This study was initiated to explore the emission characteristics of Reduced Sulfur Compounds (RSCs: hydrogen sulfide, methyl mercaptan, dimethyl sulfide, dimethyl disulfide), ammonia and trimethylamine from a Wastewater Treatment Plant (WWTP) located at Sun-Cheon, Chonlanam-Do in South Korea. The study also evaluates flux profiles of the six selected odorous compounds and their flux rates (µg/m²/min) and compares their emission characteristics. A Dynamic Flux Chamber DFC was used to measure fluxes of pollutants from the treatment plant. Quality control of odor samples using a non-reactive sulfur dioxide gas determined the time taken for DFC concentration to reach equilibrium. The reduced sulfur compounds were analyzed by interfacing gas chromatography with a Pulsed Flame Photometric Detector (PFPD). Air samples were collected in the morning and afternoon on one day during summer (August) and two days in winter (December and January). Their emission rates were determined and it was observed that during summer relatively higher amounts of the selected odorous compounds were emitted compared to winter. Air samples from primary settling basin, aeration basin, and final settling basin were tested and the total amount of selected odorous compounds emitted per wastewater ton was found to be 1344 µg/m³ from the selected treatment processes. It was also observed that, in this study, the dominant odor intensity contribution was caused by dimethyl disulfide (69.1%).

Because of the comprehensiveness and urgency of environmental challenges, every stakeholder needs to be engaged in reducing environmental impacts. The healthcare sector has rarely been studied, despite its intense effects on the environment, particularly through generating various forms of hazardous waste and intensively consuming energy and water. Many healthcare facilities exist in South Korea, and every citizen frequently visits hospitals thanks to the convenient system. To reduce the environmental impacts of the healthcare sector, the South Korean government has implemented various policy measures aimed at promoting environmental management in that sector. This study evaluated the eco-efficiencies of 21 hospitals from 2012 to 2015 using data envelopment assessment (DEA), used the analytical hierarchy process (AHP) to analyze hospital staff members’ answers to a questionnaire asking about the relative importance and performance of individual environmental management tasks, and also identified environmental management tasks that should be prioritized by building an importance-performance analysis (IPA) matrix using those questionnaire responses. This study found that eco-efficiencies have improved during the period, and that mandatory policy measures were more effective than voluntary agreements for improving eco-efficiency. This implies that rigorous reporting and monitoring should be implemented along with any voluntary agreement. In addition, this study found that the top priorities are “establishment of vision and strategy for environmental management” and “organization of task team for environmental management and task assignment”. This shows the necessity of additional policy measures, such as training or consulting to promote the priorities. In addition to policy recommendations for diffusing environmental management in the South Korean healthcare sector, the methodological approach sheds light for researchers interested in environmental management in the healthcare sector because previous studies depended on qualitative approaches, particularly case studies.

In this study, in order to understand accurate calculation of greenhouse gas emissions of urban solid waste incineration facilities, which are major waste incineration facilities, and problems likely to occur at this time, emissions were calculated by classifying calculation methods into 3 types. For the comparison of calculation methods, the waste characteristics ratio, dry substance content by waste characteristics, carbon content in dry substance, and ¹²C content were analyzed; and in particular, CO₂ concentration in incineration gases and ¹²C content were analyzed together. In this study, 3 types of calculation methods were made through the assay value, and by using each calculation method, emissions of urban solid waste incineration facilities were calculated then compared. As a result of comparison, with Calculation Method A, which used the default value as presented in the IPCC guidelines, greenhouse gas emissions were calculated for the urban solid waste incineration facilities A and B at 244.43 ton CO₂/day and 322.09 ton CO₂/day, respectively. Hence, it showed a lot of difference from Calculation Methods B and C, which used the assay value of this study. It is determined that this was because the default value as presented in IPCC, as the world average value, could not reflect the characteristics of urban solid waste incineration facilities. Calculation Method B indicated 163.31 ton CO₂/day and 230.34 ton CO₂/day respectively for the urban solid waste incineration facilities A and B; also, Calculation Method C indicated 151.79 ton CO₂/day and 218.99 ton CO₂/day, respectively. Implications: This study intends to compare greenhouse gas emissions calculated using ¹²C content default value provided by the IPCC (Intergovernmental Panel on Climate Change) with greenhouse gas emissions calculated using ¹²C content and waste assay value that can reflect the characteristics of the target urban solid waste incineration facilities. Also, the concentration and ¹²C content were calculated by directly collecting incineration gases of the target urban solid waste incineration facilities, and greenhouse gas emissions of the target urban solid waste incineration facilities through this survey were compared with greenhouse gas emissions, which used the previously calculated assay value of solid waste.

The world’s aging fleet of nuclear power reactors faces decommissioning. Because decommissioning is implemented through a series of procedures, and this process changes the links between some industries, its economic impact needs to be investigated. This study compared the economic impacts of three nuclear industry sectors—nuclear generation, nuclear power construction, and nuclear decommissioning—using input-output analysis in South Korea, the first Asian country that has declared a nuclear phaseout. The study also traced changes in the structure of the nuclear industry during the Korean nuclear phaseout and the consequent economic impacts. The study found that the implementation of the nuclear phaseout will lead to a decrease in the induced outputs and the value added of nuclear industries in South Korea; however, this would be offset by deploying more renewable energy. In addition, the temporal impacts on individual sectors vary depending on changes in the number of reactors being decommissioned and the expenditure profile of the nuclear decommissioning sector. The findings call for policy measures that support a soft landing for nuclear industry sectors and related stakeholders, timely development of necessary technologies, and transparency in public communication. This study provides a methodological approach and input structure that can be used for studies in other countries.

N₂O, which is emitted mainly from nitrogen decomposition via bacteria, livestock manure, agricultural fertilizer use, fossil fuel combustion and waste incineration, is classified as a substance that causes significant destruction of the ozone layer. The N₂O measurement methods for these emission sources may be divided into chromatography, optical, and electrical current measurements. Chromatography has been widely utilized for analyzing N₂O. However, up until now, few studies have been conducted on N₂O using photoacoustic spectroscopy. Therefore, this study aimed to evaluate performance of photoacoustic spectroscopy in this regard based on laboratory and field test results. The repeatability of photoacoustic spectroscopy was measured at 1.12%, which is lower than the repeatability of 3.0% suggested by the ISO 1564 standard, so, it has shown an excellent repeatability. The detection limit was determined to be 0.025 ppm, and the response time was confirmed to be 3 min and 26 s. The results of comparison between these measurements and GC show that the latter has superior accuracy, but mobility and convenience are superior for PAS. On the contrary, GC has a continuous measurement limitation, but PAS makes it possible to conduct continuous measurements. Therefore, PAS can be extremely useful to confirm the characteristics of N₂O emissions and to quantify their amount.