최근 전기차 및 전력저장 시스템과 같은 대형 전지 시장의 성장으로 인해 리튬 이온 배터리에 대한 수요가 급증하 고 있다. 이에 따라 폐전지의 발생이 빠르게 증가할 것 으로 예상되며, 이에 대한 처리가 사회적 문제가 될 것 으로 예상된다. 폐전지 처리의 가장 효과적인 방법은 폐전지의 소재를 재활용하는 방법이다. 이 중 고가의 금속 물질로서, 재활용 시 경제성이 가장 높은 양극 소재 재활용 연구가 가장 활발히 이뤄지고 있다. 하지만 폐전지로부터 회수된 블 랙 파우더에는 도전재 및 바인더가 포함되어 있는데 양극 소재를 재활용하기 위해서는 이를 제거하는 공정이 필요하 다. 본 연구에서는 폐전지에서 추출된 폐양극 소재의 재활용을 위한 소재 전처리 연구를 제시한다. 열처리 및 화학 처리의 두 가지 전처리 공정을 사용하여 불순물을 제거하였고, 이에 따른 제거 정도를 SEM 분석을 통해 확인하였고, 불순물의 정량 분석을 TGA, EA 분석을 통해 확인하였으며, 전기화학 성능을 분석하였다.

내구연한이 도래한 아스팔트 혼합물은 사용자의 주행성 및 안전성 확보를 위해 주기적인 유지·보수를 실시한다. 과거에는 유지·보수 과정에서 발생된 폐아스팔트 혼합물을 각종 건설현장에서 단순 매립재로서 활용하였으나, 재활용 아스팔트 혼합물의 배합설계 기술이 확립된 이후에는 도로포장재료로서의 재활용되어왔다. 하지만 현재 시공된 재활용 아스팔트 혼합물 또한 내구연한이 다가옴에 따라 노화된 재활용 아스팔트 혼합물의 처리방안 수립이 필요한 시점이다. 본 연구에서는 한번 재활용된 아스팔트 혼합물이 기존의 재활용 배합설계법으로 반복적인 재활용이 가능한지 검증해보고자 하였다. 이를 위해 아스팔트 혼합물의 물성을 결정하는 가장 큰 요인 중 하나인 아스팔트의 물성이 노화 및 재생을 반복할때 어떻게 변하는지를 시험을 통해 분석하였다. 아스팔트 바인더의 노화를 모사하기 위해 공용성등급시험에 사용되는 단기노화 장비(Rolling Thin Film Oven, RTFO)와 장기노화 장비(Pressure Aging Vessel, PAV)을 활용하 였다. 노화된 아스팔트의 회생을 위한 재생첨가제 사용량은 국토부 시공지침의 배합설계법을 참고하였다. 실험결과, 노화된 바인더는 회생시 원바인더에 비해  sin는 감소하였으나, 회생된 바인더 간에는 유사한 결과값을 보였다. 반면 단기노화 시료는 회생이 반복 됨에 따라  sin이 감소한 경향을 보였으며, 장기노화시료는 회생이 반복되어도  sin가 유사한 것으로 확인되었다.

교통량이 증가하고 교량과 같은 특수구조물에 아스팔트 포장이 시공되는 사례가 증가함에 따라 일반적으로 사용되는 아스팔트보다 높은 성능을 가진 아스팔트에 대한 수요가 증가하고 있다. 일반 아스팔트 혼합물은 내구연한이 지나면 재생첨가제 등을 사용하여 다 시 도로포장재료로서 재활용할 수 있는 방안이 마련되어 있으나, 개질 아스팔트가 사용된 폐아스팔트 혼합물은 매립재로 사용하는 것 이외에는 별다른 대안이 없는 실정이다. 이에 본 연구에서는 국토부 지침에 규정된 재활용 아스팔트 혼합물 배합설계법을 적용하여 개질 폐아스팔트 혼합물을 재활용할 수 있는지를 검토해보고자 하였다. 이를 위해 개질 아스팔트를 활용하여 혼합물을 제작하였으며, 현장에서 수거되는 폐아스팔트 혼합물의 노화상태를 모사하기 위해 AASHTO R 30을 참고하여 강제 노화를 실시하였다. 노화 및 추출 과정에서 아스팔트의 물성 변화를 확인하기 위해 절대점도, DSR, MSCR 시험을 실시하였다. 시험결과, 추출 후 바인더의 절대점도는 감소하였으나 G*(복합전단계수)와 δ(위상각)은 증가하는 경향을 보였다. 소성변형 저항성을 확인하기 위해 MSCR(다중 응력 크리프 및 회복) 시험을 실시한 결과,  이 2배 가까이 증가하여 소성변형 저항성이 감소한 것을 확인할 수 있었다. 이러한 결과는 추출시 사용 되는 용매가 개질첨가제를 추출하지 못하여 기인한 결과로 판단된다. 따라서 개질 폐아스팔트 혼합물을 재활용하기 위해서는 기존과 는 다른 별도의 배합설계법이 개발되어야 할 것으로 판단되었다.

Around the 1980s, with government’s promotion and dissemination policies for FRP (Fiberglass Reinforced Plastics) of the government as a main material of fishing boats, approximately 97% of the entire fishing boats in Korea have utilized FRP until now. Nevertheless, diverse social and environmental issues have emerged due to the susceptibility to fire and the generation of substances detrimental to human health during the construction process of FRP fishing vessels. Especially, the high disposal cost and the limitation of recycling technology in the disposal process of FRP fishing boats have elicited attention to circular economy. This research intended to grasp the management status and problems of disposed FRP fishing boats in Korea, and to assess the level of competitive advantage of FRP fishing boats’ recycling technologies of FRP fishing boats based on VRIO (Value, Rarity, Imitability, Organization) analysis through domestic and foreign management policies and related recycling examples. According to the survey of 161 respondents, including the industry, stakeholders and experts related to the collection, treatment and recycling of fisheries wastes, it was revealed that FRP fishing boats’ recycling technologies of FRP fishing boats are at the level of ‘unused competitive advantage’ that satisfied the level of value, rarity and imitability, but not the level of organization.

Electronic waste (E-waste) has become a long-standing global concern. People are purchasing new affordable and improved technologies long before the end-of-life (EOL)’s of their old devices, which is leading to overconsumption and growing volumes of e-waste. At present, official data indicates that 80% of the volume of e-waste is not formally treated globally. The complex nature of e-waste recycling processes is a significant challenge.

우리나라 폐기물관리법상 의료폐기물은 소각 또는 멸균분쇄 후 소각하도록 되 어 있으나, 멸균분쇄 후 소각하는 경우는 미미하다. 의료폐기물은 멸균분쇄 하 더라도 위해성이 남아 있다는 전제하에 잔재물을 소각해야 한다는 법률규정 때문에 멸균분쇄는 불필요한 과정으로 인식되어 대부분 의료폐기물 전용소각 장에서 소각되고 있다. 그러다보니 의료폐기물 전용소각장의 처리용량이 부족 해지고, 이를 해결하기 위하여 법정한도를 초과해서 처리하는 것을 허용하는 경우도 있으며, 감염정도가 낮은 일회용기저귀는 폐기물관리법 특례를 적용하 여 의료폐기물에서 제외하여 일반폐기물 소각장에서 처리하고 있다. 국내 폐기물관리법은 기계적 처분 방식인 고압증기멸균법 및 마이크로웨이브 멸균법 등이 규정되어 있지만 아직 활성화 되지 못하고 있다. 이는 의료폐기물 처리에 대해 어떠한 방식을 통해서라도 자원을 재활용해야 한다는 당위성에 대한 인식이 부족하기 때문이다. 멸균분쇄 후 남은 잔재물을 소각하지 않고 재활용하기 위해서는 개정되어야 할 규정 들이 많이 있다. 의료폐기물은 발생지인 의료기관이 자가처리 방식으 로 멸균분쇄하여 일반폐기물로 배출하여 재활용하는 것이 가장 바람직한 방법 이다. 따라서, 해외 선진 국가들과 마찬가지로 우리나라도 의료폐기물 재활용, 특히 소재 자체가 활용도가 매우 높은 일회용기저귀에 대해서는 반드시 재활 용 및 재생원료로 사용될 수 있도록 연구, 검토되어야 할 것이다.

RUCAS (Recycling-Underlying Computational Dose Assessment System), a dose assessment program based on the RESRAD-RECYCLE framework, is designed to evaluate dose for recycling scenarios of radioactive waste in metals and concrete. To confirm the validity of the recycling scenarios provided by RUCAS, comparative evaluations will be conducted with RESRAD-RECYCLE for metal radioactive waste recycling scenarios and with MicroShield® for concrete radioactive waste recycling scenarios. In the evaluation of metal recycling scenarios without shielding, RUCAS showed similar results when compared to both MicroShield® and RESRAD-RECYCLE. This validates the function of dose assessments using RUCAS for metal recycling scenarios. However, when shielding was present, RUCAS produced results that were comparable to MicroShield®, but differed from those of RESRAD-RECYCLE. The underestimation of dose values up to 1.66E+08 times difference by RESRAD-RECYCLE could potentially decrease reliability and safety in evaluated doses, further emphasizing the importance of RUCAS. Because validation is also necessary for the expanded calculation capabilities resulting from methodological changes of RUCAS (i.e., various radiation source geometries), based on prior validations, it was determined that additional validations are required for different radiation source materials and shielding conditions. In case where the radiation source and shielding materials were identical, RUCAS and MicroShield® produced similar results according to both the Kalos et al. (1974) and Lin and Jiang (1996) methodologies. This demonstrates that the that differences in methodology are inconsequential when considering the same source and shielding materials. However, when the atomic number of the radiation source materials was larger than that of shielding material (HZ-LZ condition), RUCAS obtained results similar to MicroShield® only for the Kalos et al. (1974) methodology. While Lin and Jiang (1996) methodology yield higher results than MicroShield®. Lastly, in case where the atomic number of the radiation source material was smaller than that of the shielding material (LZ-HZ condition,) both methodologies yielded results comparable to MicroShield®. In conclusion, the validity of RUCAS’s shielding calculations has been verified, confirming improvements in dose assessment compared to RESRAD-RECYCLE. Additionally, we observed that shielding effectiveness calculations differ depending on the methodology of build-up effect. If the validity of these methodologies is confirmed, it is expected that selecting the most advantageous methodology for each condition will enable more rational dose assessments. Consequently, in future research, we plan to evaluate the validity of Lin and Jiang (1996) methodology using particle transport codes based on the Monte Carlo method, such as MCNP and Geant 4, rather than MicroShield®.

Controlling fashion waste throughout the entire product lifecycle is critical in a circular economy. This study explored the possibility of establishing a public recycling system for fashion waste. Since consumer interests and participation are essential, theoretical research, social-text analysis, and quantitative research were conducted to identify consumers’ perceptions of the public recycling of fashion waste and circular fashion. Data were collected via an online survey among women in their 20–30’s living in Korea, and 304 samples were used for data analysis. The results were as follows. First, consumers’ perceptions of recycling fashion waste were composed of recycling difficulty, the need for public recycling, and the need for EPR. Circular fashion perception comprised favor, environment protection, attractiveness, economics, quality and hygiene risks, and lack of diversity. Second, the reuse-recycle attitude and need for EPR affected the favor of all types of circular fashion products. Third, environmental concerns impacted attractiveness, and the favor significantly affected the purchase intention of all types of circular fashion products. In particular, quality and hygiene risk negatively affected the purchase intention of used-fashion products, while attractiveness positively impacted the purchase intention of upcycled-fashion products. The results implied that discussing the public recycling system of fashion waste and EPR policy is imperative. The results also showed the need to classify different types of circular fashion products, such as used, upcycled, and regenerated fashion items, to examine consumers’ perceptions. In addition, the recycling of the fashion waste scale developed in this study could be used for further research.

With a rapid expansion in electric vehicles, a huge amount of the spent Li-ion batteries (LIBs) could be discharged in near future. And thus, the proper handling of the spent LIBs is essential to sustainable development in the industry of electrical vehicles. Among various approaches such as pyrometallurgy, hydrometallurgy, and direct recycling, the hydrometallurgical manner has gained interest in recycling the spent LIBs due to its high effectiveness in recycling raw materials (e.g., lithium, nickel, cobalt, and manganese). However, the hydrometallurgical process not only requires the use of large amounts of acids and water resources but also produces toxic gases and wastewater leading to environmental and economic problems, considering potential economic and environmental problems. Thus, this review aims to provide an overview of conventional and state-of-the-art hydrometallurgical processes to recover valuable metals from spent LIBs. First, we briefly introduce the basic principle and materials of LIBs. Then, we briefly introduce the operations and pros-and cons- of hydrometallurgical processes. Finally, this review proposes future research directions in hydrometallurgy, and its potential opportunities in the fundamental and practical challenges regarding its deployment going forward.

The object of this study is to feasibility assesment for co-digestion efficiency of food waste recycling wastewater(FWR) with thermal hydrolysis process dehydration cake (THP Sludge). As a result of THP pre-treatment experimental conditions to 160oC and 30 minutes, the solubility rate(conversion rate of TCOD to SCOD) of the THP sludge increased by 34%. And the bio-methane potential in the THP sludge increased by about 1.42 times from 0.230 to 0.328 m3 CH4/kg VS compared to the non-pre-treatment. The substrates of the co-digestion reactor were FWR and THP sludge at a 1:1 ratio. Whereas, only FWR was used as a substrate in the digestion reactor as a control group. The experimental conditions are 28.5 days of hydraulic retention time(HRT) and 3.5 kg VS/m3-day of organic loading rate(OLR). During the 120 days operation period, the co-digestion reactor was able to operate stably in terms of water quality and methane production, but the FWR digestion reactor deteriorated after 90 days, and methane production decreased to 0.233 m3 CH4/kg VS, which is 67% of normal condition. After 120 days of the experiment, organic loading rate(OLR) of co-digestion reactor was gradually increased to 4.5 kg VS/m3-day and operated for 80 days. Methane production during 80 days was evaluated to be good at the level of 0.349 m3 CH4/kg VS. As a result of evaluating the dehydration efficiency of the sludge before/after 150-180oC THP using a filter press, it was confirmed that the moisture content of the sludge treated before THP at 180oC was 75% and improved by 8% from 83-85% level. Therefore, it is expected that the co-digestion reactor of FWR and THP sludge will ensure stable treatment water quality and increase bio-methane production and reduction effect of dehydration sludge volume.

In this study, a manual that can be applied to conflict management of clearance waste recycling by stakeholders was researched to recycle clearance waste that is most frequently generated when decommissioning nuclear power plants. In order to develop a manual that can be applied to conflict management, the content of the conflict should be derived first. In order to derive conflict, it is necessary to organize major issues in recycling clearance waste in consideration of domestic nuclear energy and social environment. In order to organize major issues in consideration of the domestic environment, a literature survey and a domestic current situation investigation were conducted. At this time, the subject of the major issue was selected based on the Level 1 influencing factors of the previous study. As a result of the investigation, it was confirmed that there were many major issues due to lack of reliability/understanding in nuclear energy/radiation. Through this Conflicts caused by recycling clearance waste were derived based on the organized issues. As a result of deriving conflicts, eight conflicts were derived below. 1) Reduced business availability due to lack of understanding/reliability 2) Lack of reliability in the selection and technology of nuclide analysis technology 3) Additional time and equipment required due to establishment of clearance waste regulatory requirements 4) Low economic benefits due to reduction in the effect of substituting raw materials 5) Political interference due to worsening public opinion 6) Rejection of final products due to recycling due to distrust of radiation 7) Public acceptance along the transport route from the source to the recycling plant 8) Business promotion deteriorated due to changes in energy policy As a result of the derived conflict analysis, the most conflicts related to lack of reliability/understanding in nuclear energy/radiation were derived. Accordingly, in future research, it is necessary to prepare a specific plan to enhance the understanding of stakeholders about self-disposal waste recycling. Considering that research that can solve the conflicts that will be faced when the domestic/foreign clearance waste recycling industry is activated is not activated, this study is meaningful in that it derived the conflicts that will be faced when recycling clearance waste. Also, it is expected that the conflicts derived from this study will be used meaningfully in the establishment of the clearance waste recycling management manual.

The decommissioning of Kori Unit 1 is expected to generate a large amount of clearance waste. Disposing of a large amount of clearance waste is economically costly, so a recycling method has emerged. However, clearance waste recycling is expected to cause many conflicts among various stakeholders. In the previous study, possible conflicts were selected in consideration of the domestic environment and major issues. Based on this, this study classifies stakeholders involved in conflicts by group, and suggests ways to enhance understanding by stakeholder and enhance reliability. In this study, stakeholders are classified into four groups that share the same conflicts, and each of the following measures is suggested. 1) Stakeholder Engagement. 2) Common understanding of radiation risks, dialogue between the public/recycling industry/ regulatory agency. 3) Incentives to promote recycling clearance waste. 4) Reliable outlet store for recyclable clearance waste. The above understanding enhancement measures are presented so that a solution to conflict can be smoothly derived when designing a clearance waste-related consultative body composed of interested parties in the future. As a more specific solution, measures to enhance stakeholder trust can be suggested for each understanding enhancement measure. Reliability enhancement measures are also presented so that they can be applied to each stakeholder group, and these are as follows. 1) Write a stakeholder engagement plan, Measures for stakeholder participation in measuring the radioactivity concentration of clearance waste. 2) Active use of easy-to-understand radioactivity comparison data, Expansion of information on environmental radiation dose to public, nuclear/radiation education, Held a tour event at the nuclear power plant decommissioning site, New website for clearance waste information disclosure. 3) Incentives for recycling industries in which the Ministry of Environment or KHNP partially bears the losses that occur when the sales rate is low. Incentives are provided to consumers by including recyclables of clearance waste for Green Card’s green consumption points. 4) Online outlets open for recyclable clearance waste with easy-to-understand radioactivity comparison data. It is expected that if the above-mentioned reliability enhancement measures are used, it will be possible to secure the trust of stakeholders and reduce the gap between stakeholders in the future clearance-related consultative body.

Strong acidic wastewater containing a radionuclide is generated from the decontamination of radioactively contaminated wastes or equipment. This wastewater is generally treated though a precipitation process using an alkali (alkali earth) hydroxides. In this precipitation process, a significant amount of alkali (alkali earth) sulfates are generated, which is the reason for the increase in the radioactive waste generation. In this study, a method for separating only radionuclides and metal ions from the wastewater was evaluated. For this reason, precipitation behaviors of radionuclides and metal ions by hydrazine injections were investigated using equilibrium calculations. In addition, behaviors of hydrazine decomposition after removal of radionuclides and metal ions were analyzed for recycling the wastewater.

The number of dismantled nuclear facilities is increasing globally. Dismantling of nuclear facilities generates large amount of waste such as concrete, soil, and metal. Concrete waste accounts for 70% of the total amount of waste. Since hundreds of thousansds of tons of concrete waste generated, securing technology of reduction and recycling of waste is emerging as a very important issue. The objective of this study is to synthesize geopolymer using inorganic materials from cement fine powder in concrete waste. Dismantled concrete waste contains a large amount of calcium silicate hydrate(C-S-H), Ca(OH)2, SiO2, etc., which is an inorganic material required for the synthesis of geopolymer. SiO2 affects the compressive strength of the geopolymer and Ca(OH)2 affects the curing rate. A high concentration of alkali solution is used as an alkali activator, and alkali activator is necessary for the polymerzation reaction of metakaolinite. The experiment consists of three steps. The first step is to react with concrete waste and hydrochloric acid to extract ions. In the solid after filtration, SiO2 and Al2O3 are composed of 84.10%. It can be used instead of commercial SiO2 required for the synthesis of geopolymer. The second step is to add NaOH up to pH 10, impurities can be removed to extract Ca(OH)2 with high purity. The final step is to add NaOH up to pH 13, and Ca(OH)2 extraction. The alkali solution generated after the last reaction can be recycled into an alkali activator during the synthesis of the geopolymer. If dismantled concrete waste is recycled during geopolymer synthesized, the volume reduction rate of dismantled concrete waste is more than 50%. If you put the radioactive waste in the recycled solidification materials synthesis from concrete waste by dismantling of nuclear facilities, it is possible to reduce the amount of waste generated and disposal costs.

This study investigates the preparation of activated carbon fiber derived from waste cotton fabric for economical and ecofriendly recycling as well as its application to water purification. The activated carbon fiber was prepared by physical activation using steam and the adsorption property was then evaluated using methylene blue. When the activation temperature increased, the specific surface area and mesopore volume of the activated carbon fiber increased up to 2562 m2/ g and 0.214 cm3/ g, resulting in the increased adsorption of methylene blue. The results of the adsorption experiment for the activated carbon fiber were analyzed using the Langmuir and Freundlich equations. The Langmuir equation was more suitable than the Freundlich equation to explain the adsorption equilibrium. The maximum adsorption amount of methylene blue was 161.1–731.5 mg/g for fiber samples activated at temperatures ranging from 750 to 950 °C with sample labeled 750SA to 900SA according to the Langmuir equation. The kinetics of methylene blue adsorption by the activated carbon fiber were analyzed using non-linear pseudo-first-order and pseudo-second-order. Sample 750SA was suitable for the pseudo-first-order and 800SA, 850SA, and 900SA sample were suitable for the pseudo-second-order. Therefore, waste cotton fabric has the potential to be the precursor for activated carbon fiber with excellent adsorption properties.

Cobalt is a vital metal in the modern society because of its applications in lithium-ion batteries, super alloys, hard metals, and catalysts. Further, cobalt is a representative rare metal and is the 30th most abundant element in the Earth’s crust. This study reviews the current status of cobalt extraction and recycling processes, along with the trends in its production amount and use. Although cobalt occurs in a wide range of minerals, such as oxides and sulfides of copper and nickel ores, the amounts of cobalt in the minerals are too low to be extracted economically. The Democratic Republic of Congo (DRC) leads cobalt mining, and accounts for 68.9 % of the global cobalt reserves (142,000 tons in 2020). Cobalt is mainly extracted from copper–cobalt and nickel–cobalt concentrates and is occasionally extracted directly from the ore itself by hydro-, pyro-, and electro-metallurgical processes. These smelting methods are essential for developing new recycling processes to extract cobalt from secondary resources. Cobalt is mainly recycled from lithium-ion batteries, spent catalysts, and cobalt alloys. The recycling methods for cobalt also depend on the type of secondary cobalt resource. Major recycling methods from secondary resources are applied in pyro- and hydrometallurgical processes.