The Use of Sensor-based System to Measure Accurate Low Odorant Concentrations

Odour pollution has become a growing concern due to industrialization and public awareness of the importance of preserving a clean environment. Although odours may not pose immediate health risks at low concentrations, prolonged exposure can lead to various adverse effects on human health and socio-economic conflicts. In response to this concern, Instrumental Odour Monitoring Systems (IOMS) are emerging as a solution for real-time monitoring of odour emissions. The present work shows the performance of sensor-based Kunak AIR Pro instrument for odour monitoring at different sites including a WWTP, a sludge treatment plant and a petrochemical plant by accurately measuring low concentrations of H2S, VOCs and NH3. In the WWTP, the performance of the system to monitor H2S in terms of precision and accuracy was evaluated against a H2S analyser showing a high correlation coefficient of 0.77 and a low MAE of 6.9 ppb. Considering an H2S odour threshold of 8 ppb, the TPR and FPR were calculated to be 0.87 and 0.34. By setting a more conservative alarm threshold (20 ppb), TPR and FPR can be improved to 0.89 and 0.16, respectively. Moreover, by combining the complementary responses of different sensors, such as those for H2S and VOCs, emissions of additional compounds can be inferred, increasing the capabilities of these systems. In a sludge treatment and a petrochemical plant, the deployment of monitoring devices for VOCs, H2S, and NH3 and meteorological data provided valuable insights into the temporal variations and spatial distribution of these compounds within the studied facilities as well as into the potential identification of emission sources. This information is crucial for implementing proactive measures to minimize environmental impact and address potential odour issues demonstrating the importance of sensor-based monitoring systems in providing real-time data for informed decision-making.