| 1. |
- Murphy, Kathleen, 1972, et al.
(författare)
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Organic matter fluorescence in municipal water recycling schemes: Toward a unified PARAFAC model
- 2011
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 45:7, s. 2909-2916
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 2. |
- Henderson, R.K., et al.
(författare)
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Evaluation of effluent organic matter fouling in ultrafiltration treatment using advanced organic characterisation techniques
- 2011
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Ingår i: Journal of Membrane Science. - : Elsevier BV. - 1873-3123 .- 0376-7388. ; 382:1-2, s. 50-59
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Anceno, A J, et al.
(författare)
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Of Quantum Dots and Microbes : Smart materials for fluorescence based characterization of environmental microflora
- 2013
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Ingår i: Proc. of the Intl. Conf. on Future Trends in Structural, Civil, Environmental and Mechanical Engineering – FTSCEM 2013. - : SEEK Digital Library. ; , s. 61-65
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Konferensbidrag (refereegranskat)abstract
- Manganese doped zinc sulfide (ZnS:Mn2+) quantum dots (QDs) were surface derivatized for use as versatile fluorescent reporters is the study of microorganisms of relevance in environmental bioprocesses. When intracellularly introduced into permeabilized target bacterial cells, mercaptoacetic acid (MAA) or dithiothreitol (DTT) treatedZnS:Mn2+QDs proved to be good visualization enhancers for morphological observations with epifluorescence microscopy. Alternatively, cell surface adhesion of chitosan capped ZnS:Mn2+QDs also led to a similar effect, namely of QD enhanced contrast of target cells from intrinsic background fluorescence. When DTT surface derivatized ZnS:Mn2+QDs were conjugated with oligonucleotide probes and used in fluorescent in situ hybridization (FISH) analysis, specific detection of bacterial strains representative ofsome proteobacterial classes was achieved.
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| 4. |
- Coleman, H. M., et al.
(författare)
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Occurrence of ectoparasiticides in Australian beef cattle feedlot wastes
- 2013
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 174, s. 265-272
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Tidskriftsartikel (refereegranskat)abstract
- A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous analysis of 6 ectoparasiticides - 2 synthetic pyrethroids (deltamethrin, cypermethrin) and 4 macrocyclic lactones (abamectin, doramectin, ivermectin and eprinomectin) in biosolids. The method was used to investigate the occurrence of these ectoparasiticides in beef cattle feedlot wastes in Australia from 5 commercial feedlot operations which employ varying waste management practices. Deltamethrin and cypermethrin were not detected in any of the samples while abamectin, ivermectin, doramectin and eprinomectin were detected in some of the samples with concentrations ranging from 1 to 36 mu g/kg dry weight (d.w.) freeze dried feedlot waste. Levels of macrocyclic lactones detected in the feedlot wastes varied and were dependent on sample type. The effect of seasonal variations and waste management practices were also investigated in this study.
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| 5. |
- Kananen, L, et al.
(författare)
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Self-rated health in individuals with and without disease is associated with multiple biomarkers representing multiple biological domains
- 2021
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1, s. 6139-
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Tidskriftsartikel (refereegranskat)abstract
- Self-rated health (SRH) is one of the most frequently used indicators in health and social research. Its robust association with mortality in very different populations implies that it is a comprehensive measure of health status and may even reflect the condition of the human organism beyond clinical diagnoses. Yet the biological basis of SRH is poorly understood. We used data from three independent European population samples (N approx. 15,000) to investigate the associations of SRH with 150 biomolecules in blood or urine (biomarkers). Altogether 57 biomarkers representing different organ systems were associated with SRH. In almost half of the cases the association was independent of disease and physical functioning. Biomarkers weakened but did not remove the association between SRH and mortality. We propose three potential pathways through which biomarkers may be incorporated into an individual’s subjective health assessment, including (1) their role in clinical diseases; (2) their association with health-related lifestyles; and (3) their potential to stimulate physical sensations through interoceptive mechanisms. Our findings indicate that SRH has a solid biological basis and it is a valid but non-specific indicator of the biological condition of the human organism.
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| 6. |
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| 7. |
- Lindblom, E, et al.
(författare)
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Dynamic modelling of phosphorus in a nutrient-deficient COD removal system
- 2004
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Ingår i: Young Researchers 2004 (Water and Environmental Management Series (WEMS)). - 1843395053 ; , s. 89-99
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Konferensbidrag (refereegranskat)abstract
- n this paper a new model, tailor-made for nutrient deficient aerobic COD removal, is presented. The Activated Sludge Model No. 1 is chosen as a basis for model development. The original model is extended to include (1) phosphorus state variables; (2) phosphorus and nitrogen limited heterotrophic growth; (3) additional 'luxury' uptake of phosphorus and (4) a separate active biomass component to model predation by higher-order organisms, e.g. protozoa. The phosphorus states are included to model phosphorus consumption in biological growth. Nutrient limitations are modelled using Monod functions. The conventional heterotrophic biomass is assumed to be the only source of carbon and nutrients for the higher-order organisms. The model is reduced in the sense that it only regards aerobic conditions and it omits autotrophic organisms. A measurement campaign carried out at the wastewater treatment plant at Hylte pulp and paper mill in Sweden, together with dynamic phosphorus dosage data, is used for model validation and influent fractionation. Dynamic simulations show that the proposed model represents a possible avenue for upgrading activated sludge models to take into account nutrient deficiency and delayed responses due to variable COD:P ratios within active biomass.
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| 8. |
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| 9. |
- Murphy, Kathleen, 1972, et al.
(författare)
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Characterizing odorous emissions using new software for identifying peaks in chemometric models of gas chromatography-mass spectrometry datasets
- 2012
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Ingår i: Chemometrics and Intelligent Laboratory Systems. - : Elsevier BV. - 0169-7439 .- 1873-3239. ; 118, s. 41-50
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Tidskriftsartikel (refereegranskat)abstract
- 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. © 2012 Elsevier B.V.
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| 10. |
- Murphy, Kathleen, 1972, et al.
(författare)
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Non-methane volatile organic compounds predict odor emitted from five tunnel ventilated broiler sheds
- 2014
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 95, s. 423-432
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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