이승희 Seung-whee Rhee

DOI:10.9786/kswm.2023.40.3.193

Abstract

Waste Electrical and Electronic Equipment (WEEE) generation has been increased significantly every year and about 53.6 million tons in 2019 was discarded worldwide but the treatment method for about 83% of them was not known. Moreover, WEEE generation of 74.7 million tons is anticipated in 2030. The first world forum on WEEE was convened in 2006, at the 8th meeting of the Conference of the Parties to the Basel Convention, leading to the Nairobi Declaration on creating innovative solutions for the environmentally sound management of WEEE. In the Basel Convention all WEEE was regarded as hazardous wastes because of its composition of toxic metals and organic chemicals. In this study, the global trends and regulation of WEEE on five continents around the world were examined, including the Basel Convention regulations. There was a clear difference in WEEE management policies between developed countries and developing countries, and this difference is due to the illegal transboundary movement of WEEE from developed countries to developing countries. Even within the European Union, the illegal movement of WEEE from Western Europe to Eastern Europe can be found. Also, the current status of WEEE management in Korea was examined, evaluating advanced measures and policy directions including extended producer responsibility (EPR) system and eco assurance system (Eco- AS) to establish domestic management plan of WEEE. Domestic advancement measures and policy directions to respond to global changes in WEEE management can be established by improving the reliability of domestic WEEE statistics, forming a domestic policy on WEEE circular economy, expanding domestic WEEE infrastructure, and establishing partnership between Korea and foreign countries.

Key Words

WEEE, Global Policy, Management Plan, Transbounday Movement

최형진 Hyeong-jin Choi , 이승희 Seung-whee Rhee

DOI:10.9786/kswm.2023.40.3.207

Abstract

Internationally, concern over waste plastic management is increasing, and the Basel Convention is emerging as the core framework for global waste plastic management. The Basel Convention is carrying out several works, such as the Conference of the Parties (COP), the Plastic Waste Partnership (PWP), and the BRS-Norad project. As a party to the Basel Convention, Korea needs to prepare countermeasures to fulfill its obligations. In order to improve its waste plastic recycling performance, Korea should establish criteria for identifying types of waste plastics and determining their hazardous characteristics. Also, automated technologies based on artificial intelligence (AI) and big data should be developed. To prevent illegal transboundary movement (TBM) of exported and imported plastic waste, the Ministry of Environment in Korea should prepare guidelines for container inspection and cooperate with the Korea Customs Service to develop a TBM monitoring system. Additionally, Korea should conduct a national inventory of and a technical roadmap for plastic waste for achieving a K-circular economy.

Key Words

Plastic waste, Plastic management, Basel Convention, Domestic strategies

최효현 Hyo-hyun Choi , 홍수연 Soo-yeon Hong , 윤철우 Cheol-woo Yoon , 윤영삼 Young-sam Yoon , 전태완 Tae-wan Jeon

DOI:10.9786/kswm.2023.40.3.218

Abstract

This study was conducted to derive a priority management system for organic solvent waste and to diversify analysis methods for waste organic solvents accordingly. First, we compared and reviewed waste organic solvent management items overseas and organic solvent management items by environmental media in Korea. We selected 38 items to be prioritized for management above other waste organic solvents, none of which are managed by the Waste Management Act. In addition, 72 samples were analyzed to review the applicability of the headspace method, and results using GC/FID and GC/MSD were compared and reviewed. For most items, the headspace analysis result value tended to be higher. In this study, we expect that this method(headspace-gas chromatography/mass spectrometry) is more than sufficient to be used as an organic solvent analysis method for the waste process test standard in the future.

Key Words

Organic solvent wastes, Headspace-gas chromatography/mass spectrometer, Flame ionization detector, Volatile characteristics

전호석 Hoseok Jeon , 김성민 Seongmin Kim , 백상호 Sangho Baek

DOI:10.9786/kswm.2023.40.3.228

Abstract

In this study, triboelectrostatic separation was performed to recover nylon, which accounts for more than 70% of waste fishing net. For Nylon, PP, and PE constituting the waste fishing net, the charge polarity and quantity for various charging materials were measured by Faraday Cage for efficient material separation. The ABS, which can polarize Nylon and PP/ PE and has a relatively large range of charge amounts, was identified. Triboelectrostatic separation using ABS pipe line as a tribo-charger was performed, and optimal separation conditions and efficiency were confirmed under various conditions. As a result, at an electrode voltage of 25 kV, air speed of 10.28 m/s, splitter position moved 6 cm from the center towards the negative electrode, and a relative humidity of 30%, the grade and recovery of Nylon were 98.8% and 83.3%, respectively.

Key Words

Waste fishing net, Recycling, Triboelectrostatic separation, Charging property, Separation property

이현주 Hyunju Lee , 이현준 Hyunjoon Lee , 김수경 Sookyung Kim , 배무기 Mooki Bae

DOI:10.9786/kswm.2023.40.3.235

Abstract

Electrowinning technology using a hydrocyclone electrolyzer can recover valuable metals from low-concentration sources, which is impossible in commercial technological processes due to the special structure of the cyclone. In this study, platinum (< 100 ppm) was effectively recovered using a hydrocyclone electrolytic cell, and the reduction behavior of platinum was analyzed using cyclic voltammetry. As a result, it was confirmed that the reduction peak of platinum was observed from around -0.1 to -0.15 V. In the cyclone electrolytic extraction process, the platinum recovery behavior was analyzed under varying electrolytic conditions such as the initial platinum concentration, applied current, and applied voltage. Most notably, as the applied current increased from 2.9 to 4.9 A, the recovery rate of platinum also increased. Ultimately, more than 99.3% of platinum was recovered after about 3 hours in all experiments. These results demonstrate that electrowinning using a hydrocyclone electrolyzer is an effective process with high economic potential for the recovery of PGMs from dilute solutions.

Key Words

Hydrocyclone electrolyzer, Platinum recovery, Cyclic voltammetry

고인철 Inchul Go , 주문솔 Munsol Ju , 조지혜 Ji Hye Jo

DOI:10.9786/kswm.2023.40.3.242

Abstract

The transition to a circular economy is essential for the sustainability of our society and carbon neutrality. Many countries have established goals and strategies for switching to the circular economy, and are diagnosing how various elements of the circular economy are developing over time. In South Korea, the First Basic Plan on Resource Circulation has set four key indicators to check the progress of implementation, but all of them are limited to waste management. Therefore, this study aims to develop indicators to monitor resource efficiency and circularity by expanding the scope to the entire life cycle of products. It is expected to evaluate the status of the transition to the circular economy in Korea and establish a statistical base for achieving mid- and long-term goals.

Key Words

Circular economy, Monitoring, Indicator, Diagnose, Entire life cycle

주문솔 Munsol Ju

DOI:10.9786/kswm.2023.40.3.253

Abstract

This paper aims to make suggestions for improving the domestic response to the Sustainable Development Goals (SDGs) 12.3.1(b) food waste index adopted in 2015. The goal of the food waste index is quantitatively clear: to reduce by half by 2030. But the baseline years are country specific. The definition of food waste in food waste index is the entire food waste including inedible parts, and does not include parts used as animal feed or industrial raw material. In the United Kingdom and Japan, only edible parts, in divergence with the SDGs guidelines, are being targeted for reduction. The United States of America has reduction targets for both the entire food waste and only edible parts, applying different baselines to each. In Korea, since the food waste reduction policy was first implemented in 1992, food waste had decreased by about 47.8% in 2004. Since 2015, while the recycling policy has been strengthened, the reduction performance has been somewhat stagnant. Considering the reduction policy’s time of implementation, it is proposed to set 1992 as a baseline year for entire food waste and have a 50% reduction target by 2030, or to set 2018 as a baseline year for edible foods and have a 50% reduction target by 2030. Regarding animal feed use, we have already met our food waste reduction target. However, since it is no longer easy to expand into feed, reduction measures should be established that emphasize food waste prevention technologies and food donations rather than animal feed. In conclusion, since we have experience in the fields of food waste reduction as well as recycling, we need to contribute to the global issue by sharing our achievements and limitations.

Key Words

Food waste reduction, Sustainable development goals, Food waste index

송민정 Min Jeong Song , 이명종 Myeong Jong Lee , 오세천 Sea Cheon Oh

DOI:10.9786/kswm.2023.40.3.261

Abstract

Incineration is one of the most common waste treatment methods, and various types of incineration methods are currently used. Among them, the stoker incinerator is the most widely used because it can process larger amounts than other types of incinerators, has high technical maturity, and is economically viable. For the safe operation of incineration facilities, non-molded solid refuse fuel (SRF) is often mixed with the waste. However, when non-molded SRF is used in the stoker incinerator, a phenomenon in which the SRF is not uniformly introduced due to the inflow of combustion air occurs. This non-uniform input causes a problem in the operation of the incinerator by forming a local high-temperature combustion region and results in the generation of clinker. To solve these problems, we tried to derive an improvement plan for stoker incinerator facilities that burn SRF using computational flow analysis.

Key Words

Stoker incinerator, Solid Refuse Fuel (SRF), Computational Fluid Dynamics (CFD)

조문환 Mun-hwan Cho , 장용철 Yong-chul Jang

DOI:10.9786/kswm.2023.40.3.273

Abstract

With the COVID-19 pandemic, the response and management of infectious diseases and infectious medical waste have become more important. In this study, we analyzed the definition and classification system of infectious diseases, infectious medical waste levels, the outbreaks of infectious diseases, the generation of infectious medical waste, changes in the share of infectious medical waste, and the impact of infectious medical waste generation due to the outbreak of COVID-19. It was found that infectious medical waste constituted 0.2% of total medical waste in 2010, but it constituted 7.3% in 2020, 16.4% in 2021, and 18.2% as of the end of June 2022. It was estimated that prior to the outbreak of COVID-19, the unit generation of infectious medical waste by the number of infectious disease outbreaks was 13 kg/case, but by 2020, the unit generation rapidly increased to 99 kg/case due to the impact of COVID-19. Based on the experience of “MERS waste management” in 2015, COVID-19-related waste safety management measures were quickly prepared, and COVID- 19 quarantine medical waste protocols were strengthened to ensure same-day discharge, transportation, and incineration. In Korea, more than 90% of medical waste relies on incineration, and infectious medical waste must be incinerated. In 2019, stable incineration of medical waste was difficult as incineration facilities were operating at 119% capacity. In October 2019, the government converted disposable diapers with low infectivity into general waste, which decreased by about 30%, and from 2020, the incineration treatment capacity increased by 20,000 tons per year.

Key Words

Infectious waste, COVID-19, Medical wast, Incineration

이은송 Eun-song Lee , 송금주 Geumju Song , 서용칠 Yong-chil Seo , 백승기 Seungki Back

DOI:10.9786/kswm.2023.40.3.283

Abstract

This study examined the correlation between Hg content in residues and Hg concentration in the leaching extract of waste sludge after thermal treatment. Based on the results, we identified specific Hg compounds which decomposed during the thermal treatment and the conditions which can remove these thermally unstable Hg compounds. Waste sludge contains a large amount of stable Hg compounds after the sequential extraction process. During the thermal treatment, Hg content in the residues gradually decreased as the temperature and residence time increased. In contrast, the Hg concentration in the leaching extract did not decrease below a certain level of Hg content in the residue. This means that Hg compounds (e.g., HgS) that are stable regarding leaching could remain in the residue after thermal treatment, while Hg compounds (e.g., Hg⁰, HgCl₂, and Hg₂Cl₂) that are thermally unstable and unstable with regard to leaching could be removed during thermal treatment. The results show that Hg content can be effectively reduced while retaining Hg compounds with stability in terms of leaching by applying a thermal treatment.

Key Words

Mercury, Waste sludge, Thermal treatment, Content, Leaching

주유진 Yujin Ju , 류도윤 Doyoon Ryu , 김도용 Do-yong Kim , 김대기 Daegi Kim

DOI:10.9786/kswm.2023.40.3.292

Abstract

The fuel potential of biomass waste from South Korean agricultural by-products was assessed in this study by analyzing water removal from different biomass sources. Total of 13 samples were analyzed to investigate the drying characteristics of agricultural by-products and the dependency of their water removal rate and efficiency on temperature and initial water content. At a temperature of 105 ℃, the drying rate was uniform but slow. However, the evaporation rate increased linearly as the drying temperature increased. To quantitatively compare the evaporation rates at different temperatures, the average evaporation rates were compared. The results showed that the evaporation rate linearly increased as the drying temperature increased. For most biomass types in this study, evaporation started at 150℃, but for biomass types that included hulls, such as those from hogsheads and grapes, the evaporation rate rapidly increased at temperatures above 150℃. The temperature of the drying system and the residence time could be optimized depending on the biomass type to streamline operations.

Key Words

Agricultural by-products, Hydrothermal treatment, Solid Refuse Fuel (SRF), Chemical treatment, Fuel property

김홍경 Hongkyoung Kim , 송하균 Hakyun Song , 이가인 Gain Lee , 장용철 Yong-chul Jang , 김병환 Byeonghwan Kim , 권영선 Youngsun Kwon , 이청희 Chonghee Lee , 최경훈 Kyunghoon Choi

DOI:10.9786/kswm.2023.40.3.301

Abstract

Microplastics have significant impacts on marine and terrestrial ecosystems. In this study, the generation and distribution characteristics of microplastics in road dust sediment (RDS) were evaluated by collecting road dust samples from 12 sites in residential areas, roads, and industrial complexes in Daejeon, South Korea. In addition, the amount of microplastics in sediment removed by street sweeping vehicles was examined. Digital microscopy images showed an average of 1,080 microplastic particles/g in road sediment. The highest amount of microplastics was found in dust samples from heavy traffic road areas, which had an average of 1,369 microplastic particles per one gram of sample. Dust samples from industrial complexes had an average of 1,032 microplastic particles per one gram of sample and those from residential areas had an average of 903.3 microplastic particles per one gram of sample. Microscope-based infrared spectroscopy revealedan average of 193 particles (75.4% detection rate) of microplastic consisted of mainly SBR, PP, PE, and PS. SBR which was the most abundant component, was found to be primarily generated by the abrasion of automobile tires. Finally, two kinds of microplastic particles, obtained from manual sampling and collected by street sweeping vehicles were compared. Approximately 2.2-7.6 billion particles were estimated to be sedimented per day in road dust whereas about 8-16.4 billion particles were removed each day via street sweepers. The results of this study may be used as basic data for establishing a management strategy on microplastics in RDS and minimizing the release of microplastics into freshwater environments.

Key Words

Microplastics, SBR (styrene butadiene rubber), RDS (road dust sediments), Street sweeping

Min-woo Kang , Jong-hyuk Jeon , J. Rajesh Kumar , Jin-young Lee

DOI:10.9786/kswm.2023.40.3.311

Abstract

The recovery and extraction of the vanadium and molybdenum from the spent dehydrogenation catalyst in chloride leach liquor was carried out by solvent extraction technique. The 15% of amine based extractants such as Alamine 336, Alamine 308 and Aliquat 336 diluted in 65% ANYSOL-150 (A-150) and modified by 20% octanol used for present investigations. Effect of time, pH, McCabe-Thiele study as well as stripping studies was established. And two title metal ions were analyzed by inductively coupled plasma optical emission spectrometer (ICP-OES) as analytical technique.

Key Words

Recovery, Vanadium, Molybdenum, Spent catalysts