Remote monitoring and real-time abatement of odor emitted from sewer using odor sensors, wireless communication technique and microbial deodorant

Abstract

In this study, a new technology was introduced to monitor the odor occurrence situation at the remote site in real time and the technology to reduce sewage odor by using microbial deodorant. Long-term monitoring and full-scale test was carried out to investigate the odor concentration in the combined sewer using the real - time odor monitoring device which consist of 3 odor sensors with the wireless communication technique, and to investigate the effect of the microbial deodorant on the reduction of sewer odor. The odor monitoring device, which was fabricated using metal oxide semiconductor sensors and code division multi access communication technique, was installed at three sites of the gravity-flow type combined sewer (depth 3m and width 5m) in Gangnam, Seoul. Odor monitoring in field was carried out at the interval of 10 minutes for 304 days over the autumn, winter and summer. The measured results were transmitted to Woosong odor research center about 100km away from the site. The measured sensor value was converted to olfactory odor concentration by the co-relation equation of the sensor value and the olfactory odor concentration. As the monitoring results, more than 40,000 sewage odor data were obtained. The average odor concentration of raw sewage in combined sewer was 464 OUk, which was 321 OUk in winter and 412 OUk in autumn and 659 OUk in summer. The commercial microbial deodorant used in this study was the mixture culture of 48 microbial strains, and the microbial deodorant of 1 m3 d-1 to 2 m3 d-1 was mixed with raw sewage at the 1.5 km upstream of the site where odor complaints occurred. As the experimental results, the average odor concentration of sewage mixed with microbial deodorant was 113 OUk, which was 102 OUk in winter and 298 OUk in autumn and 153 OUk in summer. It was estimated that the odor reduction effect of sewer odor by microbial deodorant is about 74%.