Holistic approach to odour impact assessment on the basis of three waste management plants

Odour pollution is a significant challenge associated with Waste Management Plants (WMPs) and is related to the emissions of diverse odorants from organic waste decomposition processes. Assessing odorous emissions requires a comprehensive approach that combines analytical and sensory methods. This study showcases such a holistic approach to odour impact assessment at three WMPs in Poland. Sensory investigations included field olfactometry and measurements of odour intensity, frequency, and hedonic quality, while gas sensors and a photoionization detector monitored ammonia, hydrogen sulfide, and total Volatile Organic Compounds (tVOCs) in real time. Additionally, an electronic nose (e-nose) demonstrated its effectiveness in continuously monitoring odour intensity and pinpointing critical sources, showing a strong correlation with sensory and analytical data. To enhance the comparability of sensory data with electronic nose readings, an Odour Air Quality Index (OAQI) was developed by aggregating key sensory parameters into a unified scale representing perceived odour impact. This index enabled a structured comparison with e-nose outputs and supported validation of the instrument's reliability for continuous monitoring. The findings reveal significant spatial and seasonal variability in odour emissions, influenced by technological processes, waste composition, and climatic conditions. Among the three facilities, the biological treatment areas were identified as major odour sources. Furthermore, the quarters were problematic odour hot-spots at one of the facilities. Summer measurements exhibited higher emissions due to increased microbial activity, driven by higher temperatures, while winter emissions were notably lower, reflecting the impact of temperature on decomposition rates. The research underscores the importance of combining sensory techniques, gas analysis, and innovative tools such as the e-nose to enhance odour management in WMPs. Recommendations include improving aeration, enclosing odour-intensive processes, and applying advanced methods such as gas chromatography for detailed emission profiling. This study contributes to improving air quality management in WMPs and mitigating odour nuisance for surrounding communities.