Non-methane volatile organic compounds predict odor emitted from five tunnel ventilated broiler sheds

Non-methane volatile organic compounds (NMVOCs) emitted from mechanically ventilated poultry sheds in similar stages (32-36d) of broiler production were measured by thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS), then identified using parallel factor analysis (PARAFAC2) and the NIST11 database. Calibration models predicting odor measured by dilution olfactometry from NMVOC concentrations via orthogonal projection to latent structures (O-PLS) made good predictions (Rp2=0.83-0.87, RMSEp=137-175OU) using one to eight NMVOCs with either one or two latent variables representing odor concentration and character, respectively. Similar changes in odorant composition were observed in each sampling campaign, with samples collected early in the day more odorous and more sulfurous than samples collected later in the day. High litter moisture favored sulfur-containing odorants over alcohols, aldehydes and ketones but had little bearing on perceived odor, whereas high bird density favored alcohols, aldehydes and ketones over sulfur-containing odorants. Eight VOCs that were important predictors of odor across all sheds in order of decreasing importance were dimethyl sulfide (DMS), dimethyl trisulfide (DMTS), 2-3 butanedione, 3-methyl-butanal, 1-butanol, 3-methyl-1-butanol, acetoin, and 2-butanone. Four additional NMVOCs also influenced perceived odor although less predictably; these were n-hexane, 2-butanol, dimethyl disulfide (DMDS), and 1-octen-3-ol. All of the odorants are associated with microbial or fungal activity in the litter and manure, except n-hexane, which may originate from hexane-extracted soybean meal in the chicken feed. The organosulfides measured in this study may have arisen from the field sites as well as from the degradation of thiols captured on sorbent tubes during analysis by TD-GC/MS. © 2013 Elsevier Ltd

A chemical sensor array based system for protecting wastewater treatment plants

International audienceno abstrac

Characterizing odorous emissions using new software for identifying peaks in chemometric models of gas chromatography-mass spectrometry datasets

The task of identifying individual compounds within complex gas chromatography - mass spectrometry (GC-MS) chromatograms is made more difficult by interferences between peaks with similar mass spectra eluting at the same time, typically against a background of chemical and electronic noise. Although chemometric techniques like parallel factor analysis and multivariate curve resolution can help to purify spectra and improve correlations with reference compounds, file incompatibilities between GC-MS acquisition software and modeling software prevent the modeled spectra from being easily compared to spectra in reference libraries. In this paper we present an enhancement to OpenChrom, an open-source software for chromatography and mass spectrometry, which implements the automated cross-matching of modeled spectra to NIST08 and NIST11 mass spectral databases. The benefits of this approach are demonstrated using a complex environmental dataset consisting of non-methane volatile organic compound emissions sampled on an Australian poultry farm. \ua9 2012 Elsevier B.V

Enantiospecific fate of ibuprofen, ketoprofen and naproxen in a laboratory-scale membrane bioreactor

The enantiospecific fate of three common pharmaceuticals was monitored in a laboratory-scale membrane bioreactor (MBR). The MBR was operated with a hydraulic retention time of 24 h and a mixed liquor suspended solids concentration of 8.6–10 g/L. Standard solutions of ibuprofen, ketoprofen and naproxen were dosed into the synthetic feed of the MBR. Influent and permeate samples were then collected for enantiospecific analysis. The individual (R)- and (S)-enantiomers of the three pharmaceuticals were derivatised using a chiral derivatizing agent to form pairs of diastereomers, which could then be separated and analysed by gas chromatography–tandem mass spectrometry (GC–MS/MS). Accurate quantitation of individual enantiomers was undertaken by an isotope dilution process. By comparing the total concentration (as the sum of the two enantiomers) in the MBR influent and permeate, ibuprofen, ketoprofen and naproxen concentrations were observed to have been reduced as much as 99%, 43% and 68%, respectively. Furthermore, evidence of enantioselective biodegradation was observed for all three pharmaceuticals. (S)-Ibuprofen was shown to be preferentially degraded compared to (R)-ibuprofen with an average decrease in enantiomeric fraction (EF) from 0.52 to 0.39. In contrast, (R)-ketoprofen was preferentially degraded compared to (S)-ketoprofen with a relatively minor increase in EF from 0.52 to 0.63. The use of a relatively pure enantiomeric solution of (S)-naproxen resulted in a significant change in EF from 0.99 to 0.65. However, this experiment consistently revealed significantly increased concentrations of (R)-naproxen during MBR treatment. It is hypothesised that the source of this (R)-naproxen was the enantiomeric inversion of (S)-naproxen. Such enantiomeric inversion of chiral pharmaceuticals during wastewater treatment processes has not previously been reported

Organic matter fluorescence in municipal water recycling schemes: Toward a unified PARAFAC model

Organic matter (OM) is a ubiquitous constituent of natural waters quantifiable at very low levels using fluorescence spectroscopy. This technique has recognized potential in a range of applications where the ability to monitor water quality in real time is desirable, such as in water treatment systems. This study used PARAFAC to characterize a large (n = 1479) and diverse excitation emission matrix (EEM) data set from six recycled water treatment plants in Australia, for which sources of variability included geography, season, treatment processes, pH and fluorometer settings. Five components were identified independently in four or more plants, none of which were generated during the treatment process nor were typically entirely removed. PARAFAC scores could be obtained from EEMs by simple regression. The results have important implications for online monitoring of OM fluorescence in treatment plants, affecting choices regarding experimental design, instrumentation and the optimal wavelengths for tracking fluorescent organic matter through the treatment process. While the multimodel comparisons provide a compelling demonstration of PARAFAC's ability to distill chemical information from EEMs, deficiencies identified through this process have broad implications for interpreting and reusing (D)OM-PARAFAC models. © 2011 American Chemical Society

Evaluation of effluent organic matter fouling in ultrafiltration treatment using advanced organic characterisation techniques

Membrane fouling remains an operational challenge in the ultrafiltration (UF) membrane treatment of wastewater effluent and research is on-going to improve understanding of the organic character of foulants. Two advanced organic characterisation techniques that have potential to lend insight into membrane fouling are size exclusion chromatography with organic carbon, UV254 and nitrogen detection (LC-OCD) and fluorescence excitation-emission matrix (EEM) spectroscopy. In this study, UF treatment was undertaken for five tertiary wastewater effluents. The total hydraulic resistance was determined as well as that contributed by foulant layers fractionated by rinsing, backwashing and chemically desorbing. Organic characterisation for UF feed samples, permeates and each foulant layer was then performed using LC-OCD and FEEM spectroscopy with the aim of improving understanding of the character of foulants present in effluent organic matter (EfOM) and to determine the potential for the use of FEEM spectroscopy as a foulant indicator in such systems. It was determined that the biopolymer fraction was most significantly reduced on UF treatment, as anticipated due to its high molecular size. This was supported by the observation that the majority of the foulant layer comprised predominantly protein-enriched biopolymers (38-60% of total foulant layer DOC) that could be removed by rinsing. The resistance attributed to rinsing was directly related to the combined DOC concentration associated with proteins and low molecular weight neutral compounds as defined by LC-OCD analysis. Furthermore, tyrosine-like fluorescence intensity (λex/em=250/304nm) of both the rinsing solutions and UF feed samples showed good correlation with associated hydraulic resistance for EfOM originating from domestic wastewater, suggesting that fluorescence has potential to be used as a foulant indicator for these systems. © 2011 Elsevier B.V

Biofiltration of α-pinene vapours using municipal solid waste (MSW) - Pruning residues (P) composts as packing materials

10 pages, 9 figures, 3 tables, 45 references.In this study, a biofiltration system was designed using mature composts of municipal solid waste (MSW) or MSW mixed with pruning residues (MSW-P) as packing materials to treat vapours of α-pinene (a dominant volatile organic compounds (VOC) emitted during the MSW-P co-composting). Monitoring the efficiency of the biofiltration system was carried out using a photoionization analyser, a commercial electronic nose (e-nose) and gas chromatography - mass spectrometry (GC/MS). Using an EBRT of 66. s, removal efficiencies for both kinds of biofilters were greater than 90% removal at different stages of the experiment. The acclimatisation periods were 10 and 25. days for the MSW biofilter and MSW-P biofilter, respectively. Removal efficiency of the system was strongly dependent upon the moisture content of the packing materials. As moisture content in the biofilters fell to below 66% for the MSW and 51% (dry basis) for MSW-P, the removal efficiency decreased to less than 90%. E-nose and GC/MS data indicate a complete degradation of the α-pinene. The e-nose detected a characteristical background emission (odour fingerprint) of each type of biofilter. Results suggest that e-nose's will become a more powerful tool for monitoring VOCs in biofiltration and composting processes in the future.This work was carried out within the project CTM2007-62117/ TECNO, financially supported by the CICYT (Science, technology Inter Ministerial commission, Spanish Government-co-financed FEDER). Cabeza I.O. held a CSIC-JAE PreDoc PhD scholarship funded by the European Social Fund (ESR) and the Spanish Ministry of Economy and Competiveness.Peer Reviewe