Environmental odour monitoring by electronic nose (original) (raw)
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Water research, 2018
Wastewater treatment plants have widely been described as a significant source of odour nuisance, which has led to an increase of neighbourhood complaints. Therefore, to mitigate the negative impact of odours, the detection and analysis of these emissions are required. This paper presents a measurement system based on an electronic nose for quantitative and qualitative odour analysis of samples collected from six different stages on a wastewater plant. Hence, two features vectors were performed in order to represent quantitative trends of the gaseous mixture sampled on the facility. In addition, odour fingerprints and a PCA were computed to discriminate odours from its sources and to detect relationships among the samples. This approach also comprises a dynamic dilution olfactometer. A PLS regression model was performed to predict the odour concentration by the electronic nose in term of odour units per cubic meter. The results show that the developed electronic nose is a promising ...
Springer eBooks, 2009
Artificial olfaction system (the so-called electronic nose) is a very promising tool to monitor the malodour in the field. Usual measurement techniques of odour use human olfaction or conventional analytical techniques. The first category represents the real odour perception but is not applicable to measure continuously bad odours in the field. The second class of techniques gives the mixture composition but not the global information representative of the odour perception. The e-nose has the potentialities to combine "the odour perception" and the "monitoring in the field". However to be able to reach that goal, the signal processing has to be adapted to work in complex environment. The research group in Arlon has more than ten years experience in the measure of environmental malodours in the field. The paper presents the minimal requirements that the group considers as essential for artificial olfaction system to become successful for this application.
Development of an Electronic Nose for Environmental Odour Monitoring
Sensors, 2012
Exhaustive odour impact assessment should involve the evaluation of the impact of odours directly on citizens. For this purpose it might be useful to have an instrument capable of continuously monitoring ambient air quality, detecting the presence of odours and also recognizing their provenance. This paper discusses the laboratory and field tests conducted in order to evaluate the performance of a new electronic nose, specifically developed for monitoring environmental odours. The laboratory tests proved the instrument was able to discriminate between the different pure substances being tested, and to estimate the odour concentrations giving correlation indexes (R 2 ) of 0.99 and errors below 15%. Finally, the experimental monitoring tests conducted in the field, allowed us to verify the effectiveness of this electronic nose for the continuous detection of odours in ambient air, proving its stability to variable atmospheric conditions and its capability to detect odour peaks.
An alternative approach of the e-nose training phase in odour impact assessment
Chemical Engineering Transactions, 2012
Odour emissions are causing serious nuisance for the population, especially in the surrounding of waste water treatment plants (WWTP) and solid waste treatment plants. Extended exposure to odours generate undesirable reactions ranging from emotional stresses such as unease, discomfort, headaches, or depression to physical symptoms. Odour emission characterization is currently discussed in international literature for opportune implementation. Measurement of emissions can be achieved using different methods (analytical, sensorial and/or senso-instrumental) that have different advantages and problems. Among these techniques, there is a growing interest towards the environmental applications of electronic noses. Electronic nose is the only technique that allows continuous monitoring of odours. However, at present there are several limitations affecting the application of electronic nose in the environmental sector. The study investigates the electronic nose potentialities in the environmental sector. Scope of this research activity is to investigate an alternative method to build training data set necessary to distinguish different odour sources generated by solid waste treatment facilities through electronic nose application. The proposed methodology is based on the straightforward application of the electronic nose directly in field with the aim to reduce the time to build the complete data set. Results highlight the great efficiency of the proposed approach to reduce the time to build the complete data set, to maximize the electronic nose capability of operating a qualitative classification of odour sources.
Electronic noses for the qualitative and quantitative determination of environmental odours
2012
For odour impact assessment purposes it may be very useful to dispose of an instrument (electronic nose) capable of both qualifying and quantifying odours in ambient air. For this reason, in the last decade, at the Politecnico di Milano, in collaboration with Sacmi s.c. and Progress S.r.l., specific electronic noses for the continuous monitoring of environmental odours were developed. Since the first instrument developed (EOS 835), during the last years an innovative electronic nose was realized (EOS 507) with the aim of guaranteeing better performances on field. This paper reports the results of laboratory tests performed on different pure compounds, selected among compounds that are typical of environmental odour emissions, proving the capability of the new instrument EOS 507 of discriminating odours and to determine their concentrations up to very low odour concentration values (about 30 ou E /m 3). Moreover, the two instruments (EOS 507 and EOS 835) were used on field, in order to verify their performances with real environmental odours.
2001
The purpose of the paper is to briefly review some researches regarding the adaptation of the electronic nose principle to recognise some malodour sources in the environment, if possible directly in the field, and to monitor the odour intensity continuously. Research aims at improving the portability and the user-friendliness of the instrument, together with testing what kind of signal may be used to monitor the odour. A laboratory-made electronic nose, constituted of an array of tin-oxide sensors, is used in different configurations. The ambient air is either sampled around environmental sources (landfill, urban waste composting facilities,...), or directly transferred into the sensor chamber in the field. Two main options are considered: firstly identifying the source of odour in the background and among interfering odours and, secondly, when the malodour is recognised, trying to monitor it continuously in order, for example, to assess the nuisance or to control an odour abatement...
Performance study of e-nose measurement chamber for environmental odour monitoring
Chemical Engineering Transactions, 2012
Offensive odours from industrial and sanitary environmental engineering plants can cause problems, such as sleep disorders, migraine and loss of appetite, also considering that they address the quality of life. Odour emission characterization is currently discussed in international literature as to determine its most feasible implementation. A method for continuous odour monitoring is based on the use of electronic noses. Electronic nose is an instrument which comprises an array of electronic chemical sensors with partial specificity and an appropriate pattern recognition system, capable of recognizing simple or complex odours. Aim of this work is to numerically analyze the performance of a sensor chamber in order to improve sensor response signals in terms of stability, reproducibility and response time. Comparative results are based on the location of four different diffusers. The numerical analysis was performed by a computational fluid dynamic (CFD) software in order to guarantee that all sensors are exposed to the same chemical sample under the same experimental conditions for the same time, reducing the presence of stagnant or recirculating regions.
2011
Exhaustive odour impact assessment should involve the evaluation of the impact of odours directly on citizens. For this purpose it might be useful to have an instrument capable of continuously monitoring ambient air quality, detecting the presence of odours and also recognizing its provenance. This paper discusses the laboratory and field tests conducted in order to evaluate the performances of a newly developed electronic nose, specific for the monitoring of environmental odours. The laboratory tests proved the instrument to be able to discriminate the different pure substances being tested, and to estimate the odour concentrations giving correlation indexes (R 2 ) of 0.99 and per cent errors below 15%. Finally, the experimental monitoring conducted on field, allowed to verify the effectiveness of this electronic nose for the continuous detection of odours in ambient air, proving its stability to variable atmospheric conditions and its capability to detect odour peaks.
Journal of Cleaner Production, 2016
Odor emissions from waste management plants have long been an environmental and economic issue, but only recently regional authorities in Italy are regulating this sector by imposing control and mitigation of the phenomenon. Electronic noses, initially developed as cheap, easy tools to detect volatiles, may have the required time-resolved coverage of the odor emission phenomenon in a cheap and feasible way with respect to chemical analysis of air. One crucial issue to resolve is to evaluate the discriminant capacity of a sensor array in-field and under working conditions. In this paper the authors have studied the responses of electronic noses of different technologies to odors emitted from a waste management plant, by integrating results obtained with dynamic olfactometry and gas chromatographyemass spectrometry/olfactometry, in the aim to implement a monitoring system and improve cleaner production technologies. Three most impacting odor sources in the waste management plant were detected: biogas, a by-product of mechanical treatment of municipal solid wastes, with low organic fraction and a sludge pressed and dehydrated from treatment of urban wastewater. The most odor impacting source was the sludge and the major responsible of the odor impacts were aromatics (in particular 1,3,5-trimethyl benzene), aliphatic hydrocarbons, terpenes and sulphur volatiles (methyl disulphide, carbon disulphide, dimethyltrisulphide). Ten Metal Oxide Semiconductors and 32 polymer/black carbon (Nano Composite Array) sensors in two electronic noses, were tested for discrimination source capabilities. Results of linear discriminant analysis and cross validation give 86.7% successful recognition for Metal Oxide Semiconductors, 53.3% for Nano Composite Array and 93.3% for a selection of sensors belonging to both technologies chosen according to the selectivity towards the odor active molecules. The containment of odors could also be achieved by spraying a specific product and monitoring the process using selected sensors of the arrays. The results of the in-field work demonstrate strengths and weaknesses of different construction technologies in the e-noses arrays, to characterize and monitor in-site and in real time odor emissions from waste management plants.