Monitoring of wastewater odours using an electronic nose

The recent availability of commercial electronic nose instruments for odour detection may offer a rapid and relatively simple technique for monitoring wastewater odours. Results have been reported that for sewage odours from a single source a robust relationship can be found between the responses pa tterns of a sensor array (consisting of 12 conducting polymers) and their a ssociated sewage odour concentrations. However, the initial application of this technology in the field of sewage treatment may not be for detecting n uisance odours but for wastewater monitoring and/or process control of a tr eatment works. A comparison between the odour profiles of sewage liquids an d corresponding BOD, GOD, TOC measurements has demonstrated the ability of a non-specific sensor array to detect changes in the organic content of a w astewater sample. Statistical analysis of the sensor response patterns with BOD value (for sewage samples from the inlet works, settlement tanks and t he final effluent outlet) over a B-month period, showed that for longer tim e periods the relationship between these parameters was essentially non-lin ear, but that over shorter time periods a linear relationship was evident. The findings showed that a number of different wastewater quality relations hips could be formulated from the same electronic nose analysis of a sewage liquid. This suggests that the organic content of a wastewater, as well th e potential of a wastewater to produce nuisance odours, could be predicted from a single headspace analysis of a sewage liquid using a sensor array.