Sustainable Solid Waste Landfill: Operational and Management Considerations for Low-Pressure Aeration Landfill Method 지속 가능한 폐기물매립지: 저압 호기성 매립공법 운영·관리 고려사항
송상훈 Sang-hoon Song , 윤상일 Sangil Yun , 김란희 Ran-hui Kim , 이남훈 Nam-hoon Lee , 정민정 Min-jung Jung , 박진규 Jin-kyu Park
DOI:10.9786/kswm.2024.41.4.311
Abstract
Traditional landfill capping methods, which involve a final cover layer, can extend the post-closure care period for several decades, shifting the environmental and economic impacts of landfills to future generations. To promote more sustainable landfills and mitigate the burden on future generations, it is essential to shorten the post-closure care period and reduce methane emissions by employing low-pressure aeration landfill methods. The implementation of low-pressure aeration requires careful consideration of various factors. These include the method of air injection, layout of injection wells, appropriate amount and pressure of air injection, and the control of temperature and moisture content. Additionally, it is essential to consider the emission characteristics of methane and nitrous oxide, establish comprehensive monitoring plans, and set definitive criteria for the completion of landfill aeration. This study reviews the behavior of gaseous carbon and nitrogen and examines the operational considerations crucial for effectively implementing the low-pressure aeration landfill method.
Current Status of Nationwide Response to Direct Landfill Ban in 2030 2030 직매립 금지에 따른 전국적 대응 현황
윤승휘 Seung Hwi Youn , 최희라 Hee Ra Choi , 김나현 Na Hyun Kim , 허가을 Ga-eul Heo , 이평강 Pyeong-gang Lee , 정주원 Ju-won Jeong , 박정훈 Jeong-hun Park
DOI:10.9786/kswm.2024.41.4.326
Abstract
With the continuously increasing volume of waste generation, waste disposal and management have become major social concerns. Waste management policies have therefore been developed with a focus on environmental and economic feasibility. The 2030 direct landfill ban policy, implemented as part of the revision to the Enforcement Rules of the Waste Management Act in July 2021, aims to address these issues. An investigation and analysis of the response status across various regions in the country revealed that most regions chose incineration as the main alternative to direct landfilling. The total capacity of the incinerators, whether operational, under construction, or planned, is estimated to be approximately 21,000 tons/day. In addition to incineration, each region has undertaken recycling, upcycling, and resource circulation campaigns under different names. Resource recirculation is being planned through recycling sorting facilities, waste resource conversion facilities, and energy conversion facilities. However, the development of new incineration facilities faces challenges such as site selection issues and installation delays due to opposition from residents. This situation necessitates active problem identification and resolution efforts by policy authorities. Currently, domestic incineration facilities focus primarily on waste disposal. Therefore, additional research and institutional support at the national level are required to ensure that incineration treatment facilities can operate with consideration of the economic and environmental feasibility of incineration heat energy recovery projects. Furthermore, 41.38% of household waste comprises recyclable resources. However, due to the difficulties involved in selecting, separating, and washing recyclable resources used in the volume-rate system, this method is not a suitable response to the 2030 direct landfill ban. Further research on the economic recovery of recyclables in volume-rate bags is necessary.
A Case Study of Operating Subsidies and Basic Treatment Unit Costs for Public Wastewater Treatment Facilities in Seafood Processing 수산물 가공 공공폐수처리시설 운영보조금 및 처리원단위 사례 분석
조유나 Youna Jo , 최용범 Yongbum Choi , 권재혁 Jaehyouk Kwon , 박준석 Joonseok Park
A Case Study of Operating Subsidies and Basic Treatment Unit Costs for Public Wastewater Treatment Facilities in Seafood Processing 수산물 가공 공공폐수처리시설 운영보조금 및 처리원단위 사례 분석
조유나 Youna Jo , 최용범 Yongbum Choi , 권재혁 Jaehyouk Kwon , 박준석 Joonseok Park
DOI:10.9786/kswm.2024.41.4.343
Abstract
This study analyzes the operating subsidies provided by local governments and the basic treatment unit costs in public wastewater treatment facilities dedicated to seafood processing to generate fundamental reference data. Public wastewater treatment facilities for seafood processing in three local governments in Gangwon Province were selected for this analysis. The characteristics of wastewater from seafood processing revealed that the annual discharge quantity remained relatively stable after 2021, with minimal seasonal fluctuations. This stability suggests no significant difference between the peak and off-peak seasons in the seafood processing industry, likely due to the decrease in domestic fishery catch and increased import dependence. The analysis of the total operating costs revealed that the sludge treatment expenses were the highest, accounting for 33.4% of the costs in local government A. Labor costs were the most significant expenses in local governments B and C, at 28.6% and 39.9%, respectively. Regarding local government subsidies, 34.0% of the total operating costs were covered by local government A, 38.0% by local government B, and 50.5% by local government C. Furthermore, the unit cost of wastewater treatment per ton was calculated to be KRW 5,316/ton for local government A, KRW 3,988/ton for local government B, and KRW 2,051/ton for local government C. Regarding organic matter, the treatment unit cost was the highest for local government C at 1,659 KRW/kg BOD, followed by 1,334 KRW/kg for local government A and 1,177 KRW/kg BOD for local government B.
Review of Cryogenic Grinding Pretreatment for Quality Testing of Solid Refuse Fuels 폐기물 고형연료제품 품질 평가를 위한 동결분쇄 전처리에 대한 검토
최재원 Jaewon Choi , 원필성 Philsung Won , 권상진 Sangjin Kwon , 한민철 Mincheol Han
DOI:10.9786/kswm.2024.41.4.352
Abstract
As the transition toward a circular economy progresses, solid refuse fuel (SRF) technology remains a pivotal recycling method. This technology recycles combustible waste materials like waste plastics and synthetic rubber as sources of heat energy. The SRF quality is significantly dependent on the chemical and physical properties of the base material and the pretreatment processes used. Given the variability in quality test outcomes based on the pretreatment method used, enhancing the representativeness of these tests is crucial. This study introduces cryogenic grinding as a pretreatment step to refine the accuracy of quality testing for SRF. The cryogenic grinding pretreatment of SRF samples resulted in a significant reduction in the mean particle size of the sample by approximately 50 % and the standard deviation by 70% compared with conventional pretreatment methods. This process effectively produces smaller and more uniform samples, which are crucial for reliable quality testing. Additionally, cryogenic grinding pretreatment notably decreased the standard deviation in the results of key quality test parameters, such as the lower heating value, moisture content, and chlorine content, by approximately 80%. This result demonstrates that cryogenic grinding pretreatment can significantly improve the uniformity, representativeness, and reliability of samples for SRF quality testing.
Evaluation of the Effects of Reaction Temperature and Optimization of the Conditions for the Electrochemical Conversion of Sulfate to Persulfate 황산염의 전기화학적 산화를 통한 과황산 합성 반응의 온도 영향 평가 및 생성 조건 최적화
오지민 Ji-min Oh , 정원균 Won-gune Jeong , 조환주 Hwanju Jo , 강찬웅 Chan-ung Kang , 백기태 Kitae Baek
Evaluation of the Effects of Reaction Temperature and Optimization of the Conditions for the Electrochemical Conversion of Sulfate to Persulfate 황산염의 전기화학적 산화를 통한 과황산 합성 반응의 온도 영향 평가 및 생성 조건 최적화
오지민 Ji-min Oh , 정원균 Won-gune Jeong , 조환주 Hwanju Jo , 강찬웅 Chan-ung Kang , 백기태 Kitae Baek
DOI:10.9786/kswm.2024.41.4.362
Abstract
Persulfate is a potent oxidizing agent extensively used as a radical polymerization initiator, bleaching agent, and water treatment agent. Typically, persulfate is synthesized via electrochemical oxidation of sulfate. However, this process is accompanied by Joule heating, which can reduce the efficiency because persulfate is susceptible to activation and decomposition by heat. The precise effect of temperature on electrochemical persulfate production has not been well understood. This study evaluated the effect of temperature on the electrochemical production of persulfate using an H-type water jacket reactor, with reaction temperature set at 15℃, 25℃, 35℃, 45℃, and without temperature control. The results indicated that higher temperatures increased persulfate decomposition, whereas uncontrolled temperature conditions yielded very little persulfate (less than 5% conversion). Notably, production and current efficiency declined sharply above 30℃, with the production rate at 35℃ being 2.57 times lower than at 25℃. Moreover, maintaining a low reaction temperature increased the resistance and reduced the energy efficiency. These results underscore the necessity of temperature control for efficient persulfate production, suggesting that a reaction temperature below 25℃ is optimal for electrochemical persulfate synthesis.
Determination of Organic and Inorganic Impurities in Oyster Shell Wastes Through Thermogravimetric Analysis 열중량분석기를 이용한 방치패각 내 유·무기 이물질 함량 정량화
김석휘 Seokhwi Kim , 이상은 Sangeun Lee , 문현성 Hyunsung Moon , 정윤웅 Yunwoong Jeong
DOI:10.9786/kswm.2024.41.4.370
Abstract
In accordance with the enactment of the Fishery By-products Recycling Promotion Act in July 2022, legal standards were established for the resource conversion of shell wastes containing less than 3 wt% impurities. Oyster shells, primarily composed of calcium carbonate (CaCO3), naturally include impurities from the shucking process. Therefore, an effective analytical method for identifying these impurities is necessary to ensure compliance with the Act. This study aimed to systematize the analytical methods and procedures for quantifying both organic and inorganic impurities in shell wastes using thermogravimetric analysis (TGA). We determined the appropriate analytical conditions for quantifying various impurities based on differential changes in weight loss (Δweight/Δtemperature) resulting from the combustion of organic matter and the decarbonization of CaCO3. The results confirmed that changes in unit weight loss from TGA effectively distinguish the organic fraction in the shell. Additionally, oyster shells undergo a phase transition from CaCO3 to CaO at approximately 580℃. The organic-inorganic impurity-free CaCO3 content, estimated from TGA results, was around 95.5%, with a reliability of ±2.2% when compared to X-ray fluorescence (XRF) analysis. The findings of this study are expected to provide a reliable method for estimating impurity content, thereby facilitating the re-utilization of abandoned shells as a fishery by-product in the future.
The Environmental and Social Impact of Bioplastics and Implications for Their Application in South Korea 바이오 플라스틱의 환경적·사회적 영향 분석과 국내 적용을 위한 시사점
이소라 Sora Yl
DOI:10.9786/kswm.2024.41.4.379
Abstract
Bioplastics are gaining increasing recognition for their potential to replace fossil-based plastics with safer, renewable, and environmentally sound alternatives, as evidenced by their inclusion on the discussion table for the United Nations Global Plastics Treaty. In fact, amid the growing trend to ban the use of single-use plastics, many countries have already adopted plans to promote the use and application of bioplastics in various industries, including packaging, automotive, consumer goods, and agriculture. However, as addressed in the articles related to bioplastics in the Global Plastics Treaty, careful measures are required on both international and national levels to ensure that the introduction of bioplastics genuinely contributes to curbing plastic pollution. In particular, the broader implementation of bioplastics will yield varying outcomes depending on the country’s circumstances and capacities, including national waste management systems. Therefore, country-specific strategies and plans based on solid principles are needed for the smooth transition to bioplastics. This paper provides an overview of bioplastics, including current trends in bioplastics policies and applications, and examines their impact on the environment, waste management systems, and society, drawing implications for their wider implementation in South Korea. At the international level, the analysis highlighted the need to define and standardize bioplastics, including specifying bio-content and characteristics. This involves establishing a common international standard and certification system as well as setting clear guidelines for separation and recycling. For South Korea, it is recommended to limit the application of biobased and biodegradable plastics to protect existing plastic collection and recycling systems. Differentiating applicable items by stages will minimize public inconvenience related to separation. Also, a certification system should be established to prevent greenwashing.
Key Words
Plastics alternatives, Global plastics treaty, Plastic pollution, Sustainability, Waste management systems
Policy Tasks for High Value-Added Industrialization of Deep-Sea Fish By-products 원양산 어류부산물의 고부가가치 산업화를 위한 과제
The purpose of this study is to present policy tasks for the high-value-added industrialization of deep-sea fish by-products. Despite the potential of deep-sea fish by-products to become valuable resources, most are currently used as low-value fishmeal and fish oil, and some are discarded without being recycled. In this paper, the future direction for the industrialization of deep-sea fish by-products is outlined as follows. First, there is an urgent need to revise the ‘Act on Fisheries By-Products’ to include fish by-products. Despite opposition from the Ministry of Environment, recycling fish by-products is a global trend and a crucial task in realizing a circular economy in the fisheries sector. Second, it is necessary to conduct a fact-finding survey on the generation and processing of deep-sea fish by-products and to develop policies for industrialization. We propose that the Ministry of Oceans and Fisheries carry out a research project on the ‘Current status of generation and use of deep-sea fish by-products and industrialization plans’. Third, a foundation must be established to set specific goals for recycling fish by-products and to verify whether these goals have been achieved. Fourth, it is necessary to establish a support organization that leads resource circulation and governance to manage fishery by-products, similar to Iceland's marine cluster. Fifth, standards must be established for the storage and freshness management of fish by-products, including deep-sea fish products. Lastly, the registration of government procurement items should be promoted to stimulate demand for recycled fishery by-products.
Key Words
Circular economy, Fishery by-products, Deep-sea fish, High value-added industrialization
Analysis of Environmental Impact Reduction Effect of Improving Magnesium Hydroxide Extraction Process from Seawater Desalination Brine Using life Cycle Assessment Methodology LCA를 이용한 해수담수화 농축수 내 수산화마그네슘 추출 공정 개선의 환경영향 저감효과 분석
홍성민 Seong Min Hong , 이종효 Jong Hyo Lee , 오상현 Sang Hyun Oh , 황용우 Yong Woo Hwang
Analysis of Environmental Impact Reduction Effect of Improving Magnesium Hydroxide Extraction Process from Seawater Desalination Brine Using life Cycle Assessment Methodology LCA를 이용한 해수담수화 농축수 내 수산화마그네슘 추출 공정 개선의 환경영향 저감효과 분석
홍성민 Seong Min Hong , 이종효 Jong Hyo Lee , 오상현 Sang Hyun Oh , 황용우 Yong Woo Hwang
DOI:10.9786/kswm.2024.41.4.404
Abstract
As the importance of water resource management increases, seawater desalination is emerging as a key technology for supplementing water supplies. However, the concentrated brine produced by seawater desalination plants poses significant environmental risks, including degrading ocean water quality and disrupting marine ecosystems. Under these circumstances, extracting magnesium hydroxide (Mg(OH)2) from concentrated brine has recently gained attention as a promising recycling technology. This study presents a comparative analysis of the life cycle assessment (LCA) related to Mg(OH)2 extraction processes, specifically comparing the use of freshwater versus centrifuge methods. The assessment reveals significant reductions across multiple environmental indicators: Eutrophication potential (EP) showed the most substantial decrease, reduced by 1.24E-01 kg PO43--eq. (▼30.6%). The second most significant reduction was observed in the global warming potential (GWP), which is decreased by 2.31E+02 kg CO2-eq. (▼26.9%). Acidification potential (AP) followed, with an impact reduction of 5.26E-01 kg SO2-eq. (▼20.3%). Other environmental impact categories also saw decreases: abiotic depletion potential (ADP) by 1.23E+00 kg Sb-eq. (▼16.7%), photochemical ozone creation potential (POCP) by 4.29E-02 kg C2H4-eq. (▼8.0%), and ozone depletion potential (ODP) by 4.41E-06 kg CFC-11-eq. (▼5.5%). In addition, after normalization and weighting for relative comparison of the six impact categories, the improved process demonstrates an environmental impact reduction effect of approximately 26.8% compared to the general process. The study quantified and visualized the environmental impacts associated with NaOH and utility use (electricity and water) in the Mg(OH)2 extraction process, highlighting the components that can be reduced to mitigate these impacts. The results suggest that using alternative hydroxides with lower environmental footprints or adopting more energy- and resource-efficient sediment separation technologies could enhance the environmental sustainability of Mg(OH)2 extraction. Consequently, the findings of this research are expected to provide valuable insights for management and policy-making in the seawater desalination and by-product recycling industries.
Key Words
Mg(OH)2 separation and concentration process from seawater desalination brine, Centrifuge, Life Cycle Assessment(LCA), Six environmental impacts, Process improvement
Evaluation of the Application Suitability of Hydrochar Produced from Sewage Sludge and Cow Manure as a Soil Amendment 하수슬러지와 우분뇨를 이용한 hydrochar의 토양개량제 적용성 평가
이선주 Sun-ju Lee , 김태흠 Tae Heum Kim , 이승택 Seungtaek Lee , 정상언 Sang-un Jeong , 이재영 Jai-young Lee
Evaluation of the Application Suitability of Hydrochar Produced from Sewage Sludge and Cow Manure as a Soil Amendment 하수슬러지와 우분뇨를 이용한 hydrochar의 토양개량제 적용성 평가
이선주 Sun-ju Lee , 김태흠 Tae Heum Kim , 이승택 Seungtaek Lee , 정상언 Sang-un Jeong , 이재영 Jai-young Lee
DOI:10.9786/kswm.2024.41.4.417
Abstract
In this study, hydrothermal carbonization (HTC) was employed to recycle organic waste with high moisture content, specifically sewage sludge and cow manure. Hydrochar was produced by mixing sewage sludge and cow manure in a 7:3 ratio and was analyzed to contain 58% ash, 29% volatile matter, and 8% fixed carbon. To evaluate the applicability of the produced hydrochar as a soil conditioner, it was mixed with standard sand at various blending ratios. The mixed soil was then analyzed for moisture content, pH, electrical conductivity (EC), exchangeable cations, cation exchange capacity (CEC), total nitrogen (T-N), and available phosphorus (A-P). The results were categorized as superior, intermediate, lower, or poor based on the general planting base soil evaluation grades from the Ministry of Land, Infrastructure, and Transport (MLIT)'s landscaping design standards. The analysis results revealed that hydrochar was rated as superior in all categories, while standard sand was classified as lower in all categories except for pH and EC. However, the addition of hydrochar demonstrated a notable improvement, particularly in exchangeable cations and CEC, which were rated as intermediate, indicating positive results for nutrient availability and soil fertility for plant growth. This improvement was attributed to the high ash content in hydrochar, which induced a liming effect. Therefore, hydrochar made from sewage sludge and cow manure is considered suitable for use as a soil conditioner. However, it is recommended that long-term observations of soil changes can bec onducted in the future.
