• Journal of Ecology and Environment
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• 제44권1호
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• pp.45-53
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• 2020

Background: The black soldier fly (Hermetia illucens) is gaining attention as an efficient decomposer of food waste. However, recalcitrant compounds such as plastics mixed into food waste may have negative effects on its growth and survival. Moreover, its efficiency of food waste degradation may also be affected by plastics. In addition, salt (NaCl) can also be present in high concentrations, which also reduces the efficiency of H. illucens-mediated food waste treatment. In this study, we assessed the growth of black soldier fly larvae (BSFL) reared on food waste containing polyethylene (PE) and polystyrene (PS) and NaCl. The weight of BSFL was measured every 2-4 days. Survival and substrate reduction rates and pupation ratio were determined at the end of the experiment. Results: The total larval weight of Hermetia illucens reared on food waste containing PS was greater than that of the control on days 20 and 24. However, the survival rate was lower in the group treated with 5% PS, as was substrate reduction in all PS-treated groups. The weight of BSFL reared on food waste containing PE was lower than that of the control on day 6. PE in food waste did not affect the survival rate, but the pupation ratio increased and substrate consumption decreased with increasing PE concentrations. Regardless of the plastic type, the addition of NaCl resulted in decreased larval weight and pupation ratio. Conclusions: Larval growth of black soldier fly was inhibited not by plastics but by substrate salinity. Additional safety assessments of larvae reared on food waste containing impurities are needed to enable wider application of BSFL in vermicomposting.

• Tribology and Lubricants
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• 제40권2호
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• pp.61-66
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• 2024

Micro-plastics are synthetic high-differentiation chemicals of less than 5mm in size, and are deposited not only on the sea surface but also on the coast. If these micro-plastics are not properly separated from the sand, they can threaten marine ecosystems. Thus, in the present study, we aimed to apply cyclone separator to the micro-plastic retrieval in order to predict the movement of particles according to the formation of the cyclone separator by applying the centrifugal force of the particle in accordance with the rotational movement of the air. The cyclone separator has three shapes, the first one is a typical interconnected cyclone separator. The second is the horn form, except for the cylinder in a regular cyclone separator, and the third is a form that increases the horn's height twice in the second. The numerical analysis simulation of the Cyclone separator used the Fluent software package. The output speed of the Cyclone separator was 5 to 13m/s at 1m/s intervals. The simulated particles include sand, Styrofoam, PET, PP, and PU. Sand particles are assigned a fixed diameter of 2mm, while other particles have a diameter of 3mm. As a result of the analysis, the first form was not separated from plastic. The Styrofoam separation efficiency in the second showed its highest efficiency at 72.7% at 7m/s, and the efficiency decreased after 12m/s as the sand particles were mixed into the plastic attachment location. In the third form, the separation efficiency of Styrofoam at 12m/s was highest at 67.9%.

• 신재생에너지
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• 제2권2호
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• pp.118-125
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• 2006

The target of this work was the process development of demonstration plant to produce the high quality alternative fuel oil by the pyrolysis of mixed plastic waste. In the first step of research, the bench-scale units of 70 t/y and the pilot plant of 360 t/y had been developed. Main research contents in this step were the process performance test of pilot plant of 360 ton/year and the development of demonstration plant of 3,000 t/y, which was constructed at Korea R & D Company in Kimjae City. The process performance of pilot plant of 360 t/y showed about 80% yield of liquid product, which was obtained by both light gas oil(LGO) and heavy gas oil(HGO), The boiling point range distribution of LO product that was mainly consisting of olefin components in PONA group appeared at between that of commercial gasoline and kerosene. On the other hand, HO product was mainly paraffin and olefin components and also appeared at upper temperature distribution range than commercial diesel. Gas product showed a high fraction of $C_3\;and\;C_4$ product like LPG composition, but also a high fraction of $CO_2$ and CO by probably a little leak of process.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.523-526
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• 2006

The target of this work was the process development of demonstration plant to produce the high quailty alternative fuel oil by the pyrolysis of mixed plastic waste. In the first step of research, the bench-scale units of 70t/y and the pi lot plant of 360 t/v had been developed. Main research contents in this step were the process performance test of pilot plant ot 360ton/year and the development of demonstration plant of 3 000 t/y which was constructed at Korea R & D Company in Kimjae City. The process performance of pilot plant of 360 t/v showed components in PONA group appeared at between that of commercial gasoline and kerosene. On the other hand, HO product was mainly paraffin and olefin components and also appeared at upper temperature distribution range than commercial diesel. Gas product showed a high fraction of $C_3\;and\;C_4$ product like LPG composition, but also a high fraction of $CO_2$ and CO by probably a little leak of process.

• International Journal of Fluid Machinery and Systems
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• 제9권3호
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• pp.256-264
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• 2016

To meet the demand of higher handling capacity, a mixed-flow submersible deep well pump was designed and tested. The main hydraulic components are made of plastics, which is free of erosion, light-weight, and environment-friendly. To simplify plastic molding process, and to improve productivity, an axial-radial guide vane was proposed. To clarify its effect on the performance, a radial guide vane and a space guide vane are developed as well. By comparison, the efficiency of the pump equipped with the axial-radial guide vane is higher than the radial guide vane and is lower than the space guide vane, and its high efficiency range is wide. The static pressure recovery of the axial guide vane is a bit lower than the space guide vane, but it is much larger than the radial guide vane. Taking the cost and molding complexity into consideration, the axial-radial guide vane is much economic, promoting its popularity for the moderate and high specific speed submersible deep well pumps.

• 자원리싸이클링
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• 제23권5호
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• pp.44-54
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• 2014

인천광역시에서 배출되는 종량제봉투 안에는 재활용 가능자원이 4.5% (알루미늄캔류 0.2%, 철캔류 2.5%, 유리류 1.8%), 에너지회수가 가능한 자원이 92.5% (종이류 23.0%, 플라스틱류 15.5%, 가연성 기타류 54.0%) 및 매립이 필요한 불연성 기타류가 3.0%로 분석되었다. 알루미늄캔류, 철캔류 및 유리류는 기존의 매립처리보다 재활용처리가 효과적이며, 종이류와 플라스틱류는 기존의 단순 소각처리보다 폐기물 고형원료 (SRF)로 만들어 에너지회수처리하는 편이 더 효과적이고, 가연성 기타류는 기존의 단순 소각처리가 재활용처리보다 효과적이다. 본 연구에서 제안한 폐자원별 처리방안을 적용하면 2,068,948 Million Btu의 에너지가 절감되고, 21,008 $MTCO_2E$의 온실가스가 저감되는 것으로 분석되었다. 총 에너지 절감량을 경제적 효과로 환산하면 연간 약 422억 원의 비용절감 효과가 있으며, 총 온실가스 저감량을 승용차의 이산화탄소 배출량으로 환산하면 연간 약 4,119대의 운행감축 효과가 있는 것으로 나타났다. 종량제봉투 내 가연성 물질의 저위발열량은 종이류 1,936 kcal/kg, 플라스틱류 5,079 kcal/kg, 가연성 기타류 2,462 kcal/kg로 분석되었다. 종이류와 플라스틱류를 적절하게 혼합한다면 SRF로 활용이 가능하고, 가연성 기타류는 저위발열량이 고형연료 기준을 충족시키지 못하고 구성성분들이 폐기물 고형연료로 사용하기엔 부적절하였다.

• 청정기술
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• 제23권2호
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• pp.133-139
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• 2017

식물로부터 유래하는 바이오매스를 25% 이상 함유하는 바이오 베이스 플라스틱은 탄소배출을 억제하는 효과가 있고, 한정된 자원인 석유의 소비량을 줄일 수 있으며, 산화생분해 첨가제를 추가 적용하면 폐기 후에는 미생물에 의해 생분해되기 때문에 친환경적인 소재로 최근 연구가 활발하다. 본 연구에서는 염화비닐수지에 식물체 유래 가소제, 생분해 촉매제를 첨가하여 생분해성 및 물성변화등을 관찰하였다. 또한 초기 신장율과 인장강도 등의 물성이 우수한 자연에서 분해되는 산화 생분해 투명 바이오 필름을 제조하여 식품포장재로서의 제품 안전성을 시험하였다. 염화비닐 수지와 1차 가소제, 2차 가소제, 방담제, 안정제를 비율에 맞게 투입한 다음, 고속혼합기에서 혼합한 후, 압출성형기를 이용하여 압출한 뒤 냉각 와인더 롤을 통해 두께 $12{\mu}m$의 대조구와 산화생분해 투명 바이오 필름을 제조하였다. 기계적 물성으로 인장강도, 연신율 및 최대하중연신율을 측정하였으며, 생분해 실험을 실시하였다. 식물체 유래 가소제, 생분해 촉매제로 제조된 투명 바이오 필름은 대조구 대비 인장강도 및 연신율이 큰 차이가 없는 것으로 나타났다. 또한 ASTM D 6954-04 방법에 따라 45일간 생분해 테스트를 한 결과 표준물질인 셀룰로오스 분말 대비 61.4%의 생분해를 나타내었다.

• 자원리싸이클링
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• 제10권2호
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• pp.34-40
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• 2001

유제품 공병(high impact polystyrene, HIPS)은 통상 수집 , 파쇄, 알루미늄 제거를 위한 화학처리, 수세를 겸하여 함께 들어 있는 PP, PE, 가소화 PVC등과의 분리과정을 경유하여 파쇄품으로 만들어지고 있다. 다시 압출기를 이용하여 이들 파쇄품을 칩으로 제조한 후 화력발전소의 부산물인 석탄회(fly ash)를 filler로 사용하여 조성별로 혼합하여 사출형 시편 제조기를 사용하여 시편을 제조하여 이들 석탄회를 포함한 시료들에 대한 열적 성질과 기계적 특성을 조사하고 인장강도, 모듈러스 및 신율을 비교하였다. 또한 Izod 충격강도와 굴곡강도를 함께 조사하였다. 이들 혼합된 석탄회가 수지의 기계적 특성에 미치는 영향을 조사하여 이들로부터 재활용을 위한 복합물의 조성으로 5∼30%가 가장 적합하였다.

• 한국재료학회지
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• 제30권1호
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• pp.22-30
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• 2020

Small fishing vessels are manufactured using FRP. Various studies have been conducted to increase the strength of the composite material by mixing alumina powder with resin. Tensile tests and flexural strength tests are conducted to examine the effect of alumina powder on the strength of GFRP. In the current study, resin/alumina composites at different alumina contents (i.e., 0, 1, 5, and 10 vol%) have been prepared. The physical and mechanical properties of the prepared composites have been investigated. From the results, the tensile strength of the specimen with alumina powder mixed in at 10% shows the highest value of 155.66 MPa. The tensile strength of the specimen mixed with alumina powder increases with the amount of alumina powder impregnated. In the flexural strength test, the flexural strength of neat resin without alumina powder has a highest value of 257.7 MPa. The flexural modulus of ALMix-5 has a highest value of 12.06 GPa. Barcol hardness of ALMix-10 has a highest value of 51. We show that alumina powder leads to decreasing cracks on the surface and decreasing length area of delamination.

• 대한임상독성학회지
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• 제4권1호
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• pp.55-57
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• 2006

Cyanides and Hydrogen cyanide are used in production of chemicals, electroplating, photographic development, making plastics, fumigating ships, and some mining processes. We experienced of Hydrogen cyanide inhalation injury. A 45-year-old man worked at electroplating. As soon as he mixed sodium cyanide with acid, cyanide produced hydrogen cyanide, occasionally he inhaled Hydrogen cyanide and he lost his consciousness. He was moved to near hospital and took emergency treatment and then was transferred to our hospital. On arrival he had severe dyspnea, metabolic acidosis, and tachycardia. After he was treated with supportive method he recovered his consciousness in 20 hours at emergency room.