Continuous measurement of air pollutant emissions from textile tentering and drying processes using low-cost sensors

In order to monitor the operational status of the waste gas treatment system in a textile tentering and drying plant, two low-cost volatile organic compounds (VOC) sensors i.e. a metal oxide semiconductor sensor (MOS) and a photoionization detector sensor (PID), along with optical particulate matter (PM) sensors, were installed. Based on the measurement data, the stability and reliability of the monitoring system as well as the treatment effectiveness of the waste gas treatment system were assessed. The results showed that the water scrubber exhibited varying removal capacities for waste gases from the tentering and drying processes. While the electrostatic fume collector demonstrated excellent PM retention, it often resulted in increased VOC sensors readings at the discharge outlets. The correlation between VOC sensor readings was relatively strong across both high and low concentration levels, making it feasible to use the more affordable MOS sensors in place of the more expensive PID sensors. Overall, the data from the MOS sensors also provided some indication of PM concentrations. This study demonstrates that continuous monitoring of a waste gas treatment system using low-cost sensors can deliver valuable measurement data and serve as a control parameter for the operational management. This monitoring approach is particularly suitable for continuous monitoring of waste gas treatment systems in small and medium-sized enterprises.