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%).

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.

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.

This study developed the NH₃ emission factor for Liquefied Natural Gas (LNG) power facilities in Korea by analyzing the emission characteristics from two LNG power plants using methods such as uncertainty analysis. Also, comparing the differences in NH₃ emission levels between the developed emission factors, which reflect the characteristics in Korea, and the U.S. Environmental Protection Agency (EPA) values currently applied in Korea. The estimation showed that the NH₃ emission factor for the LNG power plants was 0.0054 ton NH₃/10⁶Nm³, which is approximately nine times less than the EPA NH₃ emission factor of 0.051 ton NH₃/10⁶Nm³ for LNG fuels of the industrial energy combustion sector currently applied in national statistics in Korea. The Selective Catalytic Reduction (SCR) emission factor for LNG power plants was 0.0010 ton NH₃/10⁶Nm³, which is considerably lower than the EPA NH₃ emission factor of 0.146 ton NH₃/10⁶Nm³ currently applied in national statistics in Korea for the LNG fuels of the industrial process sector. This indicated the need for developing an emission factor that incorporates the unique characteristics in Korea. The uncertainty range of the LNG stack NH₃ emission factor developed in this study was ±10.91% at a 95% confidence level, while that of the SCR NH₃ emission factor was –10% to +20% at a 95% confidence level, indicating a slightly higher uncertainty range than the LNG stack. At present, quantitative analysis of air pollutants is difficult because numerical values of the uncertainty are not available. However, quantitative analysis might be possible using the methods applied in this study to estimate uncertainty.

In this study, uncertainties related to NH₃ concentration, emission factor, and emission factor estimation in the exhaust gas of the steel sintering furnace using COG (coke oven gas) among the by-product gas generated in steel production was estimated to identify the missing source. By measuring the NH₃ concentration in the exhaust gas of steel sintering furnace using COG, a concentration between 0.02 and 0.12 ppm was found, with an average concentration of 0.06 ppm, confirming the emissions of NH₃. Using this measurement of the NH₃ concentration, an NH₃ emission factor of 0.0061 kg NH₃/ton was derived. The uncertainty of the developed NH₃ emission factor of the sintering furnace using COG was analyzed using a Monte Carlo simulation. Consequently, the uncertainty range of NH₃ emission factor of the sintering furnace using COG was derived to be −11.4% to +12.89% at the 95% confidence level. According to the results of this study, NH₃ emissions occur from the use of COG, yielding values higher than the NH₃ emission factor resulting from the use of LNG(liquefied natural gas) in combustion facilities. It should be recognized that it is a missing emission source and the corresponding emission should be calculated.