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  • 1. Arshadi, Mehrdad
    et al.
    Sellstedt, Anita
    Unit of Biomass Technology and Chemistry / BTK, Swedish University of Agricultural Sciences, Umea, Sweden.
    Production of energy from biomass2008In: Introduction to chemicals from biomass / [ed] James H. Clark with Fabien E.I. Deswarte, John Wiley & Sons, 2008, p. 143-178Chapter in book (Refereed)
  • 2. Beijer, Kristina
    et al.
    Bjorlenius, Berndt
    Shaik, Siraz
    Lindberg, Richard H.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Brunstrom, Bjorn
    Brandt, Ingvar
    Removal of pharmaceuticals and unspecified contaminants in sewage treatment effluents by activated carbon filtration and ozonation: Evaluation using biomarker responses and chemical analysis2017In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 176, p. 342-351Article in journal (Refereed)
    Abstract [en]

    Traces of active pharmaceutical ingredients (APIs) and other chemicals are demonstrated in effluents from sewage treatment plants (STPs) and they may affect quality of surface water and eventually drinking water. Treatment of effluents with granular activated carbon (GAC) or ozone to improve removal of APIs and other contaminants was evaluated at two Swedish STPs, Kappala and Uppsala (88 and 103 APIs analyzed). Biomarker responses in rainbow trout exposed to regular and additionally treated effluents were determined. GAC and ozone treatment removed 87-95% of the total concentrations of APIs detected. In Kappala, GAC removed 20 and ozonation (7 g O-3/m(3)) 21 of 24 APIs detected in regular effluent. In Uppsala, GAC removed 25 and ozonation (5.4 g O-3/m(3)) 15 of 25 APIs detected in effluent. GAC and ozonation also reduced biomarker responses caused by unidentified pollutants in STP effluent water. Elevated ethoxyresorufin-O-deethylase (EROD) activity in gills was observed in fish exposed to effluent in both STPs. Gene expression analysis carried out in Kappala showed increased concentrations of cytochrome P450 (CYP1A5 and CYP1C3) transcripts in gills and of CYP1As in liver of fish exposed to effluent. In fish exposed to GAC- or ozone-treated effluent water, gill EROD activity and expression of CYP1As and CYP1C3 in gills and liver were generally equal to or below levels in fish held in tap water. The joint application of chemical analysis and sensitive biomarkers proved useful for evaluating contaminant removal in STPs with new technologies.

  • 3.
    Bentzen, Armand
    Umeå University, Faculty of Science and Technology, Umeå Institute of Design.
    Frisk: Showcasing Design Opportunities in a World of Change2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Three global trends are about to greatly influence the world we live in; collaborate consumption, a strong environmental awareness and a third industrial revolution that includes 3D printing, advanced robotics and open source software. This project is addressing these changes in order to evoke new enthusiasm for cars among the general public and again be a creative and positive driving force in our modern society.

    The proposal is illustrated through a halo car for a local car sharing fleet targeted at the Norwegian market. The car seeks to create immediate attention through dynamic design elements as well as long lasting enthusiasm through non-compromised usability.

  • 4. Buss, Wolfram
    et al.
    Jansson, Stina
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Mašek, Ondřej
    Unexplored potential of novel biochar-ash composites for use as organo-mineral fertilizers2019In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 208, p. 960-967Article in journal (Refereed)
    Abstract [en]

    Application of wood ash on forest and agricultural soils can provide nutrients and increase soil pH, however, it changes the soil chemistry rapidly and temporarily, often resulting in reduced plant growth and potassium leaching. Biochar from woody materials are nutrient poor and need nutrient enhancement prior to soil application. In this study, spruce residues were mixed with spruce/pine ash in different ratios (0–50%) to produce biochar-ash composites at 450 °C. The biochar yield (ash-free basis) increased by 80–90% with the addition of 50% ash due to catalytic biochar formation. Consequently, nearly half the amount of wood is needed to produce the same amount of (ash-free) biochar. Mineral release was moderated in the composites compared to pure ash, demonstrated by a lower electric conductivity and % available K content (a factor of 2.5–4.4 lower than in wood ash). Furthermore, the % available chromium content, which is a key potentially toxic element in wood ash, decreased by a factor of 50–160. Soil application of biochar-ash composites decreases the risk of Cr toxicity, salinity stress and leaching of K in soil substantially compared to ash application. Biochar-ash composites are a novel product with vast unexplored potential for use in forestry and agriculture.

  • 5.
    Cutas, Daniela
    et al.
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies.
    Munthe, Christian
    University of Gothenburg, Department of Philosophy, Linguistics and Theory of Science.
    Legal imperialism in the regulation of stem cell research and therapy: the problem of extraterritorial jurisdiction2010In: Contested Cells: Global Perspectives on the Stem Cell Debates / [ed] B. Capps and A. Campbell, Singapore and London: World Scientific and Imperial College Press , 2010Chapter in book (Refereed)
  • 6. Davidsson, A.
    et al.
    Kjerstadius, H.
    Haghighatafshar, S.
    Fick, Jerker
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Olsson, M.
    Wachtmeister, H.
    Eriksson, E.
    Jansen, J. la Cour
    Effect of anaerobic digestion at 35, 55 and 60 degrees C on pharmaceuticals and organic contaminants2014In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 69, no 6, p. 1282-1288Article in journal (Refereed)
    Abstract [en]

    The application of treated sewage sludge on farmland is a suggested method for recycling nutrients and reducing demand for commercial fertilizer. However, sludge needs to be safe from possible contaminants which can cause acute and long-term health and environmental problems. Residual pharmaceuticals and organic contaminants are mentioned as emerging threats since wastewater treatment plants are not designed to degrade these substances. The aim of this study was to screen and evaluate the presence, and reduction, of pharmaceuticals and polycyclic aromatic hydrocarbons (PAHs) during anaerobic digestion of mixed primary and waste-activated sludge at 35, 55 and 60 degrees C and during pasteurization at 70 degrees C. The study showed the difficulty of analysing pharmaceutical compounds in low concentrations in the sludge matrix. No general reduction of these compounds was seen during treatment, but for individual substances some reduction occured. The PAHs were generally not reduced during digestion or pasteurization, but for three substances (indeno[1,2,3-cd]pyreneand dibenzo[a,h] anthracene (analysed together) and benzo [g,h,i] perylene) reduction (up to 60%) during digestion was seen. Digestion at 35 and 55 degrees C resulted in about the same order of reduction of the three individual PAHs, which was higher than for digestion at 60 degrees C.

  • 7. Faleye, A. C.
    et al.
    Adegoke, A. A.
    Ramluckan, K.
    Fick, Jerker
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Bux, F.
    Stenstrom, T. A.
    Concentration and reduction of antibiotic residues in selected wastewater treatment plants and receiving waterbodies in Durban, South Africa2019In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 678, p. 10-20Article in journal (Refereed)
    Abstract [en]

    In the province of KwaZulu-Natal, South Africa the incidence of resistant tuberculosis, upper respiratory tract diseases as well as diarrhoeal and parasitic infections is high. Treatment of these diseases with antibiotics is partly reflected by the excretion of the respective antibiotics and their subsequent occurrence in wastewater. Their quantitative reduction in wastewater treatment reflects their potential environmental as well as human impact, the latter due to the use of the recipient water for domestic purposes and for irrigation. Information of the occurrence and reduction of different classes of antibiotics in wastewater treatment is sparse, especially the particle bound fraction of these. Due to this, analyses of aqueous and particle bound antibiotics in untreated wastewater of four selected wastewater treatment plants (WWTPs) and their receiving water bodies was carried out in Durban, South Africa. The treatment step especially considered was the biological one, represented by activated sludge and trickling filters. The treatment further included secondary clarifiers and final chlorine disinfection. Composite samples were collected during the period February 2017 to May 2017 and analysed with online solid phase extraction - high performance liquid chromatography mass spectrometry (SPE-HPLC-MS). For the 13 assessed antibiotics, the limit of detection (LOD) and the limit of quantification (LOQ) ranged from 0.07 to 0.33 ng L-1 and 0.23 to 1.09 ng L-1 respectively, while the total percentage recovery was in the range of 51 to 111%. The percentage of individual antibiotics bound to the particulate fraction normally lost by sample (influent) filtration, if not analysed in parallel, was in the range of 2.6%-97.3% (n = 32). In this fraction (sludge from centrifuge sample), the concentration of bound antibiotics of all the target antibiotics were detected in the influent of all WWTP in concentration ranges between 1.3 ng L-1 (Azithromycin; AZI) to 81,748 ng(-1) (Ciprofloxacin; CIP). The antibiotics with the highest median concentrations in receiving water bodies of the respective WWTP were: Sulfamethoxazole; SUL (239 ng L-1) WWTP "K", Ciprofloxacin; CIP (708 ng L-1) WWTP "S" and Albendazole; ALB (325 ng L-1 and 683 ng L-1) WWTP "P" and "I" respectively.

    The overall percentage removal efficiency for the four WWTPs ranged from 21% to 100%. The biological treatment steps, activated sludge and trickling filters, were effective in removing antibiotics especially with the trickling filter and the impact of the sedimentation stage after activated sludge treatment. (C) 2019 Elsevier B.V. All rights reserved.

  • 8.
    Fedorova, Ganna
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. University of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Vodnany, Czech Republic.
    Grabic, Roman
    Nyhlen, Jonas
    Järhult, Josef D.
    Söderström, Hanna
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Fate of three anti-influenza drugs during ozonation of wastewater effluents: degradation and formation of transformation products2016In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 150, p. 723-730Article in journal (Refereed)
    Abstract [en]

    Anti-influenza drugs constitute a key component of pandemic preparedness plans against influenza. However, the occurrence of such drugs in water environments, the potential of resistance development in the natural hosts, and the risk for transmission of antiviral resistance to humans call for measures to increase removal in wastewater treatment plants (WWTPs). In this study, removal of three anti-influenza drugs; amantadine (AM), oseltamivir carboxylate (OC) and zanamivir (ZA), and formation/removal of their transformation products during ozonation of wastewater effluents from two Swedish WWTPs in Uppsala and Stockholm were studied. The removal profile of target antivirals and formation/removal of their transformation products were studied by liquid chromatography/high resolution mass spectrometry. 3.5 h of ozone exposure (total dose of ozone 5.95 g) led to complete removal of the three anti-influenza drugs with a degradation in the following order ZA > OC > AM. Two, five and one transformation products were identified and semi-quantified for AM, OC and ZA, respectively. Increasing and later decreasing transformation products concentration followed the decrease in concentration of target compounds. All transformation products detected, except one of AM in wastewater from Stockholm WWTP, were removed at the end of the experiment. The removal efficiency was higher for all studied compounds in wastewater from Uppsala WWTP, which had lower TOC and COD values, less phosphorus, and also higher pH in the water. Ozonation thus offers multiple benefits through its potential to degrade influenza antivirals, hence decrease the risk of environmental resistance development, in addition to degrading other pharmaceuticals and resistant microorganisms.

  • 9.
    Fei, Xiaowen
    et al.
    Key Laboratory of Tropical Crop Biotechnology, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science, Haikou 571101, China.
    Eriksson, Mats
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Yang, Jinghao
    Key Laboratory of Tropical Crop Biotechnology, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science, Haikou 571101, China.
    Deng, Xiaodong
    Key Laboratory of Tropical Crop Biotechnology, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science, Haikou 571101, China.
    An Fe deficiency responsive element with a core sequence of TGGCA regulates the expression of FEA1 in Chlamydomonas reinharditii2009In: Journal of biochemistry, ISSN 1756-2651, Vol. 146, no 2, p. 157-166Article in journal (Refereed)
    Abstract [en]

    Iron is essential to the unicellular green alga Chlamydomonas, but the molecular mechanism for response to iron deficiency remains largely unknown. In previous studies, we have identified FOX1 and ATX1 FEREs (Fe deficiency-responsive elements) as important regulation components of iron response in this organism. Here we present another iron regulated gene FEA1, which promoter was analysed by using a 5'-and 3'-end deletion and a scanning mutagenesis assay. The results reveal that the co-existence of -273/-188 and -118/-49 regions from transcriptional start site of FEA1 were sufficient and necessary for Fe deficiency-induced expression. Further deletion analysis indicates both -273/-253 and -103/-85 regions are essential for inducible expression. The scanning mutagenesis analysis of these regions identifies two cis-acting elements: the FeaFeRE1 at -273/-259 (CTGCGGTGGCAAAGT) and FeaFeRE2 at -106/-85 (CCGCCGCNNNTGGCACCAGCCT). Sequence comparison of FeaFeRE1 and FeaFeRE2 reveals a core sequence of TGGCA, which had been found in our previously reported Fe-deficiency-inducible gene ATX1. Moreover, we show that the promoter region of several genes, including FRE1, IRT1, ISCA, ZRT1, ZRT5, NRAMP2 and COPT1, also contains this core sequence, suggesting that at least two classes FeRE elements exist in Clamydomonas, one in FEA1 and ATX1 and others the second in FOX1, FEA2, MTP4, NRAMP3 and RBOL1.

  • 10. Flach, Carl-Fredrik
    et al.
    Genheden, Maja
    Fick, Jerker
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Larsson, D. G. Joakim
    A comprehensive screening of Escherichia coli isolates from Scandinavia's largest sewage treatment plant indicates no selection for antibiotic resistance2018In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 52, no 19, p. 11419-11428Article in journal (Refereed)
    Abstract [en]

    There is concern that sewage treatment plants (STPs) serve as hotspots for emergence and selection of antibiotic resistant bacteria. However, field studies investigating resistance selection by comparing bacterial populations in influents and effluents have produced variable and sometimes contradictive results. Also, large taxonomic changes between influents and effluents make interpretation of studies measuring relative gene abundances ambiguous. The aim here was to investigate whether within-species selection occurs by conducting a comprehensive screening of Escherichia coli isolated from composite influent and effluent samples collected at Scandinavia's largest STP, accompanied by analyses of antibiotics residues. In total, 4028 isolates, collected on eight occasions during 18 months, were screened for resistance to seven antibiotics. Although differences in proportions of resistant E. coli between influent and effluent samples were detected for a few antibiotics on two occasions, aggregated data over time showed no such differences for any of the investigated antibiotics. Neither was there any enrichment of multiresistant or extended-spectrum beta-lactamase-producing isolates through the treatment process. Despite some antibiotics were detected at or close to concentrations predicted to provide some selective pressure, field observations of resistance profiles in E. coli do not provide support for systematic selection in the investigated STP.

  • 11.
    Forss, Jörgen
    et al.
    Linnéuniversitetet, Institutionen för bygg- och energiteknik (BE).
    Pinhassi, Jarone
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Lindh, Markus V.
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Welander, Ulrika
    Linnéuniversitetet, Institutionen för bygg- och energiteknik (BE).
    Microbial diversity in a continuous system based on rice husks for biodegradation of the azo dyes Reactive Red 2 and Reactive Black 52013In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 130, p. 681-688Article in journal (Refereed)
    Abstract [en]

    In the present study the degradation of two common azo dyes used in dye houses today, Reactive Black 5 and Reactive Red 2 was evaluated in biofilters. In two experiments, bioreactors performed over 80% decolorization at a hydraulic retention time of only 28.4 h with little production of metabolites. Molecular analyses showed a diverse and dynamic bacterial community composition in the bioreactors, including members of the Bacteroidetes, Acinetobacter (Gammaproteobacteria) and Clostridium (Firmicutes) that possess the capacity to reduce azo dyes. Collectively, the results indicate that the development of mixed bacterial communities from natural biomaterials contributes to an efficient and robust degradation performance in bioreactors even at high concentration of dyes.

  • 12. Gros, Meritxell
    et al.
    Blum, Kristin
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Jernstedt, Henrik
    Renman, Gunno
    Rodríguez-Mozaz, Sara
    Haglund, Peter
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Andersson, Patrik
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wiberg, Karin
    Ahrens, Lutz
    Screening and prioritization of micropollutants in wastewaters from on-site sewage treatment facilities2017In: Journal of Hazardous Materials, ISSN 0304-3894, E-ISSN 1873-3336, Vol. 328, p. 37-45Article in journal (Refereed)
    Abstract [en]

    A comprehensive screening of micropollutants was performed in wastewaters from on-site sewage treatment facilities (OSSFs) and urban wastewater treatment plants (WWTPs) in Sweden. A suspect screening approach, using high resolution mass spectrometry, was developed and used in combination with target analysis. With this strategy, a total number of 79 micropollutants were successfully identified, which belong to the groups of per- and polyfluoroalkyl substances (PFASs), pesticides, phosphorus-containing flame retardants (PFRs) and pharmaceuticals and personal care products (PPCPs). Results from this screening indicate that concentrations of micropollutants are similar in influents and effluents of OSSFs and WWTPs, respectively. Removal efficiencies of micropollutants were assessed in the OSSFs and compared with those observed in WWTPs. In general, removal of PFASs and PFRs was higher in package treatment OSSFs, which are based on biological treatments, while removal of PPCPs was more efficient in soil bed OSSFs. A novel comprehensive prioritization strategy was then developed to identify OSSF specific chemicals of environmental relevance. The strategy was based on the compound concentrations in the wastewater, removal efficiency, frequency of detection in OSSFs and on in silico based data for toxicity, persistency and bioaccumulation potential.

  • 13. Holmberg, Anna
    et al.
    Fogel, Jenny
    Albertsson, Eva
    Fick, Jerker
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Brown, Jeffrey N
    Paxéus, Nicklas
    Förlin, Lars
    Johnsson, Jörgen I
    Larsson, D G Joakim
    Does waterborne citalopram affect the aggressive and sexual behaviour of rainbow trout and guppy?2011In: Journal of Hazardous Materials, ISSN 0304-3894, E-ISSN 1873-3336, Vol. 187, no 1-3, p. 596-599Article in journal (Refereed)
    Abstract [en]

    Citalopram is one of several selective serotonin reuptake inhibitors (SSRIs) commonly found in treated sewage effluents. Accordingly, there are concerns about possible adverse effects of SSRIs on aquatic organisms, particularly behavioural effects similar to those associated with SSRI use in humans. Rainbow trout fry and adult male guppies were therefore exposed to waterborne citalopram, ranging from environmentally relevant to high concentrations (1, 10, 100μg/L) for 3-7 days. Under these experimental conditions citalopram does not appear to cause significant effects on aggression in rainbow trout fry or on sexual behaviour in male guppies. This may be explained by a relatively low uptake of citalopram from water to fish.

  • 14. Jiang, Tao
    et al.
    Bravo, Andrea G.
    Skyllberg, Ulf
    Björn, Erik
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wang, Dingyong
    Yan, Haiyu
    Green, Nelson W.
    Influence of dissolved organic matter (DOM) characteristics on dissolved mercury (Hg) species composition in sediment porewater of lakes from southwest China2018In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 146, p. 146-158Article in journal (Refereed)
    Abstract [en]

    The origin and composition of dissolved organic matter (DOM) in porewater of lake sediments is intricate and decisive for fate of pollutants including mercury (Hg). While there are many reports on the relationship between dissolved organic carbon concentration (DOC) and mercury (Hg) concentrations in aquatic systems, there are few in which DOM compositional properties, that may better explain the fate of Hg, have been the focus. In this study, porewaters from sediments of three lakes, Caihai Lake (CH), Hongfeng Lake (HF) and Wujiangdu Lake (WJD), all located in southwest China, were selected to test the hypothesis that DOM optical properties control the fate of Hg in aquatic ecosystems. Porewater DOM was extracted and characterized by UV-Vis absorption and fluorescence spectroscopy. A two end-member (autochthonous and allochthonous DOM) mixing model was used to unveil the origin of DOM in porewaters of the three lakes. Our results show a higher input of terrestrial DOM in the pristine lake CH, as compared to lakes HF and WJD lakes, which were both influenced by urban environments and enriched in autochthonous DOM. While the relationships between the concentrations of DOC and the different chemical forms of Hg forms were quite inconsistent, we found important links between specific DOM components and the fate of Hg in the three lakes. In particular, our results suggest that allochthonous, terrestrial DOM inhibits Hg(II) availability for Hg methylating micro-organisms. In contrast, autochthonous DOM seems to have been stimulated MeHg formation, likely by enhancing the activity of microbial communities. Indeed, DOM biodegradation experiments revealed that differences in the microbial activity could explain the variation in the concentration of MeHg. While relationships between concentrations of DOC and Hg vary among different sites and provide little information about Hg cycling, we conclude that the transport and transformation of Hg (e.g. the methylation process) are more strongly linked to DOM chemical composition and reactivity.

  • 15. Kontturi, V
    et al.
    Hyvärinen, S
    García, A
    Murzin, D Yu
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Peiponen, K-E
    Simultaneous detection of absorption spectrum and refractive index ratio with a spectrophotometer: monitoring contaminants in bioethanol2011In: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 22, no 5, p. 6-Article in journal (Refereed)
    Abstract [en]

    The optical properties of a biofuel resulting from the fungi-treated lignocellulosic biomass in an ethanol matrix were studied. The matrix simulates the case that the bioethanol is contaminated by sugars, water and colour pigments that reduce the quality of the biofuel and compromise the combustion process. It is suggested that by applying a spectrophotometer only, it is possible to obtain valid information, i.e. the spectral features of the contaminants as well as the refractive index ratio of bioethanol. This allows for simultaneous purity and density detection of biomass-derived liquids or liquid biofuels, in comparison to a reference representing an ideal bioethanol (pure ethyl alcohol, ethanol of 99.5% purity (v/v)).

  • 16.
    Konwar, Lakhya Jyoti
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Åbo Akademi.
    Bordoloi, Neonjyoti
    Saikia, Ruprekha
    Chutia, Rahul S.
    Kataki, Rupam
    Sidestreams from bioenergy and biorefinery complexes as a resource for circular bioeconomy2018In: Waste biorefinery: potential and perspectives / [ed] Thallada Bhaskar, Ashok Pandey, S.Venkata Mohan, Duu-Jong Lee, Samir Kumar Khanal, Amsterdam: Elsevier, 2018, 1, p. 85-125Chapter in book (Refereed)
    Abstract [en]

    One of the main drivers for the establishment of biorefineries and the drive toward bioeconomy is the call for sustainability. However, the modern-day biorefinery must embrace on the concept of whole-crop approach with complete feedstock utilization and zero waste, leading to a portfolio of valuable products in which food, feed, fuels, chemicals, and materials are produced. In this chapter, we address upon the prospective of improving the economics and carbon efficiency of existing bioenergy and biorefinery complexes through a circular bioeconomy-based whole-crop utilization. We emphasize hereupon the possibility to coproduce value-added products (e.g., chemicals, materials, or energy) from the various sidestreams or by-products generated from biorefinery operations such as CO2, glycerol, hemicelluloses, lignin, and extractives together with their potential as a raw material or chemical platform for the production of marketable products using available process technologies.

  • 17.
    Kozyatnyk, Ivan
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Haglund, Peter
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Lövgren, Lars
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Gustafsson, A.
    MoRe Research AB, Örnsköldsvik, Sweden.
    Törneman, Niklas
    SWECO, Malmö, Sweden.
    Evaluation of barrier materials for removing pollutants from groundwater rich in natural organic matter2014In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 70, no 1, p. 32-39Article in journal (Refereed)
    Abstract [en]

    Permeable barriers are used for passive remediation of groundwater and can be constructed from a range of materials. The optimal material depends on the types of contaminants and physicochemical parameters present at the site, as well as the hydraulic conductivity, environmental safety, availability, cost and long-term stability of the material itself. The aim of the presented study was to test a number of materials for their ability to remove heavy metals and organic pollutants from groundwater with a high (140 mg L-1) content of natural organic matter (NOM). The following materials were included in the study: sand, peat, fly ash, iron powder, lignin and combinations thereof. Polluted water was fed into glass columns loaded with each sorbent and the contaminant removal efficiency of the material was evaluated through chemical analysis of the percolate. Materials based on fly ash and zero-valent iron were found to be the most effective for heavy metal removal, while fly ash and peat were the most effective for removing aliphatic compounds. Filtration through lignin and peat led to leaching of NOM. Although the leaching decreased over time, it remained high throughout the experiments. The results indicate that remediation of contaminated land at disused industrial sites is a complex task that often requires the use of mixed materials or a minimum of two sequential barriers.

  • 18.
    Kozyatnyk, Ivan
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Lövgren, Lars
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Haglund, Peter
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Multivariate assessment of barriers materials for treatment of complex groundwater rich in dissolved organic matter and organic and inorganic contaminants2017In: Journal of Environmental Chemical Engineering, ISSN 2160-6544, E-ISSN 2213-3437, Vol. 5, no 4, p. 3075-3082Article in journal (Refereed)
    Abstract [en]

    This study focused on the challenges of treating groundwater rich in dissolved organic matter and contains both heavy metals and organic pollutants. Activated carbon, fly ash, lignite, peat, torrefied organic material and zero-valent iron were tested as prospective materials for permeable barriers. Removal of different pollutants was analyzed using coefficients of the Freundlich equation for adsorption isotherms. Principal components analysis was used to visualize similarities and differences in pollutant removal efficiency and sorbent capacity between barrier materials. Fly ash, iron (aerobic conditions) and activated carbon were found to be promising materials for dissolved organic matter removal. Fly ash was the most effective material for metal removal, and fly ash, activated carbon and peat were the most effective materials for removal of organic contaminants. Thus, fly ash shows the most potential for simultaneous removal of metals and organic pollutants. However, it has limited capacity for removing neutral halogenated aromatic compounds. For these, zero-valent iron (aerobic conditions) has greater capacity, probably because of the formation of a porous layer of iron oxyhydroxide. In summary, batch adsorption experiments followed by principal components analysis evaluation of the results are useful tools for selecting suitable materials for treatment of groundwater contaminated with multiple organic and inorganic pollutants.

  • 19.
    Lindmark, Manfred
    Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF). Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Optimization of quality assured dataflow from biosensors: Time series analysis of plankton respiration by oxygen optode2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Data analysis can be a time consuming part of an experimental method, especially when the method is used frequently and large amounts of data are produced each time. In this study, an application software was developed to improve work flow and data management for respiration rate measurements using an optical oxygen sensor. The application was used to analyze data files from the oxygen sensor without the need to manually enter and analyze the data in a spreadsheet application. The software was written in the Python programming language and utilized available scientific computing packages as well as a graphical user interface framework to provide user friendly access to all functions. Any number of files with experimental data were imported into the program and a linear regression analysis was done for each file and viewed to verify the quality of the data. Tables and summarizing graphs were used to display the key information and statistical results. The final results were exported for use in other applications. Data processing that used to take an hour to complete was done with the new application in five to ten minutes and the risk of introducing human errors in the data was simultaneously reduced. User tests indicated that learning the basics of the program was easy. This study shows the usefulness of a bioinformatics approach and the tools provided by Python and its related software to solve problems that arise with managing large volumes of numerical data.

  • 20.
    Lundstedt, Erik Torbjörn
    et al.
    AcureOmics AB.
    Trygg, Johan
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Gabrielsson, Jon Robert
    AcureOmics AB.
    Ekström, Gunilla
    Anamar AB.
    METABOLIC PROFILES2012Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    Abstract: The invention relates to the use of endogenous metabolites to produce a metabolic profile of a disorder or disease in a subject, e.g. an autoimmune disease, in particular rheumatoid arthritis, and the analysis of such metabolic profiles in order to find disturbances in such profiles in a subject which are caused by or correlated with the said diseases or disorders. Such disturbances can be normalised by treatment of the subject with specified compounds, particularly N-(2-chloro-3,4-dimethoxybenzylideneamino)guanidine or an aminoguanidine.

  • 21.
    Melin, Mikael
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Konserveringsmetoder mot korrosion på vattensidan av hetvatten pannor: Preservation methods against corrosion at the waterside of hot water boilers2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Rapporten redovisar en utredning av konserveringsmetoder för vattensidan under stilleståndsperioder av ett värmeverk bestående av fem hetvattenpannor med ett gemensamt ångnät. Syftet var att utvärdera olika metoder för att motverka korrosion då pannorna inte är i drift. Konserveringsmetoderna som utreddes och jämfördes internt var konservering med en kvävgaskudde, ångkudde, torrläggning och en kemisk lösning. Att utreda metoderna innebar att uppskatta dess kostnad ekonomiskt genom att beräkna en årskostnad. För att besvara hur effektivt deras skydd mot korrosion är användes litteraturens referenser och teoretiska samband för att uppskatta syrehalten i matarvattnet. För att kunna göra en realistisk jämförelse mellan metoderna har den avgivna effekten för värmeverkets pannor under driftåret 2016 använts som en grund för beräkningarna. Årskostnaderna från konserveringsmetoderna är från 2016 års driftdata av värmeverket. En kvävgaskudde med en renhet av 99,999 % kan resultera i en syrehalt av 9,6 ppb för matarvattnet och har en total årskostnad av 77 300 SEK. En ångkudde har potentialen att bevara vattnet i princip syrefritt och har en total årskostnad av 809 000 SEK med en extern elpanna för ångproduktion. Att torrlägga pannorna är bara möjligt under vissa perioder av året dock skulle en total årskostnad av eldriften för att hålla pannorna torra motsvara en kostnad av 17 500 SEK. Metoden med en kemisk lösning hade en totalårskostnad av 1 640 000 SEK. Baserat på tillgänglig information och utförda antaganden är slutsatsen att värmeverket ifråga rekommenderas att upphöra med en kemisk konserveringsmetod och övergå till en kvävgaskudde som konserveringsmetod mot korrosion då pannorna inte är i drift.

  • 22.
    Moodie, Lindon W. K.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Department of Chemistry, UiT The Arctic University of Norway, Tromsø, Norway.
    Cervin, Gunnar
    Trepos, Rozenn
    Labriere, Christophe
    Hellio, Claire
    Pavia, Henrik
    Svenson, Johan
    Design and Biological Evaluation of Antifouling Dihydrostilbene Oxime Hybrids2018In: Marine Biotechnology, ISSN 1436-2228, E-ISSN 1436-2236, Vol. 20, no 2, p. 257-267Article in journal (Refereed)
    Abstract [en]

    By combining the recently reported repelling natural dihydrostilbene scaffold with an oxime moiety found in many marine antifoulants, a library of nine antifouling hybrid compounds was developed and biologically evaluated. The prepared compounds were shown to display a low antifouling effect against marine bacteria but a high potency against the attachment and growth of microalgae down to MIC values of 0.01 μg/mL for the most potent hybrid. The mode of action can be characterized as repelling via a reversible non-toxic biostatic mechanism. Barnacle cyprid larval settlement was also inhibited at low μg/mL concentrations with low levels or no toxicity observed. Several of the prepared compounds performed better than many reported antifouling marine natural products. While several of the prepared compounds are highly active as antifoulants, no apparent synergy is observed by incorporating the oxime functionality into the dihydrostilbene scaffold. This observation is discussed in light of recently reported literature data on related marine natural antifoulants and antifouling hybrids as a potentially general strategy for generation of improved antifoulants.

  • 23.
    Olofsson, Martin
    et al.
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Lindehoff, Elin
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Frick, Brage
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Svensson, Fredrik
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Legrand, Catherine
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Baltic Sea microalgae transform cement flue gas into valuable biomass2015In: Algal Research, ISSN 2211-9264, Vol. 11, p. 227-233Article in journal (Refereed)
    Abstract [en]

    We show high feasibility of using cement industrial flue gas as CO2 source for microalgal cultivation. The toxicity of cement flue gas (12-15% CO2) on algal biomass production and composition (lipids, proteins, carbohydrates) was tested using monocultures (Tetraselmis sp., green algae, Skeletonema marinoi, diatom) and natural brackish communities. The performance of a natural microalgal community dominated by spring diatoms was compared to a highly productive diatom monoculture S. marinoi fed with flue gas or air-CO2 mixture. Flue gas was not toxic to any of the microalgae tested. Instead we show high quality of microalgal biomass (lipids 20-30% DW, proteins 20-28% DW, carbohydrates 15-30% DW) and high production when cultivated with flue gas addition compared to CO2-air. Brackish Baltic Sea microalgal communities performed equally or better in terms of biomass quality and production than documented monocultures of diatom and green algae, often used in algal research and development. Hence, we conclude that microalgae should be included in biological solutions to transform waste into renewable resources in coastal waters. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

  • 24. Osundeko, Olumayowa
    et al.
    Ansolia, Preeti
    Gupta, Sanjay Kumar
    Bag, Pushan
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Bajhaiya, Amit K.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Promises and challenges of growing microalgae in wastewater2019In: Water conservation, recycling and reuse: issues and challenges / [ed] Rajeev Pratap Singh, Alan S. Kolok, Shannon L. Bartelt-Hunt, Singapore: Springer, 2019, p. 29-53Chapter in book (Refereed)
    Abstract [en]

    Microalgae have been theoretically described as a sustainable feedstock for biofuel production. However, there are still some concerns and obstacles that need to be overcome in order to translate the theoretical promise into commercial and economic success. These obstacles include a high requirement for nutrients and sustainable water source and the identification of affordable cultivation conditions. It has been suggested that growing microalgae in wastewater can potentially offset some of these obstacles. Microalgae can perform a dual role for remediation of nutrient pollutants and biomass production when grown in wastewater. However, there are huge challenges to overcome before this route can be exploited in an economically and environmentally sustainable manner. In the present chapter, the potentials and challenges of growing microalgae in wastewater and its future implications are discussed in detail.

  • 25. Rhén, Christofer
    et al.
    Öhman, Marcus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Gref, Rolf
    Wästerlund, Iwan
    Effect of raw material composition in woody biomass pellets on combustion characteristics2007In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 31, no 1, p. 66-72Article in journal (Refereed)
    Abstract [en]

    Char yield, char combustion time and char combustion rate of pellets made from different tree parts of Norway spruce and industrially made stem wood pellets of Norway spruce and Scots pine were studied. The pellets were incinerated in a laboratory scale oven at various temperatures, gas flows and oxygen concentrations. It was found that the combustion time for a single pellet mostly depended on the raw material composition and to a minor extent on the density. Pellets made of bark had up to a 50% longer char combustion time compared to that of stem wood pellets, due to differences in char yield. Industrially made stem wood pellets of pine and spruce sawdust were found to have small differences in combustion characteristics. The variations in combustion characteristics of pellets are discussed in relation to composition of raw material.

  • 26.
    Sandström, K. J. Mattias
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational Medicine. Cranfield Biotechnology Centre, Cranfield University, UK; Department of Chemistry, National Institute for Working Life, Umeå, Sweden.
    Newman, Jeffrey
    Cranfield Biotechnology Centre, Cranfield University, UK.
    Sunesson, Anna-Lena
    Department of Chemistry, National Institute for Working Life, Umeå, Sweden.
    Levin, Jan-Olof
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational Medicine. Department of Chemistry, National Institute for Working Life, Umeå, Sweden.
    Turner, Anthony P. F.
    Cranfield Biotechnology Centre, Cranfield University, UK.
    Amperometric biosensor for formic acid in air2000In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 70, no 1–3, p. 182-187Article in journal (Refereed)
    Abstract [en]

    The possibility of developing a simple, inexpensive and specific personal passive “real-time” air sampler incorporating a biosensor for formic acid was investigated. The sensor is based on the enzymatic reaction between formic acid and formate dehydrogenase (FDH) with nicotinamide adenine dinucleotide (NAD+) as a co-factor and Meldola's blue as mediator. An effective way to immobilise the enzyme, co-factor and Meldola's blue on screen-printed, disposable, electrodes was found to be in a mixture of glycerol and phosphate buffer covered with a gas-permeable membrane. Steady-state current was reached after 4–15 min and the limit of detection was calculated to be below 1 mg/m3. However, the response decreased by 50% after storage at −15°C for 1 day.

  • 27.
    Sandström, K. J. Mattias
    et al.
    National Institute for Working Life, Umeå, Sweden.
    Sunesson, Anna-Lena
    National Institute for Working Life, Umeå, Sweden.
    Levin, Jan-Olof
    National Institute for Working Life, Umeå, Sweden.
    Turner, Anthony P. F.
    Cranfield Biotechnology Centre, Cranfield University, UK.
    A gas-phase biosensor for environmental monitoring of formic acid: laboratory and field validation2003In: Journal of Environmental Monitoring, ISSN 1464-0325, E-ISSN 1464-0333, Vol. 5, no 3, p. 477-482Article in journal (Refereed)
    Abstract [en]

    In order to encourage more exposure measurements to be performed, a formic acid gas-phase biosensor has been developed for this purpose. In the present paper, an enzyme based biosensor has been validated with respect to analyte selectivity and on-site use. To ensure that the sampler developed measures the compound of interest the biosensor was exposed to three near structural homologues to formic acid, i.e. acetic acid, methanol and formaldehyde. These vapours were generated with and without formic acid and the only compound that was found to have an effect on the performance of the biosensor, albeit a small one, was acetic acid. The field test was performed in a factory using formic acid-containing glue for glulam products. In parallel to the measurements with the biosensor a well defined reference method was used for sampling and analysing formic acid. It was found that the biosensor worked satisfactorily in this environment when used in a stationary position. It was also shown that the biosensor could determine formic acid vapour concentrations down to 0.03 mg m−3.

  • 28.
    Sandström, K. J. Mattias
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational Medicine. National Institute for Working Life, Department of Chemistry, Umeå, Sweden; Cranfield Biotechnology Centre, Cranfield University, Cranfield, Bedford, UK.
    Turner, Anthony P. F.
    Cranfield Biotechnology Centre, Cranfield University, Cranfield, Bedford, UK.
    Biosensors in air monitoring1999In: Journal of Environmental Monitoring, ISSN 1464-0325, E-ISSN 1464-0333, Vol. 1, no 4, p. 293-298Article, review/survey (Refereed)
  • 29. Singer, Andrew C
    et al.
    Järhult, Josef D
    Grabic, Roman
    Umeå University, Faculty of Science and Technology, Department of Chemistry. University of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Vodnany, Czech Republic.
    Khan, Ghazanfar A
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Lindberg, Richard H
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Fedorova, Ganna
    Umeå University, Faculty of Science and Technology, Department of Chemistry. University of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Vodnany, Czech Republic.
    Fick, Jerker
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Bowes, Michael J
    Olsen, Björn
    Söderström, Hanna
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Intra- and inter-pandemic variations of antiviral, antibiotics and decongestants in wastewater treatment plants and receiving rivers2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 9, p. e108621-Article in journal (Refereed)
    Abstract [en]

    The concentration of eleven antibiotics (trimethoprim, oxytetracycline, ciprofloxacin, azithromycin, cefotaxime, doxycycline, sulfamethoxazole, erythromycin, clarithromycin, ofloxacin, norfloxacin), three decongestants (naphazoline, oxymetazoline, xylometazoline) and the antiviral drug oseltamivir's active metabolite, oseltamivir carboxylate (OC), were measured weekly at 21 locations within the River Thames catchment in England during the month of November 2009, the autumnal peak of the influenza A[H1N1]pdm09 pandemic. The aim was to quantify the pharmaceutical response to the pandemic and compare this to drug use during the late pandemic (March 2010) and the inter-pandemic periods (May 2011). A large and small wastewater treatment plant (WWTP) were sampled in November 2009 to understand the differential fate of the analytes in the two WWTPs prior to their entry in the receiving river and to estimate drug users using a wastewater epidemiology approach. Mean hourly OC concentrations in the small and large WWTP's influent were 208 and 350 ng/L (max, 2070 and 550 ng/L, respectively). Erythromycin was the most concentrated antibiotic measured in Benson and Oxford WWTPs influent (max = 6,870 and 2,930 ng/L, respectively). Napthazoline and oxymetazoline were the most frequently detected and concentrated decongestant in the Benson WWTP influent (1650 and 67 ng/L) and effluent (696 and 307 ng/L), respectively, but were below detection in the Oxford WWTP. OC was found in 73% of November 2009's weekly river samples (max = 193 ng/L), but only in 5% and 0% of the late-and inter-pandemic river samples, respectively. The mean river concentration of each antibiotic during the pandemic largely fell between 17-74 ng/L, with clarithromycin (max = 292 ng/L) and erythromycin (max = 448 ng/L) yielding the highest single measure. In general, the concentration and frequency of detecting antibiotics in the river increased during the pandemic. OC was uniquely well-suited for the wastewater epidemiology approach owing to its nature as a prodrug, recalcitrance and temporally-and spatially-resolved prescription statistics.

  • 30.
    Soudham, Venkata Prabhakar
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Chalmers University of Technology.
    Biochemical conversion of biomass to biofuels: pretreatment–detoxification–hydrolysis–fermentation2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The use of lignocellulosic materials to replace fossil resources for the industrial production of fuels, chemicals, and materials is increasing. The carbohydrate composition of lignocellulose (i.e. cellulose and hemicellulose) is an abundant source of sugars. However, due to the feedstock recalcitrance, rigid and compact structure of plant cell walls, access to polysaccharides is hindered and release of fermentable sugars has become a bottle-neck. Thus, to overcome the recalcitrant barriers, thermochemical pretreatment with an acid catalyst is usually employed for the physical or chemical disruption of plant cell wall. After pretreatment, enzymatic hydrolysis is the preferred option to produce sugars that can be further converted into liquid fuels (e.g. ethanol) via fermentation by microbial biocatalysts. However, during acid pretreatment, several inhibitory compounds namely furfural, 5-hydroxymethyl furfural, phenols, and aliphatic acids are released from the lignocellulose components. The presence of these compounds can greatly effect both enzymatic hydrolysis and microbial fermentation. For instance, when Avicel cellulose and acid treated spruce wood hydrolysate were mixed, 63% decrease in the enzymatic hydrolysis efficiency was observed compared to when Avicel was hydrolyzed in aqueous citrate buffer. In addition, the acid hydrolysates were essentially non-fermentable. Therefore, the associated problems of lignocellulose conversion can be addressed either by using feedstocks that are less recalcitrant or by developing efficient pretreatment techniques that do not cause formation of inhibitory byproducts and simultaneously give high sugar yields. A variety of lignocellulose materials including woody substrates (spruce, pine, and birch), agricultural residues (sugarcane bagasse and reed canary grass), bark (pine bark), and transgenic aspens were evaluated for their saccharification potential. Apparently, woody substrates were more recalcitrant than the rest of the species and bark was essentially amorphous. However, the saccharification efficiency of these substrates varied based on the pretreatment method used. For instance, untreated reed canary grass was more recalcitrant than woody materials whereas the acid treated reed canary grass gave a higher sugar yield (64%) than the woody substrates (max 34%). Genetic modification of plants was beneficial, since under similar pretreatment and enzymatic hydrolysis conditions, up to 28% higher sugar production was achieved from the transgenic plants compare to the wild type. As an alternative to the commonly used acid catalysed pretreatments (prior to enzymatic hydrolysis) lignocellulose materials were treated with four ionic liquid solvents (ILs): two switchable ILs (SILs) -SO2DBUMEASIL and CO2DBUMEASIL, and two other ILs [Amim][HCO2] and [AMMorp][OAc]. viii After enzymatic hydrolysis of IL treated substrates, a maximum amount of glucan to glucose conversion of between 75% and 97% and a maximum total sugar yields of between 71% and 94% were obtained. When using acid pretreatment these values varied between 13-77% for glucan to glucose conversion and 26-83% for total sugar yield. For woody substrates, the hemicellulose recovery (max 92%) was higher for the IL treated substrates than compared to acid treated samples. However, in case of reed canary grass and pine bark the hemicellulose recovery (90% and 88%, respectively) was significantly higher for the acid treated substrates than the IL treated samples. To overcome the inhibitory problems associated with the lignocellulose hydrolysates, three chemical conditioning methods were used 1. detoxification with ferrous sulfate (FeSO4) and hydrogen peroxide (H2O2) 2. application of reducing agents (sulfite, dithionite, or dithiothreitol) and 3. treatment with alkali: Ca(OH)2, NaOH, and NH4OH. The concentrations of inhibitory compounds were significantly lower after treatments with FeSO4 and H2O2 or alkali. Using reducing agents did not cause any decrease in the concentration of inhibitors, but detoxification of spruce acid hydrolysates resulted in up to 54% improvement of the hydrolysis efficiency (in terms of sugar release) compared to untreated samples. On the other hand, application of detoxification procedures to the aqueous buffer resulted in up to 39% decrease in hydrolysis efficiency, thus confirming that the positive effect of detoxification was due to the chemical alteration of inhibitory compounds. In addition, the fermentability of detoxified hydrolysates were investigated using the yeast Saccharomyces cerevisiae. The detoxified hydrolysates were readily fermented to ethanol yielding a maximum ethanol concentration of 8.3 g/l while the undetoxified hydrolysates were basically non-fermentable.

  • 31. Swietlik, Joanna
    et al.
    Laskowski, Tomasz
    Kozyatnyk, Ivan
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Adsorption of Natural Organic Matter onto the Products of Water-Pipe Corrosion2015In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 226, no 7, article id 225Article in journal (Refereed)
    Abstract [en]

    Natural organic matter (NOM) interaction with corrosion sediments is important because it can adversely affect the behaviour of many organic and inorganic pollutants in drinking water distribution systems. NOM accumulation onto corrosion sediments can cause serious problems for water supply, such as bacteria regrowth and deterioration of water quality. Corrosion sediments have different structures from the well-known iron oxides. The interaction among corrosion sediments and water organic matter can also differ. The main goal of this work was to understand the adsorption mechanism of the processes of NOM interaction with corrosion sediments. Fulvic acid (FA) isotherms on corrosion sediments in logarithmic coordinates of the Freundlich equation have different segments with different slopes, representing the non-adsorbed and adsorbed conditional component of the FA. The formation of structures with a molecular weight higher than the initial FA was observed. FA adsorption on corrosion sediments depends on time. Almost 60-70 % of the FA was removed during the first 10 min of contact. Such rapid adsorption indicates that FA was accumulated onto corrosion sediments mainly due to physical-chemical interaction. The pseudo-second-order kinetics model was demonstrated to better describe the adsorption of FA onto corrosion sediments than the pseudo-first-order model. External mass transfer is the limiting stage of the process of FA adsorption onto corrosion sediments. This knowledge is useful for understanding of corrosion processes and biological regrowth in water supply pipes and thus further decrease of drinking water quality.

  • 32. Wang, Huijiao
    et al.
    Mustafa, Majid
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Yu, Gang
    Östman, Marcus
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Cheng, Yi
    Wang, Yujue
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Oxidation of emerging biocides and antibiotics in wastewater by ozonation and the electro-peroxone process2019In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 235, p. 575-585Article in journal (Refereed)
    Abstract [en]

    This study investigated the abatement of a number of antimicrobials frequently detected in municipal wastewater by conventional ozonation and a recently developed ozone-based advanced oxidation process, the electro-peroxone (E-peroxone) process. A synthetic water and a real secondary wastewater effluent were spiked with fourteen antimicrobials, including antibiotics and biocides, and then treated by the two processes. The results show that most of the antibiotics investigated (e.g., ofloxacin, trimethoprim, norfloxacin, and ciprofloxacin) readily react with ozone (O3) and could therefore be efficiently eliminated from the water matrices by direct O3 oxidation during both processes. In contrast, most of the biocides tested in this study (e.g., clotrimazole, pentamidine, bixafen, propiconazole, and fluconazole) were only moderately reactive, or non-reactive, with O3. Therefore, these biocides were removed at considerably lower rate than the antibiotics during the two ozone-based processes, with hydroxyl radical (OH) oxidation playing an important role in their abatement mechanisms. When compared with conventional ozonation, the E-peroxone process is defined by the in situ electrogeneration of hydrogen peroxide, which considerably enhances the transformation of O3 to OH. As a result, the E-peroxone process significantly accelerated the abatement of biocides and required a considerably shorter treatment time to eliminate all of the tested compounds from the water matrices than conventional ozonation. In addition, the E-peroxone process enhanced the contributions of OH fractions to the abatement of moderately ozone reactive benzotriazoles. These results demonstrate that the E-peroxone process holds promise as an effective tertiary treatment option for enhancing the abatement of ozone-resistant antimicrobials in wastewater.

  • 33. Zhang, W.
    et al.
    Blum, Kristin M.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Gros, M.
    Ahrens, L.
    Jernstedt, H.
    Wiberg, K.
    Andersson, P. L.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Björlenius, B.
    Renman, G.
    Removal of micropollutants and nutrients in household wastewater using organic and inorganic sorbents2018In: Desalination and Water Treatment, ISSN 1944-3994, E-ISSN 1944-3986, Vol. 120, p. 88-108Article in journal (Refereed)
    Abstract [en]

    The efficiency of five organic and five inorganic sorbents in removing 19 organic micropollutants (MPs), phosphorus, nitrogen, and dissolved organic carbon (DOC) was tested in a two-week column experiment using household wastewater spiked with pharmaceuticals (n = 6), biocides/pesticides (n = 4), organophosphates (n = 3), a fragrance, a UV-stablizer, a food additive, a rubber additive, a plasticizer and a surfactant. Two types of granular activated carbon (GAC), two types of lignite, a pine bark product, and five mineral-based sorbents were tested. All the organic sorbents except pine bark achieved better removal efficiencies of DOC (on average, 70 +/- 27%) and MPs (93 +/- 11%) than the inorganic materials (DOC: 44 +/- 7% and MPs: 66 +/- 38%). However, the organic sorbents (i.e. GAC and xyloid lignite) removed less phosphorus (46 +/- 18%), while sorbents with a high calcium or iron content (i.e. Polonite (R) and lignite) generally removed phosphorus more efficiently (93 +/- 3%). Ammonium- nitrogen was well removed by sorbents with a pH between 7 and 9, with an average removal of 87%, whereas lignite (pH 4) showed the lowest removal efficiency (50%). Some MPs were well removed by all sorbents (>= 97%) including biocides (hexachlorobenzene, triclosan and terbutryn), organophosphates (tributylphosphate, tris-(1,3-dichloro-2-propyl) phosphate and triphenylphosphate) and one fragrance (galaxolide). The pesticide 2,6-dichlorobenzamide and the pharmaceutical diclofenac were poorly removed by the pine bark and inorganic sorbents (on average, 4%), while organic sorbents achieved high removal of these chemicals (87%).

  • 34.
    Åberg, Jan
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Wallin, Marcus B.
    Evaluating a fast headspace method for measuring DIC and subsequent calculation of pCO(2) in freshwater systems2014In: INLAND WATERS, ISSN 2044-2041, E-ISSN 2044-205X, Vol. 4, no 2, p. 157-166Article in journal (Refereed)
    Abstract [en]

    A variety of different sampling and analysis methods are found in the literature for determining carbon dioxide (CO2) in freshwaters, methods that rarely have been evaluated or compared. Here we present an evaluation of an acidified headspace method (AHS) in which the dissolved inorganic carbon (DIC) is measured from an acidified sample and the partial pressure (pCO(2)) is calculated from DIC using pH and water temperature. We include information on practical sampling, accuracy, and precision of the DIC/pCO(2) determination and a storage test of samples. The pCO(2) determined from the AHS method is compared to that obtained from the more widely used direct headspace method (DHS) in which CO2 is equilibrated between the water and gas phases at ambient pH. The method was tested under both controlled laboratory conditions as well as wintertime field sampling. The accuracy of the DIC detection was on average 99% based on prepared standard solutions. The pCO(2) determination in lab, using the DHS method as a reference, showed no significant difference, although the discrepancy between the methods was larger in samples with <1000 mu atm. The precision of the pCO(2) determination was on average +/- 4.3%, which was slightly better than the DHS method (+/- 6.7%). In the field, the AHS method determined on average 10% higher pCO(2) than the DHS method, which was explained by the extreme winter conditions (below -20 degrees C) at sampling that affected the sampling procedure of the DHS method. Although samples were acidified to pH 2, respiration processes were still occurring (at a low rate), and we recommend that analyses are conducted within 3 days from sampling. The AHS method was found to be a robust method to determine DIC and pCO(2) in acidic to pH-neutral freshwater systems. The simple and quick sampling procedure makes the method suitable for time-limited sampling campaigns and sampling in cold climate.

  • 35.
    Öhman, Marcus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Nordin, Anders
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Hedman, H
    Jirjis, R
    Reasons for slagging during stemwood pellet combustion and some measures for prevention2004In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 27, no 6, p. 597-605Article in journal (Refereed)
    Abstract [en]

    Ash related problems have more than occasionally been observed in pellet burners during the last years. These problems lead to reduced accessibility of the appliances and also bad publicity for the pellet market. The objectives of the present work were therefore to: (i) determine the critical levels of the problematic ash components in stemwood pellets regarding slagging, (ii) document the variations of these problematic elements in the outgoing pellets from two pellet-mills during one operational season, (iii) determine how frequently these elements exceed the critical levels, (iv) determine how different sub-processes in the pelletising process (especially the dryer) effect the slagging properties of the pellet, and if possible (v) suggest some measures for prevention. A significant number of wood pellets reported to be problematic and problem-free, regarding slagging in ordinary residential pellet burners, were collected from the Swedish market. The ash compositions of these fuels were analysed and the results compiled in a database. Partial Least-Squares Discriminant Analysis (PLS-DA) and F-tests were used to statistically identify both the critical ash components and the critical levels of these components that separated the two reported classes. In addition, chemical equilibrium model calculations were used to interpret the findings. The variations of these elements in the in-going raw material and in the produced pellets were determined during one season in two pellet mills equipped with exhaust gas dryers. The results showed that the problematic wood-pellets had a significantly higher amount of Si, but also Al and Fe, in the fuel ash. The critical level of Si (given as SiO2) was about 20-25 wt% of the fuel ash, i.e. pellets with levels in or over this range resulted in slagging problems in residential burners. This critical Si content was exceeded once and twice for the analysed samples in the two studied pellet mills. In one of the studied mills, this was because of contamination by sand of the raw material during storage and handling, and in the other mill the reason was found to be contamination of the raw material by elutriated particles from the dryer fuel. The major conclusion of the work is that both raw materials and drying fuels/processes should be carefully treated to avoid mineral contamination, and an additional cyclone separator could potentially also be used to improve the pellet quality.

  • 36.
    Östman, Marcus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Fick, Jerker
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Detailed mass flows and removal efficiencies for biocides and antibiotics in Swedish sewage treatment plants2018In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 640, p. 327-336Article in journal (Refereed)
    Abstract [en]

    Antimicrobial compounds, such as biocides and antibiotics, are widely used in society with significant quantities of these chemicals ending up in sewage treatment plants (STPs). In this study, mass flows and removal efficiency in different treatment steps at three Swedish STPs were evaluated for eleven different biocides and antibiotics. Mass flows were calculated at eight different locations (incoming wastewater, water after the first sedimentation step, treated effluent, primary sludge, surplus sludge, digested sludge, dewatered digested sludge and reject water). Samples were collected for a total of nine days over three weeks. The STPs were able to remove 53-> 99% of the antimicrobial compounds and 0-64% were biodegraded on average in the three STPs. Quaternary ammonium compounds were removed from the wastewater N99%, partly through biodegradation, but 38-96% remained in the digested sludge. Chlorhexidine was not biodegraded but was efficiently removed from the wastewater to the sludge. The biological treatment step was the most important step for the degradation of the studied compounds, but also removed several compounds through the surplus sludge. Compounds that were inefficiently removed included benzotriazoles, trimethoprim and fluconazole. The study provides mass flows and removal efficiencies for several compounds that have been seldom studied. 

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