Diffusion-Based Continuous Real-Time Monitoring System for Total Volatile Organic Compounds

Abstract

In this study, a total volatile organic compound (TVOC) monitoring system was developed and employed for the continuous and real-time monitoring of TVOCs. Gas chromatography (GC) coupled with thermal desorption (TD) and a commercially available portable VOC detector were simultaneously applied to verify the performance of the developed system. Since the developed system was applicable with and without a pump, the effect of the pump on the monitoring performance was also investigated. Overall, the reliable accuracy and precision of the developed TVOC monitoring system were verified in the TVOC concentration of 50~5000 ppbv. Based on the simultaneous analysis with TD-GC, the TVOC monitoring system showed nearly identical performance to the TD-GC system regardless of the presence of the pump. When compared to the commercially available and portable VOC detector equipped with an internal pump, the maximum delayed response of the TVOC monitoring system was 15 min. In the VOC transport in soil, the breakthrough curve was successfully obtained compared to the case with the TD-GC system. Considering the measurement frequency of the TD-GC system, the TVOC monitoring system as a passive monitoring device can be effectively applied to the subsurface area with the TVOC concentration at or above 50 ppbv.