Application of material flow analysis for plastic waste management in the Republic of Korea.

The indiscriminate use of plastics and careless management of plastic waste have caused serious environmental challenges globally. The Republic of Korea (ROK) aims to address the issue by reducing plastic waste generation by up to 50%, and increasing recycling rate by up to 70%, by 2030. To determine the status and future directions for plastic waste management in the ROK, the present study undertook two tasks: (i) a material flow analysis of plastic waste material from industrial sectors to assess the current status of plastic waste recycling and treatment, (ii) an analysis of the material flow of plastic waste based on the "Waste Classification Code." According to the findings, 6.202 million metric tons of plastic waste were generated in 2018, out of which 69%, 25%, and 0.5% was recycled, incinerated, and landfilled, respectively. The recycling rate of synthetic resin waste, which accounts for 96% of synthetic waste polymers discharged in the industrial sector, was 69%, which is a very high rate. However, the closed-loop recycling rate was only 33%. Therefore, the system of management of synthetic resin waste discharge without classification of raw materials should be improved to increase the closed-loop recycling rate of synthetic waste polymers. Furthermore, to increase the closed-loop recycling rate, we suggest the subdivision of synthetic resin waste (51-03-01) in plastic waste classification to improve the discharge separation system, which has been mismanaged. Furthermore, we suggest the formulation of a new management strategy for plastic waste, in accordance with those of other hazardous substances, as regulated by the Waste Control Act.

Potential risk of exposure to heavy metals from co-processing of secondary wastes in the Republic of Korea.

The co-processing of secondary wastes during ordinary Portland cement (OPC) can result in high heavy metal concentrations in OPC products. However, earlier studies have not evaluated the concentrations of heavy metals (HMs) in OPC as a function of secondary input materials. Further, the health risk assessment (HRA) model has, thus far, has not been employed to assess the potential health risks associated with secondary raw materials and secondary fuels in OPC. Hence, to address these knowledge gaps, herein, monthly data for six HMs in the input materials and fuels from seven OPC manufacturers in the Republic of Korea were analyzed and modeled. Pb and Cu concentrations were found to be approximately 10-200 and 4-200 times higher than those of the other HMs, respectively. Furthermore, maximum Pb and Cu concentrations were 2-3 and 2-5 times higher than those reported in other countries, respectively. The quantity of input material had a significant influence on the observed patterns, and secondary raw materials, secondary additives, and secondary fuels were also determined to be important. Based on HRA assessment, although the risk levels were within permissible ranges, carcinogenic hazards attributable to Cr and Pb were not negligible. The results can aid in informed decision making and in implementing effective measures for managing risks associated with HMs in the OPC industry, thereby ameliorating threats to human health and environment.

Characterization of wastes from construction and demolition sector.

In Republic of Korea, construction and demolition (C&D) waste accounts for 49.9% of the total waste. In the present work, the mineralogical composition, the concentrations of 11 heavy metals, 19 PAH, and 7 polychlorinated biphenyl (PCB) congeners present in the 6 broad category (9 subcategories) of C&D hazardous waste were discussed along with their leaching characteristics. In concrete/mixed cement waste, the concentrations of As, Cr(6+), Hg, and Zn were in the range of 1.76-7.86, ND-1.63, 0.026-0.047, and 110.90-280.17 mg/kg, respectively. The asphalt waste sample A1 possessed relatively high concentrations of phenanthrene, fluoranthene, pyrene, benz(a)anthracene, benzo(a)pyrene, and indeno(1,2,3-cd)pyrene comparing to the other samples and it contains 0.08-0.1% of coal tar. Hazardous nature of the C&D wastes greatly depends on the source of the collection. Zn concentration was above 1000 mg/kg for road asphalt waste samples A4 and A5. Total PCB concentration were high in the soil waste sample S1 (130 µg/kg) as it was the excavated soil obtained from the premises of an oil station. Leaching of As, Ba, CN(-), and F(-) were observed in most of the C&D waste samples.

Effect analysis on waste recycling by introducing a new policy, "Environmental Assessment of Recycling," for establishment of the ESG management system in the Republic of Korea.

To move away from linear system mining-manufacture-production-disposal, most countries have been trying to establish a circular economy, by reusing waste as resources. Responding to this paradigm change, the Ministry of Environment of Korea amended the Wastes Control Act in the 2010s. To increase the recycling rate in Korea, the environmental assessment of recycling (EAR) has been introduced to improve the Wastes Control Act. The whole process of new recycling technologies can be assessed in terms of environmental or technical aspects by assessment institutes of the EAR. Finally, the governmental research institute can approve of an application case, which proves environmental friendliness, even if the technology is not defined in the current act. Recently, 17 companies have been coassessed and approved to recycle steel codes in waste tires as resources for iron smelting via assessments of the whole process, such as environmental analysis and quality assessment. The EAR has been enforcing recycling materials for six years, and the total profit of the companies that were approved was estimated to be approximately 55 million USD. However, many amendments to the EAR continue to be requested by stakeholders. In this study, the effect of the EAR was evaluated, and additional tasks were found to enhance the EAR. Integr Environ Assess Manag 2024;00:1-13. © 2024 SETAC.

Strategic environmental assessment for effective waste management in Korea: A review of the new policy framework.

This study examines the new policy framework, which includes effective environmental assessment procedure to manage waste in Korea. Concept of this framework pursues the important strategies toward the waste reduction, preservation of landfill area, stabilization and removal of hazardous substance in wastes, and optimal treatment for energy and material recovery from wastes. Therefore, it has begun on three points. First, activating the effective recycling system to reuse wastes will be essential to waste reduction. Second, the utilization of substitute resource can be expected through the optimal transforming the wastes into the recycled product, raw material, thermal energy, etc. Third, the characteristics of waste must be evaluated by strategic environmental assessment. To realize this concept, the strategic environment assessment with reinforcement of hazardous property, categorization of recycling type, and classification of environmental assessment procedure depending on the recycling type was provided. In addition, based on this environment assessment, the new policy framework was built through the established and revised Wastes Control Act by focusing on simple systematic procedure for decision of the possible recycling and strengthening the safety of the wastes to a higher level with promoting recycling activities.

Static and dynamic flow analysis of PBDEs in plastics from used and end-of-life TVs and computer monitors by life cycle in Korea.

This study focused on a quantitative substance flow analysis (SFA) of polybrominated diphenyl ethers (PBDEs) in plastics from obsolete TVs and computer monitors that often contain large amounts of the flame retardants. According to the results of the static SFA study, 1.87 tons and 0.28 tons of PBDEs from newly manufactured TVs and computer monitors were introduced into households in 2011 in Korea, respectively. There were approximately 924 tons and 90.3 tons of PBDEs present in TVs and computer monitors in households during product use, respectively. The results of the dynamic SFA study indicated that in 2017 the amount of PBDEs from TVs and computer monitors in the recycling stage is expected to be 2.63 tons and 0.1 tons, respectively. Large fractions of PBDEs from used TVs are present in recycled plastics, while PBDE-containing computer monitors are exported to Southeast Asian countries. This research indicates that PBDEs were emitted the most from recycled plastic pellet processes upon recycling. Further study may be warranted to focus the flow of PBDEs in recycled plastic products in order to determine the final destination and disposal of these chemicals in the environment.

Emission of polybrominated diphenyl ethers (PBDEs) in use of electric/electronic equipment and recycling of e-waste in Korea.

The emission rates of polybrominated diphenyl ethers (PBDEs) from electric/electronic products during their use and disposal were estimated. E-wastes, including televisions and refrigerators, gathered at recycling centers were also analyzed to estimate their emissions. The average concentrations of PBDEs in TV rear covers produced before and after the year 2000 were 145,027 mg/kg and 14,049 mg/kg, respectively. The PBDEs concentration in TV front covers was lower than the concentration in TV rear covers. The concentration in the components of the refrigerator samples ranged from ND to 445 mg/kg. We estimated the atmospheric emissions of PBDEs based on the concentrations. The annual emissions from TV rear covers produced before 2000 were calculated to be approximately 162.1 kg and after 2000, the annual emissions were 18.7 kg. Refrigerators showed the lowest annual emissions of PBDEs (0.7 kg). The atmospheric concentrations were also measured to calculate emissions generated during the recycling process. The highest concentration was 16.86 ng/m(3) emitted from the TV sets during the dismantling process. The concentrations of PBDEs generated in the plastic processing field ranged from 2.05 to 5.43 ng/m(3) depending on the products, and ambient air in open-air yards showed concentrations in the range of 0.32 to 5.55 ng/m(3). Emission factors for the recycling process were calculated using the observed concentrations. The estimated emissions according to the emission factors ranged from 0.3×10(-1) to 90.3 kg/year for open-air yards and from 0.1×10(-1) to 292.7 kg/year for the dismantling and crushing processes of TV set, depending on the production year.

Hazardous waste characterization among various thermal processes in South Korea: a comparative analysis.

Ministry of Environment, Republic of Korea (South Korea) is in progress of converting its current hazardous waste classification system to harmonize it with the international standard and to set-up the regulatory standards for toxic substances present in the hazardous waste. In the present work, the concentrations along with the trend of 13 heavy metals, F(-), CN(-) and 19 PAH present in the hazardous waste generated among various thermal processes (11 processes) in South Korea were analyzed along with their leaching characteristics. In all thermal processes, the median concentrations of Cu (3.58-209,000 mg/kg), Ni (BDL-1560 mg/kg), Pb (7.22-5132.25mg/kg) and Zn (83.02-31419 mg/kg) were comparatively higher than the other heavy metals. Iron & Steel thermal process showed the highest median value of the heavy metals Cd (14.76 mg/kg), Cr (166.15 mg/kg) and Hg (2.38 mg/kg). Low molecular weight PAH (BDL-37.59 mg/kg) was predominant in sludge & filter cake samples present in most of the thermal processes. Comparatively flue gas dust present in most of the thermal processing units resulted in the higher leaching of the heavy metals.

Ecological risk assessment of chemicals migrated from a recycled plastic product.

OBJECTIVES: Potential environmental risks caused by chemicals that could be released from a recycled plastic product were assessed using a screening risk assessment procedure for chemicals in recycled products. METHODS: Plastic slope protection blocks manufactured from recycled plastics were chosen as model recycled products. Ecological risks caused by four model chemicals -di-(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), cadmium (Cd), and lead (Pb)- were assessed. Two exposure models were built for soil below the block and a hypothetic stream receiving runoff water. Based on the predicted no-effect concentrations for the selected chemicals and exposure scenarios, the allowable leaching rates from and the allowable contents in the recycled plastic blocks were also derived. RESULTS: Environmental risks posed by slope protection blocks were much higher in the soil compartment than in the hypothetic stream. The allowable concentrations in leachate were 1.0×10(-4), 1.2×10(-5), 9.5×10(-3), and 5.3×10(-3) mg/L for DEHP, DINP, Cd, and Pb, respectively. The allowable contents in the recycled products were 5.2×10(-3), 6.0×10(-4), 5.0×10(-1), and 2.7×10(-1) mg/kg for DEHP, DINP, Cd, and Pb, respectively. CONCLUSIONS: A systematic ecological risk assessment approach for slope protection blocks would be useful for regulatory decisions for setting the allowable emission rates of chemical contaminants, although the method needs refinement.