International efforts are being made to reduce environmental pollution caused by microplastics (MPs). Microplastics are released into the environment through sewage treatment sludge, and the use of sludge as a soil improvement agent is increasing rapidly, emphasising the importance of controlling microplastics in sewage treatment facilities. The release of microplastics into the environment is an increasingly significant concern, with sources including sewage treatment sludge. This study focuses on the analysis of microplastics in sewage sludge using optical (Fourier-transform infrared spectroscopy, FTIR) and thermal (Thermo Extraction Desorption–Gas Chromatograph–Mass Spectroscopy, TED-GC-MS) processing-based analytical equipment. The average amount of MPs in the sewage sludge analysed using FTIR was 228.5 microplastics/g of sludge (MPs/g), primarily of the polypropylene type. Approximately 75% of the MPs were 0.1 mm in size or smaller. However, the average amount of MPs in the sewage sludge determined using TED-GC-MS was 95.79 µg-MPs/g. For the systematic management of microplastics, it is important to estimate the amount of microplastics generated by sewage treatment plants. Therefore, a microplastic generation calculation formula was proposed and used to estimate the potential microplastic generation in sewage treatment plants. The total amount of MPs generated from sewage treatment plants in South Korea, calculated using the equation, was approximately 364 ton/yr; we further divided the total amount by administrative regions. The findings of this study can be applied to assess global trends in MP research.

The quantity of waste from end-of-life vehicles is increasing with an increase in the number of scrapped internal combustion engine vehicles owing to international trends such as carbon neutrality and particulate matter reduction. The recycling rate must be ≥95%; however, the average recycling rate remains at approximately 89%. Therefore, the improvement of the recycling of automobile shredder residues (ASR) is gaining attention. In this study, four types of products (interlocking, clay, and lightweight swelled ceramic (LSC) bricks, and asphalt paving aggregate (APA)) were manufactured using ASR melting slag (ASRMS). Environmental performance, quality standards, and technology were evaluated to assess the recyclability of the manufactured bricks. The interlocking brick substituted melting slag for sand and stone powder as an aggregate. As melting slag content increased, absorption decreased and bending strength increased. Clay brick was manufactured by replacing kaolin and feldspar with melting slag that substituted for 20%. The quality of clay bricks mixed with over 15% melting slag was not better than standard. Asphalt paving aggregate was used to investigate the optimum condition of slag content in mixed asphalt; the mixture ratio showed that 61% broken stone of 13 mm, 6% screenings, 10% melting slag, 15% sand and 8% filler was most effective. A lightweight swelled ceramic brick was manufactured by using melting slag, front glass, and so on. Specific gravity and compressive strength ranged from 0.38 to 0.51 and from 339.7 to 373.6 N/cm². ASRMS exhibited an environmental performance suitable for recycling and the manufactured bricks satisfied the quality standards. The recyclability of ASR was also assessed in terms of waste usage, conformance to quality standards, market size, and demand prediction. APA showed the best results followed by interlocking, clay, and LSC bricks.

In recent years, concerns regarding the environmental impact of microplastics (MPs) have led to increased international attention on these pollutants. Although the initial focus was largely directed toward marine environments, land-based pollution sources, including MP release, have been recognized to directly affect marine ecosystems. Therefore, soil-, atmosphere-, groundwater-, and river-based research is ongoing. However, when considering sources of MP, it is necessary to examine the circular system of plastic in terms of raw materials, production, consumption, discharge, and disposal (recycling). Accordingly, the present study proposes a strategy to effectively manage MPs using this circular system. First, the factors influencing MPs in the circular system were identified, and MPs at the system’s final stage, i.e., at the waste treatment facility, were subsequently investigated. Using the concept of MP waste (MPW), strategies were then developed for effective MP management within the circular system. Applying the proposed theoretical strategy to the Korean waste management system revealed that the new policy framework improves the current MP management system. Overall, this study provides fundamental data for establishing new or improved MP management schemes from a waste sector perspective.

In recent years, concerns regarding the environmental impact of microplastics (MPs) have led to increased international attention on these pollutants. Although initial focus was largely directed toward marine environments, land-based pollution sources, including MP release, has been recognized to directly affect marine ecosystems. Therefore, soil-, atmosphere-, groundwater-, and river-based research is ongoing. However, when considering sources of MP, it is necessary to examine the circular system of plastic in terms of raw materials, production, consumption, discharge, and disposal (recycling). Accordingly, the present study proposes a strategy to effectively manage MPs using this circular system. First, the factors influencing MPs in the circular system were identified, and MPs at the system’s final stage, i.e., at the waste treatment facility, were subsequently investigated. Using the concept of MP waste (MPW), strategies were then developed for effective MP management within the circular system. Applying the proposed theoretical strategy to the Korean waste management system revealed that the new policy framework improves the current MP management system. Overall, this study provides fundamental data for establishing new or improved MP management schemes from a waste sector perspective.

Microplastics (MPs) are being widely detected in various ecosystems, including aquatic and terrestrial environments, which highlights the importance of MP management. MPs are released into the marine environment in various ways. Therefore, our study sought to characterize MPs discharged from different waste treatment facilities. This study focused on by-products of recycling facilities for synthetic polymer, synthetic fiber, rubber, and tire waste. The MPs in the samples were quantitatively and qualitatively analyzed using TED-GC-MS and FTIR. The TED-GC-MS analysis results were as follows: Waste of Synthetic Polymer 2.02 μg/g (PP 1.46 μg/g, PE 0.56 μg/g), Waste of Synthetic Fiber 66.75 μg/g (PET 66.75 μg/g), Waste of Rubber N.D., Waste of Tyre 18.71 μg/g (PP 17.79 μg/g, PS 0.74 μg/g). The FTIR analysis results were divided into three sections: 0.02-0.1 mm (Section 1), 0.1-0.5 mm (Section 2), and 0.5-5.0 mm (Section 3). The number of microplastics for each sample was analyzed for WSP 24.01 ea/g (Section 1: 19.11 ea/kg, Section 2: 3.92 ea/ kg, Section 3: 0.98 ea/kg), WSF 501.44 ea/g, (Section 1: 302.40 ea/kg, Section 2: 187.02 ea/kg, Section 3: 12.02 ea/kg), WRB 10,510.01 ea/g (Section 1: 6,320.58 ea/kg, Section 2: 3,661.20 ea/kg, Section 3: 528.23 ea/kg), WTY 311.52 ea/ g (Section 1: 205.53 ea/kg, Section 2: 104.61 ea/kg, Section 3: 1.38 ea/kg). Therefore, a managements plan for waste treatment facilities must be prepared to reduce microplastics in Korea. Our findings provide a basis for the creation of such a plan in the future.