Sensors

Gas Sensors : Methane and Carbon dioxide sensors are used to detect the presence of GHG present in and around the kodungaiyur and perungudi dumpyard. Portable optical sensor for methane detection with a sensitivity of ∼1% of the Lower Explosive Level (LEL) for methane (500 ppm) and able to operate in harsh environments with temperature variation between −20 and 50°C. An optimum design has been identified using two detectors with appropriate optical filtering and with temperature stabilisation of the source and detectors. Based on this design, a prototype instrument has been demonstrated with an ultimate sensitivity.

One densely populated area within 5 km distance of Perungudi and Kodungaiyur landfills will be identified as a source of Municipal solid waste generation. Non-spatially varied data like atmospheric gas concentration pressure, temperature, moisture content & temperature of cover soil will be recorded. Ten hotspots on each of the disposal sites will be identified to install the CH4– CO2 sensors. A 2 m x 2 m x 2 m test Cell will be constructed as shown in the fig. 1 to monitor and record the GHG emissions from each of the hotspots (locations where CH4– CO2 emissions are more) at varying depths, on the dump yards on a continuous basis for a year at periodic intervals. A total 100 CH4– CO2 sensors will be installed to collect the GHG emissions.

Constructed Test Cell
Fig.1 Constructed Test Cell

The data recorded by the sensor will be transmitted through wireless networks continuously as messages to a centralized Data centre web server through Open Geospatial Consortium Standard sensor web to report the GHG concentrations at the dump yards. The collected data transmitted to the data station will give an indication and an alarming increase of the GHG emissions let into the atmosphere. The data will definitely help in understanding the magnitude of Methane and Carbon-dioxide emitted which can otherwise be trapped as a source of energy, by developing a Mathematical Model that would relate the quantity of GHG emitted and the amount of waste dumped on each dumpyard.