Sensor-based Wireless Air Quality Monitoring Network (SWAQMN) - A smart tool for urban air quality management

An air quality monitoring network (AQMN) having the ability to provide high spatial resolution real-time information is one of the key tools for developing management strategies for air quality improvement. National Environmental Engineering Research Institute (CSIR-NEERI) has deployed a Sensor-based Wireless Air Quality Monitoring Network (SWAQMN) to monitor real-time particulate matter (PM10 and PM2.5) concentrations in a highly urbanized megacity, Delhi, the capital of India. The sensors are equipped in a device, called Polludrone and located at ten locations covering different land use and source activities in the city. The Polludrone monitored data was compared with another calibrated PM monitor (GRIMM) for PM10. and PM2.5 concentrations and found a similar trend with correlation coefficient (r(2)) values of 0.73 and 0.85, respectively. The hourly average concentrations of PM10. and PM2.5 were found to be 446 and 242 mu g/m(3) by PM monitor, whereas the Polludrone recorded corresponding values as 314 mu g/m 3 and 176 mu g/m(3), respectively. Daily, diurnal and seasonal variability in PM a . and PM2.5 levels are analyzed at 09 locations in Delhi city using SWAQMN. Further, sensor's monitored data were compared with nearest located Continuous Ambient Air Quality Monitoring Stations (CAAQMS) in the form of Air Quality Index (AQI) and found the AQI values are comparable in all the four seasons. The sensor monitored low AQI values as compared to CAAQMS during monsoon and summer seasons. The present analysis suggests that the sensor-based network (low/affordable cost) can be successfully operated to get the real time air quality levels in an urban area.