This study analyzed the emission characteristics of air pollutants from 97 municipal solid waste incineration (MSWI) facilities in Korea using long-term Tele-Monitoring System (TMS) data collected from 2015 to 2023. This research focused on four major...
This study analyzed the emission characteristics of air pollutants from 97 municipal solid waste incineration (MSWI) facilities in Korea using long-term Tele-Monitoring System (TMS) data collected from 2015 to 2023. This research focused on four major air pollutants — dust, nitrogen oxides (NOx), hydrogen chloride (HCl), and carbon monoxide (CO) — and examined their emission behavior in relation to facility capacity, aging, incineration type, and the effects of emission standard strengthening implemented in 2019 and 2020. The main objective of this study was to empirically identify and quantify how emission factors (kg/ton) of major air pollutants are influenced by facility characteristics and regulatory changes. Statistical analyses, including descriptive statistics, correlation, and regression, were employed to determine the emission variability (expressed as coefficient of variation, CV) and to derive quantitative relationships between capacity increase and emission reduction. The results revealed that dust and NOx emissions showed a clear decreasing trend as facility capacity increased, demonstrating a linear (R² = 0.98) and logarithmic (R² = 0.66–0.70) relationship, respectively. Specifically, dust emissions decreased from 0.014 kg/ton in facilities under 48 tons/day to 0.010 kg/ton in those above 300 tons/day, indicating a reduction of approximately 8 × 10⁻⁶ kg per ton of increased capacity. These results indicate that larger-scale facilities exhibit improved emission control due to advanced dust collection efficiency and stable automated combustion systems. HCl emissions, however, exhibited weak correlation with facility capacity (R² = 0.42), suggesting a dominant influence of waste chlorine content and absorption tower operating conditions rather than facility scale. CO emissions were significantly higher and more variable (CV = 0.939) in small facilities, mainly due to incomplete combustion and operational instability during reactivation or shutdown periods. In terms of incineration type, stoker-type facilities showed the most stable performance, while pyrolysis and melting types achieved lower dust and NOx emissions but slightly higher CO levels due to gasification-phase partial combustion. In the analysis by facility age, older facilities (over 20 years) demonstrated a 31% reduction in dust emissions (0.012 → 0.009 kg/ton) after the emission standard strengthening, attributed to equipment replacement and control upgrades. However, HCl emissions increased slightly in mid-aged facilities (10–15 years), and CO emissions temporarily rose due to maintenance-related instability. The implementation of the 2019–2020 strengthened standards resulted in average reductions of 20–30% for dust and 18–28% for NOx. Regression analysis indicated that a 1% tightening of standards led to emission reductions expressed by y = 0.0201x + 0.8719 (R² = 0.93) for dust and y = 0.7064x + 25.671 (R²=0.98) for NOx, confirming measurable policy effectiveness. However, HCl and CO did not exhibit significant improvement, indicating the need for process optimization beyond regulatory measures. Overall, this study demonstrates that emission reductions are significantly affected by facility capacity, combustion stability, and regulatory enforcement. The findings confirm that the enlargement of incineration capacity enhances environmental efficiency for dust and NOx control, while technological improvements — particularly in absorption tower performance and combustion air control — are required to manage HCl and CO emissions effectively. This study empirically elucidates the emission characteristics of air pollutants and the regulatory effects associated with municipal solid waste incineration facilities by conducting a multivariate analysis that integrally considers facility capacity, aging, incineration technology, and policy variables, based on long-term nationwide monitoring data. In particular, the regression coefficients and reduction factors derived to quantify the effects of emission standard strengthening provide a scientific basis that can be applied to future policy evaluations, emission prediction modeling, and environmental impact assessments. The findings of this study are expected to serve as fundamental reference data for the optimization of incinerator design and operation, the introduction of performance-based regulatory frameworks, and the formulation of integrated management policies for air pollutants and greenhouse gases in municipal solid waste incineration.