Monitoring of gases produced in landfills is nowadays a major task for environmental safety of the areas in proximity of garbage dumps. We approached the problem via solid-state chemoresistive gas sensors to detect typical complex organic gases produced by landfills, namely carbon sulphur, dimethyl sulphide, xylene, and tricloroethylene. We have prepared semiconducting sensors based on tin-and titaniumoxides thin films. The layers were deposited using either the RGTO technique or reactive physical vapour deposition. The effect of different metal catalysts and additives was also investigated.We present the results obtained with an electronic nose, based on an array of five sensors, for landfill monitoring. We tried specifically to quantify the malodor intensity at different locations in and around a landfill site. The electronic nose data correlate well with that of a panel of trained judges, which is the standard measurement of malodor intensity. We stress the importance of stable and sensitive sensors, such as the metal oxide thin films produced by sputtering, and of multivariate data analysis for extracting knowledge (eg, gaining selectivity) from the data.
Nova Science Publishers Hauppauge NY, USA
1 Jan 2010
Landfill Research Focus