CHARACTERISATION OF SEWAGE AND SEWAGE ODOURS USING AN ELECTRONIC NOSE

Tez Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: University of Hertfordshire, Faculty of Engineering, Civil Engineering, Birleşik Krallık

Tez Danışmanı: Dr. Richard Fenner

Tezin Onay Tarihi: 1997

Tezin Dili: İngilizce

Desteklendiği Program: Diğer

Özet:

Sewage treatment works are one of the major sources that cause atmospheric odour pollution. The increase in the number of complaints about odour nuisance is due to the increase in environmental concerns. Unfortunately, the legislation on odour nuisance from sewage treatment works is very limited. In order to determine the boundaries of legal standards, reliable and efficient odour measurement methods need to be defined.

An electronic NOSE is used for the purpose of characterising sewage odours. The work carried out describes the development of an olfactory sensory system which is specifically tuned to odours of sewage origin and which can give an electronic measure of the strength of the combined odour in relation to the way in which a human nose would detect it.

The project has achieved three key results. As a first step, a suitable methodology has been defined for both liquid sewage and sewage odour samples in order to maintain reliable and reproducible experiments with the electronic NOSE. Secondly, the response of the electronic NOSE to quiescent liquid sewage samples has been studied. The findings of this part of the work suggested that the electronic NOSE has the ability to characterise variations between samples of different origin and of different type. In addition to these, linear relationships between the NOSE output and BOD (Biochemical Oxygen Demand) have been formulated for a specific works over a period of a few weeks. The third part of the experimental programme has studied using the electronic NOSE to analyse sewage odours collected in odour bags. The NOSE output of the samples were correlated with corresponding TON (Threshold Odour Number) and H₂S values. Once again, a clear linear relationship was achieved between the NOSE output and TON/H₂S values over low range of concentrations.

This work demonstrated that the electronic NOSE is capable of characterising sewage odours and that it can be used in process control at sewage treatment works for many purposes subject to further investigation and development of the instrument.