Potential emission risks of organic compounds from cement kilns

The extensive application of cement kiln industry results in substantial stack gas emissions, posing a potential risk of discharging organic pollutants. Cement industry is not considered as a primary contributor to persistent organic pollutants like polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), owing to its extremely low emission factor. However, knowledge on the previously unrecognized chemicals that may possess higher emission factors from cement industry is lacking. In this study, non-target screening of pollutants from cement industries were conducted using gas chromatography-quadrupole time-of-flight mass spectrometry. Priority pollutants from cement industry were identified. Alkylated polycyclic aromatic hydrocarbons and chlorobenzene were noteworthy pollutants from cement industry. By comparing the toxicity data and semi-quantitative of the pollutants, 9 chemical compounds, including 1-Methylphenanthrene, were identified as priority pollutants. The emission factors of these selected pollutants from cement industries were about 3-6 orders higher than PCDD/Fs, suggesting a potentially high risk of emission. The nationwide emission estimation indicates a significant release of approximately 300 kg of 1-Methylphenanthrene emanating from the cement industry, necessitating heightened attention. The results are helpful for comprehensive risk assessment of organic pollutants from cement industry.