Abstract: A system and method for obtaining an estimate of the concentration of an odor in an air sample from data obtained by evaluating the sample with a sensor-array type electronic nose. Principal components analysis is applied to a set of air sample data including sensor-array data obtained from evaluating the air sample with the sensor-array type electronic nose and measurements of the humidity of the air sample and clean reference air used by the electronic nose to obtain a predetermined number of principal components of the air sample data. The principal components obtained from the air sample are used as inputs to a neural network to obtain as output an estimate of the concentration of the odor in the air sample.

Abstract: A hybrid filter system for degrading a sulfur-containing compound having a primary stage sacrificial filter and a secondary stage biofilter is disclosed. This hybrid filter system significantly increases the lifetime of the biofilter providing a cost effective and removal effective biofiltration filter system. The process consists of two filtration stages, a primary stage sacrificial filtration and a secondary stage biofiltration. A small percentage of the sulfur-containing compound is oxidized to elemental sulfur which blocks the pore space of the filter matrix. The primary stage sacrificial filter is used to trap and remove elemental sulfur which is produced when the sulfur-containing compound is passed through the filter. To protect the secondary stage biofilter from premature plugging by precipitated elemental sulfur the primary stage sacrificial filter is used to capture the precipitated elemental sulfur.