• 한국환경농학회지
• /
• 제24권1호
• /
• pp.24-28
• /
• 2005

본 연구에서는 시설하우스 폐양액이 고추의 생육과 양분 흡수에 미치는 영향을 평가하고 폐양액 관주시 부가적으로 얻을 수 있는 관개 효과를 산출함으로써 폐양액의 토양 시비에 따른 농업적 가치를 평가하였다. 시설하우스 폐양액의 토양 관주시 Ca, Mg K 등 염류의 증가로 인하여 pH와 EC는 상승하였고, 총질소는 암모늄태 질소와 질산태 질소의 증가와 함께 처리 후 100 mg $kg^{-1}$ 이상 증가하였다. 고추 생육은 화학비료 70% 및 폐양액 30% 혼합처리구와 화학비료 50% 및 폐양액 50% 혼합처리구에서 양호하였으며 양분 흡수도 동일한 경향을 나타내었다. 고추 수확량은 화학비료 70% 및 폐양액 30% 혼합처리구에서 가장 높은 것으로 조사되었다. 1일 발생되는 폐양액(288 L 10 $a^{-1}\;day^{-1}$)을 토양에 시용하여 증발산되는 수분을 보충할 경우 최고 $409.86m^2$의 면적을 관개할 수 있는 것으로 산출되었다. 이상의 결과를 통해 폐양액의 토양처리는 화학비료 대체 효과와 폐양액의 정화 효과를 동시에 얻을 수 있으며 적정량 시용시 주변 환경에 미치는 영향을 최소화하면서 지속적인 처리가 가능할 것으로 판단되었다.

• 한국건설순환자원학회논문집
• /
• 제6권2호
• /
• pp.119-127
• /
• 2011

본 연구의 목적은 폐도자기 분말도 변화에 따른 순환골재 강도 증진에 관한 연구로 유동성은 폐도자기 분말 치환율이 증가할수록 유동성이 감소하는 경향으로 나타났으며, 공기량은 KS 한도범위를 만족하는 것으로 나타났다. 압축강도는 순환골재 및 폐도자기 분말 치환율이 증가할수록 증가경향이고, 내구성으로 건조수축에 의한 길이변화는 폐도자기 미분말이 커질수록 다소 완만한 건조수축율을 나타내었고, 또한 단열온도상승은 순환골재 대체율 및 폐도자기 미분말이 증가할수록 최고온도에서 약 $6{\sim}10^{\circ}C$정도 낮게 나타내어 수화열에 의한 균열저감 효과를 발휘하였다. 순환골재 사용량을 30%정도 권장 하고 있지만 점토인 폐도자기의 분말도를 조절하여 사용할 경우 순환골재의 다량 사용시에는 콘크리트의 제반성상에 문제가 없을 것으로 판단되었다.

• 자원리싸이클링
• /
• 제18권4호
• /
• pp.14-23
• /
• 2009

각종 전기전자제품의 제조과정 또는 사용 후 해체 과정에서 배출되는 폐전기전자기기(WEEE) 스크랩으로부터 금, 은, 팔라듐등 귀금속과 구리, 주석, 니켈등 유가금속의 회수는 금속 재활용측면뿐만 아니라 환경 유해물질 저감의 측면에서도 매우 중요하다. 일반적으로 WEEE 스크랩은 여러 종류의 금속과 합금뿐만 아니라 내화 산화물과 플라스틱 성분 등으로 구성된 복합물질이다. WEEE 스크랩에 함유된 귀금속과 유가금속은 가스휘발공정, 건식공정 또는 습식공정으로 회수될 수 있다. 그러나 가스휘발공정과 습식공정은 아직 기초연구단계에 머물고 있는 실정으로, 현재 WEEE 스크랩으로부터 금, 은, 팔라듐 및 구리 등을 회수하기위한 상업적인 플랜트의 대부분은 건식공정으로 이루어지고 있다. 따라서 본 논문에서는 WEEE 스크랩으로부터 귀금속 및 유가금속을 회수하는 건식공정에 대하여 소개하고, 폐동슬래그를 슬래그 형성제로 활용하여 WEEE 스크랩으로부터 귀금속 및 유가금속을 회수하기 위한 규모 확대 실험에 대한 결과를 제시한다.

• 청정기술
• /
• 제21권3호
• /
• pp.141-152
• /
• 2015

환경문제가 대두되면서 이미 선진국의 바이오 플라스틱 공급업체들은 소비자의 관심과 재활용 규제가 친환경 포장재 등의 수요를 불러일으킬 것으로 전망하였다. 이러한 수요에 대응하기 위해 옥수수와 같은 식물체를 활용해 만든 여러 형태의 바이오 플라스틱을 출시해 왔으며, 국내 업체들에서도 점차 이에 대한 관심을 높여가고 있다. 점차 강화되고 있는 폐기물 부담금과 불안정한 국제 유가를 고려할 때, 바이오 플라스틱은 소비자들의 친환경 제품에 대한 관심과 연결되어 국내 플라스틱 산업의 새로운 활로가 될 것으로 기대된다. 이를 위해서는 비교적 초기단계에 있는 국내 친환경 바이오 플라스틱 기술에 대해 기업과 대학에서 활발한 연구가 이루어져야 할 것으로 보인다. 빠르면 2-3년 내에 기존 생분해 플라스틱 이외에 바이오 베이스 및 산화생분해 플라스틱을 주원료로 한 식품용기 및 포장재, 산업용품, 농업용품, 일회용품, 산업용랩, 스트래치 필름 및 각종 상품용 제품이 실용화되고, 장기적으로는 생체 의료용제 등과 같은 첨단의 고부가 생명 공학기술을 응용한 다양한 종류의 환경 친화 제품의 출시가 예상되며, 향후 바이오 플라스틱 산업은 시장 잠재력과 성장성이 무한한 환경 관련 사업으로 평가된다.

• Design & Manufacturing
• /
• 제17권4호
• /
• pp.33-41
• /
• 2023

Excessive use of plastic bottles contributes to a significant environmental issue due to the high volume of plastic waste generated. To address this, efforts are needed to reduce the weight of plastic bottles. However, indiscriminate weight reduction may compromise the essential rigidity required for plastic bottles. Extensive research on rib shape for pressure vessels are exists, but there is a few research of rib shapes to enhance the stiffness of plastic bottles. The following results were obtained from the analyses conducted in this study. 1) Among the rib cross-sections of square, trapezoid, and triangle, the buckling critical load of PET bottles with square-shaped ribs is improved by about 14% compared to the buckling critical load of PET bottles without ribs. 2) The buckling critical load is improved by about 18% when a square-shaped rib with an aspect ratio of 0.2 is applied, compared to the buckling critical load of the bottle without the rib. 3) When longitudinal and transverse square ribs were applied to the axial direction of the PET bottle, the buckling critical load was improved by about 32% and 58% compared to the buckling critical load of the PET bottle without ribs, respectively, indicating that applying longitudinal ribs is effective in reinforcing the stiffness of PET bottles. 4) When 14 transverse ribs were applied, the maximum improvement was about 48% compared to the buckling critical load of the plastic bottle without ribs. 5) When 3 longitudinal ribs were applied on each side, the maximum improvement was about 76% compared to the buckling critical load of the bottle without ribs. Therefore, it was concluded that for effective stiffness reinforcement of a 500ml square bottle with a thickness of 0.5mm, 3 square-shaped ribs with an aspect ratio of 0.2 should be applied in the longitudinal direction relative to the axial direction of the bottle.

• KIEAE Journal
• /
• 제8권5호
• /
• pp.61-68
• /
• 2008

For the recycling of the resources and the preservation of the environment, this study's purpose is to measure flexural behavior of the reinforced concrete beams with the major variables like concrete strength, replacement ratio of the recycled aggregate and the waste foundry sand and the tension reinforcement ratio and to present the data of the recycled aggregate used for the structure design. The experiment on the flexural behavior resulted in the followings. The ultimate strength of recycled R/C beam was manipulated proportionate to the tension reinforcement ratio, however the strength instantly decreased after passing the ultimate load due to the destroyed concrete of the compression side. The deflection at the maximum load varied from the tension reinforcement ratio by 5.5 times. The test specimen with the tension reinforcement ratio less than $0.5{\rho}b$ showed constant curve without change in the load from the yield to the ultimate load in contrast to the distinctive plastic region where the displacement was rising. Although the strain of main tension steel with the reinforcement ratio indicate different, the design of recycled concrete member can be applied for current design code for reinforced concrete structure as the ratio of tension reinforcement district the under the reinforcement ration in a balanced strain condition.

• 에너지공학
• /
• 제29권3호
• /
• pp.34-41
• /
• 2020

Used disposable diapers have been considered for a long time as a type of waste difficult to recycle and valorize due to their composite nature including plastic, cellulose pulp, a super absorbent polymer and either urine, feces or both. Therefore, the fate of disposed diapers often is either incineration or landfill burial which both have various adverse environmental impacts. However, used disposable diapers contain nutrients: cellulose is an organic matter while urine and feces contain non negligible amounts of nitrogen, phosphorus and potassium which are primary nutrients included in most chemical fertilizers used in agriculture. In a scope of waste recycling and valorization, this study focuses on developing a method to achieve nutrient solution extraction from used disposable diapers. The experiment essentially consists in shredding the diapers and letting them macerate in solutions of sodium hydroxide with various concentrations to allow breaking down of the cellulose and super absorbent polymer and release of urine and feces before sterilizing the solutions in an autoclave to remove potential coliform bacteria. At the end of the experiment, a set of parameters is measured for the final solution to identify concentrations of nutrients as well as presence or absence of harmful substances. Results are discussed and directions for future studies are suggested, which include mechanization of the diapers shredding process or added aeration to enhance nitrification and absorption of extracted nutrients from plants.

• 산경연구논집
• /
• 제8권3호
• /
• pp.5-9
• /
• 2017

Purpose - While sustainability is based on the argument that the world's resources are finite and their demand will ultimately surpass supply, entrepreneurship on the other hand argues that there are inherent opportunities to address this through conserving, recycling, switching to more renewable resources and making effective use of available finite resources. Research design, data, and methodology - In response to the lack of scientific information on the outcomes of entrepreneurship in rural Nigeria, this paper surveys the benefits (social, economic and environmental) of women engagement in waste plastic bags recycling in Adamawa State of Nigeria. A descriptive research design was adopted and data was collected from 26 respondents with the use of a semi-structured questionnaire, which was analyzed using descriptive statistics and presented in frequency tables. Results - Results indicated that 21 women have gained employment, who would have remained unemployed; 80.8% of who make profits below 10000 Naira per month and collectively, they recycle 179.3kg of waste polythene bag per month. Conclusions - It was recommended that the women should be further their education; adequate records of costs and sales should be kept; and savings should be encouraged among them.

• 한국가구학회지
• /
• 제27권2호
• /
• pp.80-90
• /
• 2016

The idea of Sustainable, first mentioned in "Our Future (Bruntdland)" from the United Nations report released in 1987 has been highly affect design disciplines in developed countries in 21st century. It relocated industrial society and structure's attentions to nature and recourse conservation and reuse. Designed and manufactured products eventually disposed and it leads to waste of resources as well as creates environmental issues. Unfortunately, vast majority of designers starts designing without anticipation of this matter and produce more believing this leads to more sales. However shorter life of a product will create bigger increase of resource consumption and waste than, importance of re-usage and recycle will eventually increase. In modern furniture industry metal and plastics are frequently used beside wood that material has been diverse than in past. However, there are lack of plans and regulations of re-usage of those material due to difficulties of separating each different materials and collecting due to it's size. This study would like to look into recycling rate, methods and usage of three major materials (wood, metal, plastic) that is typically used in current furniture industries. Furthermore, see the potential of sustainable furniture by analyzing furniture practices made by each different recycled material from old furniture and what designers should consider to achieve feasibility of sustainable furniture.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
• /
• pp.25-26
• /
• 2019

The construction of adobe houses in flood prone areas is a common practice. These houses collapse when hydraulic loads from flood exerts on the houses. The failure occurs because the adobe brick lacks strength. In order to improve strength of adobe brick, the effects of agriculture waste therefore rice straw, rice husk and rice husk ash as a stabilizing agent have been explored in this paper. The compressive strength test and splitting test was conducted on the adobe specimens which were stabilized with 2% rice straws, 2% rice husk and 2% rice husk ash by the dry weight of soil. The results showed the improvement in strength and elasticity of specimens containing rice straws & rice husk. Whereas with the addition of rice husk ash, the adobe loses its strength and showed plastic behavior.