Monitoring the exhaust air of a compost pile as a process variable with an e-nose

This study aimed at analysing the utilization of an electronic nose (e-nose) to serve as a specific monitoring tool for anaerobic digestion process, especially for detecting organic overload. An array of non specific metal oxide semiconductor gas sensors were used to detect process faults due to organic overload events in twelve 1.8-L anaerobic semi-continuous reactors. Three different load strategies were followed: (1) a cautious organic load (1.3 gVS L -1 day -1 ); (2) an increasing load strategy (1.3-5.3 gVS L -1 day -1 ) and (3) a cautious organic load with load pulses of up to 12 gVS L -1 day -1 . A first monitoring campaign was conducted with three different substrates: sucrose, maize oil and a mix of sucrose/oil during 60 days. The second campaign was run with dry sugar beet pulp for 45 days. Hotelling's T 2 value and upper control limit to a reference set of digesters fed with a cautious OLR (1.3 gVS L -1 day -1 ) was used as indirect state variable of the reactors. Overload situations were identified by the e-nose apparatus with Hotelling's T 2 values at least four times higher in magnitude than the upper control limit of 23.7. These results confirmed that the e-nose technology appeared promising for online detection of process imbalances in the domain of anaerobic digestion.

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“…1) was adapted from the systems described in [22][23][24]. Sensors were selected according to the biogas composition.…”

Section: Monitoring With the E-nosementioning

confidence: 99%

Evaluation of an electronic nose for the early detection of organic overload of anaerobic digesters

Adam

Lemaigre²,

Romain

et al. 2012

Bioprocess Biosyst Eng

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“…Moreover, the composition of the compost exhaust air indicates the aeration status of the process and the quality of the final product (4,5). Previous research identified the probable biomarker gases released by swine mortalities inside biosecure compost systems (6)(7)(8) as dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), and pyrimidine.…”

Section: Introductionmentioning

confidence: 99%

Air Sampling and Analysis Method for Volatile Organic Compounds (VOCs) Related to Field-Scale Mortality Composting Operations

Akdeniz

Kozieł

Ahn

et al. 2009

J. Agric. Food Chem.

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In biosecure composting, animal mortalities are so completely isolated during the degradation process that visual inspection cannot be used to monitor progress or the process status. One novel approach is to monitor the volatile organic compounds (VOCs) released by decaying mortalities and to use them as biomarkers of the process status. A new method was developed to quantitatively analyze potential biomarkers-dimethyl disulfide, dimethyl trisulfide, pyrimidine, acetic acid, propanoic acid, 3-methylbutanoic acid, pentanoic acid, and hexanoic acid-from field-scale biosecure mortality composting units. This method was based on collection of air samples from the inside of biosecure composting units using portable pumps and solid phase microextraction (SPME). Among four SPME fiber coatings, 85 μm CAR/PDMS was shown to extract the greatest amount of target analytes during a 1 h sampling time. The calibration curves had high correlation coefficients, ranging from 96 to 99%. Differences between the theoretical concentrations and those estimated from the calibration curves ranged from 1.47 to 20.96%. Method detection limits of the biomarkers were between 11 pptv and 572 ppbv. The applicability of the prepared calibration curves was tested for air samples drawn from field-scale swine mortality composting test units. Results show that the prepared calibration curves were applicable to the concentration ranges of potential biomaker compounds in a biosecure animal mortality composting unit. KeywordsAir sampling, compost gas, GC-MS, dimethyl disulfide, dimethyl trisulfide, SPME, volatile fatty acids In biosecure composting, animal mortalities are so completely isolated during the degradation process that visual inspection cannot be used to monitor progress or the process status. One novel approach is to monitor the volatile organic compounds (VOCs) released by decaying mortalities and to use them as biomarkers of the process status. A new method was developed to quantitatively analyze potential biomarkers;dimethyl disulfide, dimethyl trisulfide, pyrimidine, acetic acid, propanoic acid, 3-methylbutanoic acid, pentanoic acid, and hexanoic acid;from field-scale biosecure mortality composting units. This method was based on collection of air samples from the inside of biosecure composting units using portable pumps and solid phase microextraction (SPME). Among four SPME fiber coatings, 85 μm CAR/PDMS was shown to extract the greatest amount of target analytes during a 1 h sampling time. The calibration curves had high correlation coefficients, ranging from 96 to 99%. Differences between the theoretical concentrations and those estimated from the calibration curves ranged from 1.47 to 20.96%. Method detection limits of the biomarkers were between 11 pptv and 572 ppbv. The applicability of the prepared calibration curves was tested for air samples drawn from field-scale swine mortality composting test units. Results show that the prepared calibration curves were applicable to the concentration ranges of potential biomaker...

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“…Nicolas et al [9] used PCA to evaluate data from an electronic nose. The correlations between the sensor of an electronic nose and chemical substances were determined by Romain et al [11] using PCA. PCA was applied to observations of a composting process by means of analytical electrofocusing.…”

Section: Pattern Recognition Calibrationmentioning

confidence: 99%

Application of Multivariate Data Analyses in Waste Management

Böhm¹,

Smidt²,

Tintner³

2013

Multivariate Analysis in Management, Engineering and the Sciences

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Monitoring the exhaust air of a compost pile as a process variable with an e-nose

Cited by 34 publications

References 8 publications

Evaluation of an electronic nose for the early detection of organic overload of anaerobic digesters

Evaluation of an electronic nose for the early detection of organic overload of anaerobic digesters

Air Sampling and Analysis Method for Volatile Organic Compounds (VOCs) Related to Field-Scale Mortality Composting Operations

Application of Multivariate Data Analyses in Waste Management

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