetal has an average particle size of $0.3 {\mu}m$.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.47-48
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• 2023

In the domestic industrial sector, greenhouse gases emitted from the cement industry account for about 10%, with most of them generated during the cement clinker calcination process. During the calcination process, 57% of carbon dioxide is emitted from the decarbonation reaction of limestone, 30% from fuel consumption, and 13% from electricity usage. In response to these issues, the cement industry is making efforts to reduce carbon dioxide emissions by developing technologies for raw material substitution and conversion, improving process efficiency by utilizing low-carbon alternative heat sources, developing CO₂ capture and utilization technologies, and recycling waste materials. In addition, due to the limitations in purchasing and storing industrial byproducts generated from industrial facilities, many studies are underway regarding the recycling of construction waste. Therefore, this study analyzes the manufacture of calcium silicate cement (CSC), which can store carbon dioxide as carbonate minerals in industrial facilities, and aims to contribute to the development of environmentally friendly regenerated cement using construction waste.