Earticle

본 연구에서는 PP/EVOH 다층 구조 식품 포장 용기를 재활용한 후 발생하는 용출물 특성과 생물학적 안전성을 종 합적으로 평가하였다. PP/EVOH 식품 포장 용기 재활용 과정에서 발생하는 화학적 변화는 용출물 특성에 중요한 영 향을 미치며, 재활용 후 식품 포장 용기의 안전성을 저해할 수 있는 잠재적 위험 요소로 작용할 수 있음을 확인하였다. 본 연구는 재활용 식품 포장 용기 안전성 평가를 위한 기 초 자료를 제공하며, 향후 재활용 공정에서 화학적 안정성 과 생물학적 안전성 확보를 위한 보다 엄격한 기준 마련이 필요성을 제언한다.

This study investigates the increase in chemical leachates and the biological toxicity associated with repeated recycling of multilayer plastic food packaging composed of polypropylene (PP) and ethylene vinyl alcohol (EVOH). Based on the ISO 10993-5 cytotoxicity assay, a slight level of cytotoxicity was detected in the recycled samples, indicating a potential biological risk associated with the use of recycled materials. Chemical analyses using ICP, pH meter, balance, UV, UV/VIS spectrophotometer confirmed a cumulative increase in the total amount of leachates. Notably, the accumulation of heavy metals was identified in the recycled plastics, which was attributed to metal components originating from the shredding and reprocessing equipment used during recycling. SEM-EDX analysis further confirmed that the accumulated metals matched the elemental composition of the recycling equipment. These findings highlight the potential accumulation of heavy metals derived from processing machinery during the recycling of multilayer packaging and underscore the need for establishing safer and more controlled recycling systems.

In this study, the effective active ingredients of coffee waste extract and the caffeine content of coffee waste were confirmed using a high pressure hydrothermal extraction method to confirm the potential of coffee waste as a circular resource and a recycling material. In order to determine whether extraction of coffee waste affects caffeine reduction, ethanol content was soaked at room temperature for 48 hours at ratios of 0%, 30%, 50%, 70%, 100%, and then extract by high pressure hydrothermal extractor. As a result of quantitative analysis of caffeine on coffee waste using LC-MS, a caffeine reduction rate of 54.7% was confirmed in the coffee waste recovered after extraction with 70% ethanol hydrothermal extractor. Additionally, based on the results of a preliminary experiment that confirmed the highest caffeine reduction rate in high pressure hydrothermal extracted coffee waste with 70% ethanol content, in this experiment, extraction was repeated 3 times using coffee waste with 70% ethanol content in the same method as the preliminary experiment proceeded. Based on the results of a previous experiment that confirmed the highest caffeine reduction rate in hot water-extracted coffee waste with ethanol content of 70% in this experiment additional extraction was repeated three times using coffee waste with an ethanol content of 70% using the same method as the previous experiment. As a result of quantitative analysis of caffeine in coffee waste using LC-MS in this experiment, a high reduction rate of 98.7% of caffeine content was confirmed to be removed from coffee waste recovered by repeated extraction with 70% ethanol three times. The Korean Ministry of Food and Drug Safety confirmed that decaffeination, which removes 90% of the caffeine content, is possible with just two repeated experiments of coffee bean extraction. Therefore, it is expected that application to decaffeinated recycled products will be possible through repeated extraction of coffee grounds, which are discarded waste.

한국 시설원예 농업과 수경(양액)재배 방식은 증가하는 추세로 발생되는 배액(폐양액)의 관리 필요성이 확대되고 있 다. 본 연구에서는 배출되는 폐양액의 비료 성분 양을 가격으로 평가하여 수처리비용 절감과 비료성분 재활용이라는 두가지 측면에서 기술개발과 활용 가능성을 알아보았다. 연구는 배출 배액의 수질환경 특성을 분석한 선행연구에서 제시한 분석결과를 바탕으로 비료성분의 유실 경제성을 평가하는 것으로 배출되는 배액의 총 배출량은 연간 259.7L･ m2･-1을 적용하여 분석에 사용하였다. 토마토, 파프리카, 오이, 딸기 등 작물별 배액(폐양액)의 주요 수질 분석 결과 를 바탕으로 평가하였으며, 인(P) 성분의 경우 인산(P2O5)의 양으로 환산하여 분석되었다. 질소(N)의 양은 토마토 1145.90kg･ha-1, 파프리카 920.43kg･ha-1, 오이 804.16kg･ha-1, 딸기가 405.83kg･ha-1로 평가되고 P2O5의 비료성분 은 파프리카 830.65kg･ha-1, 토마토 622.32kg･ha-1, 오이 477.67kg･ha-1, 딸기 240.9･ha-1의 양만큼 배출하는 것으 로 계산할 수 있다. 이 외에도 칼륨(K), 칼슘(Ca), 마그네슘(Mg)을 비롯해 철(Fe), 망간(Mn) 등 미량원소도 배출되는 것으로 분석되었다. 시중판매 비료가격을 기준으로 평균하여 계산한 항목별 kg당 가격은 질소(N) 860.7원, 인(P) 2,378.2원, 칼륨(K) 2,121.7원, 칼슘(Ca) 981.2원, 마그네슘(Mg) 1,036.3원, 철(Fe) 126,076.9원, 망간(Mn) 6,232.1 원, 아연(Zn) 15,825.0원, 구리(Cu) 31,362.0원, 붕소(B) 4,238.0원, 몰리브덴(Mo) 149,041.7원으로 평가할 수 있다. 시중판매 비료가격을 기준으로 평균하여 계산한 항목별 kg당 가격과 앞서 분석한 작물별 폐양액의 농도, 수경재배의 평균적인 연간배출량 등을 종합적으로 고려하여 연간 유실되는 작물별 비료 유실액을 산출하였다. 분석결과 토마토의 경우 6,995,622.3원, 파프리카는 7,384,923.8원, 오이는 5,091,607.9원의, 딸기는 2,429,290.6원으로 평가되어 수경재 배 4가지 작물 평균은 1ha 재배면적 기준 5,475,361.1원의 비료성분 유실이 확인되었다. 수경재배 배액을 하천으로 유출시켜 오염원으로 처리하는것 보다 배출 전 자체 처리 또는 타작물 활용을 통해 관리한다면 수처리 비용 절감과 더불어 가치있는 재이용 가능한 비료성분이 될 수 있다고 기대하였다.

Korean facility horticulture and hydroponic cultivation methods increase, requiring the management of waste water generated. In this study, the amount of fertilizer contained in the discharged waste liquid was determined. By evaluating this as a price, it was suggested to reduce water treatment costs and recycle fertilizer components. It was evaluated based on the results of major water quality analysis of waste liquid by crop, such as tomatoes, paprika, cucumbers, and strawberries, and in the case of P component, it was analyzed by converting it to the amount of phosphoric acid (P2O5). The amount of nitrogen (N) can be calculated by discharging 1,145.90kg･ha-1 of tomatoes, 920.43kg･ha-1 of paprika, 804.16kg･ha-1 of cucumbers, 405.83kg･ha-1 of strawberries, and the fertilizer content of P2O5 is 830.65kg･ha-1 of paprika, 622.32kg･ha-1 of tomatoes, 477.67kg･ha-1 of cucumbers. In addition, trace elements such as potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), and manganese (Mn) were also analyzed to be emitted. The price per kg of each item calculated by averaging the price of fertilizer sold on the market can be evaluated as KRW, N 860.7, P 2,378.2, K 2,121.7, Ca 981.2, Mg 1,036.3, Fe 126,076.9, Mn 62,322.1, Zn 15,825.0, Cu 31,362.0, B 4,238.0, Mo 149,041.7. The annual fertilizer loss amount for each crop was calculated by comprehensively considering the price per kg calculated based on the market price of fertilizer, the concentration of waste by crop analyzed earlier, and the average annual emission of hydroponic cultivation. As a result of the analysis, the average of the four hydroponic crops was 5,475,361.1 won in fertilizer ingredients, with tomatoes valued at 6,995,622.3 won, paprika valued at 7,384,923.8 won, cucumbers valued at 5,091,607.9 won, and strawberries valued at 2,429,290.6 won. It was expected that if hydroponic drainage is managed through self-treatment or threshing before discharge rather than by leaking it into a river and treating it as a pollutant, it can be a valuable reusable fertilizer ingredient along with reducing water treatment costs.

본 연구에서는 대전시 공공미술 프로젝트 <무궁화 꽃이 피었습니다> 사례연구를 통하여 열악한 주거환경에서 지역공동체를 만들기 위한 공공미술 프로젝트 운영방법을 모색한다. 문헌연구를 바탕으로 지역공동체를 모아내는 공공미술의 세 가지 측면으로 시각성, 특수 성, 소통성을 도출하였고, 이러한 요소들을 기반으로 방문자, 예술가, 지역주민, 기획자 등 연구대상 이해관계자를 심층 인터뷰하여 사례를 분석하였다. 분석결과로 첫째, 주민들의 재활용 쓰레기로 함께 만든 공공미술은 시민과 환경을 효과적으로 조화시키고 통합하고 있었다. 둘째, 프로젝트의 일환으로 운영되는 갤러리는 시민들이 지역의 역사와 상징을 이 해하게 함으로써 지역 정체성 강화에 상당한 역할을 하고 있었다. 셋째, 지역공동체와의 소 통공간으로 마련된 공방은 시민들의 자발적인 공동체 참여를 활성화하는 데 일조하고 있 었다. 상대적으로 기관과의 연구 협력에 관한 인식은 크게 부각되지 않았는데, 이는 열린 공동체라는 가치적 측면에서, 더 다양한 예술 형식에 열려있는 자세로 다른 지역과의 문화 적 연계를 구축하고 지속적인 협력이 필요하다는 점을 시사하고 있다.

The purpose of this study is to find methods for building the community in poor residential environments. We analyze the public art project, “The Rose of Sharon Blooms,” in Daejeon. To understand the project we interviewed artists, curators, local residents, and visitors, about three aspects of public art: visuality, speciality, and communication with citizens. These stakeholder interviews yielded valuable knowledge and insights: First, artworks created from the residents’ recycled junk effectively harmonizes and unifies the citizens and their environment. Second, managing a gallery in the neighborhood symbolically values and explicates the public art project and thus enhanced the local identity. Third, public workshops in the neighborhood provide a venue for local citizens to communicate with visitors about the public arts, which eventually led to the welcoming atmosphere of the community. However, we found relatively little awareness of the need for partnership aspects among our interviewees, which suggests the importance of ongoing cooperation with other arts institutions and researchers to build vital cultural linkages and introduce varied art forms.

최근 급속한 산업화로 인하여 자원 문제와 환경문제가 대두되고 있다. 이에 따라 태양전지가 발달하여 위의 문제를 어 느 정도 해결하였지만, 1990년도부터 보급된 모듈이 15~20년의 수명으로 인하여 현재 폐 태양전지모듈 발생으로 인한 토양오염 문제가 급부상하고 있다. 폐 태양전지 모듈 발생량이 증가할 것으로 예상됨에 따라 폐 태양전지 모듈로부터 실 리콘 회수에 관한 연구를 수행하였다. 태양전지 모듈은 은(Ag), 실리콘(Si), 알루미늄(Al) 등으로 이루어져 있다. 태양전 지로부터 실리콘(Si)을 회수하기 위해서 인산과 질산을 사용하였으며, 100oC에서 2 M의 인산을 이용하여 99.99%의 Al 을 제거할 수 있었으며, Ag의 경우 40oC에서 2 M의 질산을 이용하여 99.99% 제거할 수 있었다. 또한, EDS(Energydispersive X-ray spectroscopy)와 ICP(Inductively Coupled Plasma)를 이용하여 유가금속(Al, Ag)과 실리콘(Si)의 순도 를 분석하였다.

Resource and environmental problems are emerging due to rapid industrialization. As a result, although solar cells have developed and solved the above problem to a certain extent, the soil pollution problem caused by generation of waste solar cell modules has emerged due to the life of 15 to 20 years of the modules supplied since 1990. As the generation of waste solar cell module is expected to increase, a study on the recovery of silicon from the waste solar cell module was carried out. The solar cell module is composed of silver (Ag), silicon (Si) and aluminum (Al). Phosphoric acid and nitric acid were used to recover silicon (Si). The removal ratio of Al from the solar cell was 99.99% using 2 M phosphoric acid at 100oC. In case of Ag, the removal ratio was 99.99% using 2 M nitric acid at 40oC. We also analyzed the purity of valuable metals (Al, Ag) and silicon (Si) using Energy Dispersive X-ray Spectroscopy (EDS) and Inductively Coupled Plasma (ICP).

Organic compounds have a problem that the separation of structural isomer in the preparation process requires high energy consumption. This study proposes a new separation method of structural isomer using Magneto- Archimedes method. Firstly, the levitation height of 1, 6-DDA and 1, 10-DDA was respectively calculated by simulation of the forces acting on the particles under magnetic field, and it was indicated that they could be separated by the difference of levitation height. To confirm the phenomenon experimentally, white powders of 1, 6-DDA and 1, 10-DDA were formed into pellets, and were soaked in manganese chloride solution. Then the solution was put on the center of the cryostat of HTS bulk magnet (maximum magnetic flux density is 3T). As a result, it was confirmed that the separation of structural isomer by difference of levitation height could be possible.

The technologies using magnetic force control have been investigated toward application in various fields. Some of them have been put into practical use as the results of technological development. This paper introduces our technical development in the field of water processing, scale removal, magnetic drug delivery system, decontamination of radioactive substances and resources recycling.

The waste substrate from sawdust based cultivation of Heicium erinaceum was reused. This process was conducted three times. Even when the waste substrate was reused at three times, the yield of fruiting bodies was equal to that of fresh medium. However, the yield of the 1st-waste substrate was the best of all waste substrate media and the yields of waste substrate media deceased with recycling times. The yield of the 1st or the 2nd waste substrate medium increased by 1.3-1.4 times compared with that of the fresh medium. The content of low molecular α-glucan and β-glucan of the 1st or the 2nd waste substrate medium increased and C-N ratio of the 1st or the 2nd waste substrate medium decreased. These results suggest that low molecular glucan and N sources contribute to increasing fruiting bodies. It was clear that the 1st and the 2nd waste substrate were useful for the cultivation material of Heicium erinaceum.

이 연구는 폐 PE / PET / TPE 상용화에 따른 특성에 초점을 맞추었다. 재활용 PET/HDPE blend의 단점인 내열특성과 충격강도 특성이 개선되었고, 내열특성은 polyester계 폐TPE를 첨가한 것이 HDPE가 첨가된것 보다 50℃이상 높은 150℃이상을 나타내었다. Elastomer의 적용으로 충격강도가 현저히 증가되어 내열 및 탄성이 요구되는 산업분야에 적용할 수 있는 안전소재로의 적용가능성을 확인할 수 있었다. 또한 상용화제를 이용하여 PET를 블렌드 함으로써 폴리올레핀계 수지의 강도를 향상시켰다. 폐HDPE와 폐PET blend의 기계적 물성이 크게 향상되었으며, morphology 특성에서도 상용화제의 첨가에 따라 분산상의 크기가 감소하고 균일해짐이 관찰되었다.

This study focused on the characterization of recycle PE/PET/TPE blend with compatibilizers. The heat resistance and impact strength of a weak point on PET / HDPE blend has been improved. TPE added polyester-based recycle heat-resistant properties to 150℃ showed more than 50℃ higher than HDPE added. Elastomer applied is a significant increase in the impact strength, and then it is possible to apply for safety materials in industries requiring heat-resistance and elasticity. Also using PET blend compatibilizer improves the strength of the polyolefin resin. The mechanical properties of recyle HDPE and PET blend has been greatly improved, and the reduction in the size of the dispersed phase by the addition of compatibilizers on morphology characteristics were observed uniformity becomes.

This review paper provides a detailed analysis of PET (polyethylene terephthalate) bottle recycling in Japan. Japan is a global leader in PET bottle recycling due to its advanced regulatory framework and proactive industry initiatives. Japan's success attributes to the widespread adoption of bottle-to-bottle recycling, driven by the beverage industry's commitment to sustainability. By utilizing post-consumer PET bottle recovery and food-grade mechanical recycling technologies, Japan has achieved significant milestones in PET bottle recycling. This paper examines regulatory frameworks, collection systems, reprocessing facilities, and food safety assessments to highlight Japan's innovative approaches to PET bottle recycling and their impact on global sustainability efforts. Drawing parallels with Korea's early stages of PET recycling, it suggests involving major beverage companies and re-evaluating regulations to promote bottle-to-bottle recycling. The focus is on the implications for Korea to promote circular economy principles in plastic recycling.

본 연구는 하수처리장 반류수의 생물학적 및 화학적 처리공정을 이용하여 효율적인 질소와 인을 처리하기 위하여 SDR(Sulfur Denitrification Reactor)을 적용하였다. 황-이용 탈질반응은 무산소 조건에서 Thiobacillus denitrificans와 같은 독립영양탈질균들이 황을 이용하면서 질산성 질소(NO3-N)를 질소가스로 전환시켜 탈질반응을 수행한다. 연구결과 황-이용 탈질은 pH 7.0~8.5의 조건에서 높은 탈질율을 보였으며, 탈질반응에 소요되는 알칼리도 양과의 관계는 1 mg의 질산성 질소를 환원하는데 약 3.3 mg의 알칼리도가 소요되었다. 황-이용 탈질은 처리대상과 접촉면적, 수리학적 체류시간에 따라서 탈질에 영향을 미친다. SDR의 수리학적 체류시간을 1.0 hr, 1.5 hr, 2.0 hr로 하여 탈질율을 비교해본 결과 1.0 hr에서 높은 처리효율 보였다. 황-이용 탈질은 탈질이 진행됨에 따라 황산염 이온이 발생되며, 1 mg의 질산성 질소를 탈질시키는데 7.21 mg의 황산염 이온이 발생한다. 본 논문을 통해 SDR을 이용한 고농도의 질산성 질소의 탈질과 화학적 인의 처리가 가능하였으며, 향후 질산화-황탈질 공정을 설계하여 안정적인 반류수의 처리가 가능할 것으로 판단된다.

This study applied SDR (Sulfur Denitrification Reactor) in order to handle nitrogen and phosphorus efficiently through biological and chemical treatment processes of recycled water. Sulfur denitrification reaction in SDR is performed by autotrophic denitrification bacteria such as Thiobacillus denitrificans, which utilizes sulfur and converts nitrate-nitrogen (NO3-N) to nitrogen gas in anaerobic conditions. The findings were that denitrification using sulfur showed high rate of denitrification under conditions of pH 7.0~8.5. For relationship between the amount of alkalinity consumed in a denitrification reaction, approximately 3.3mg of alkalinity was consumed to denitrify 1 mg of nitrate-nitrogen. Denitrification using Sulfur is affected by the contact area with objects to be treated, the hydraulic residence time affects denitrification. SDR's hydraulic residence time (HRT) was set as 1.0 hr, 1.5 hr, 2.0 hr respectively and then the denitrification rate was compared. The results showed high treatment efficiency at 1.0 hr. 7.21 mg of sulfate ions is produced in order to denitrify 1mg of nitrate nitrogen. Through this paper, treatment of high concentrations of nitratenitrogen,, chemical phosphorus was possible using SDR Denitrification. Stable recycled water treatment is thought to be possible by designing nitrification - sulfur denitrification process in a future.

The lightweight foamed concrete specimens are made by mixing cement, gypsum, Manganese dioxide(MnO2), hydrogen peroxide, water, PP, Also, we study the physical and mechanical properties of lightweight formed concrete through diverse experiment which is to determine the optimal mixing proportion and require strength of the lightweight formed concrete. As a result of an experiment, Steel fiber is mixed, did not affect the strength, PP, increasing the amount of the compressive strength, flexural strength was increased.

원자력발전소 해체 시 발생하는 금속폐기물은 폐기물 중에서 많은 비중을 차지하고 있다. 본 연구에서는 국내 자체처분 규제 요건 및 국내 기관별 자체처분현황을 조사하였다. 실제 원자력발전소 해체 시 발생되는 금속폐기물의 자체처분을 위하여 RESRAD-RECYCLE 코드를 이용하였으며 26가지 시나리오에 대한 선량평가를 수행하였다. 평가결과는 원자력발전소 해체 시 자체처분 및 재활용에 관한 사전자료로서 활용가치가 있을 것으로 사료된다. 추후 자체처분을 통한 처분비용 저감효과 연구가 추가로 가능할 것으로 판단된다.

The metal waste generated during nuclear power plant decommissioning constitutes a large proportion of the total radioactive waste. This study investigates the current status of domestic and international regulatory requirements for clearance and the clearance experience of domestic institutions. The RESRAD-RECYCLE code was used for analyzing the clearance of the metal wastes generated during actual nuclear power plant decommissioning, and assessment of the exposure dose of twenty-six scenarios was carried out. The evaluation results will be useful in preliminary analysis of clearance and recycling during nuclear power plant decommissioning. As a next step, the effects of reducing disposal costs by clearance can be studied.