| 1. |
- Alecrim, Viviane, et al.
(författare)
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Exfoliated Layered Materials for Digital Fabrication
- 2015
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Ingår i: NIP & Digital Fabrication Conference. ; , s. 192-194
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Konferensbidrag (refereegranskat)abstract
- We introduced an exfoliation method of MoS2 in a 3% solution of sodium dodecyl surfactant at high concentration (i.e. 2 g/L). The bulk MoS2 was thinned by mechanical exfoliation between sand papers and the resulting powder was used to prepare dispersions by liquid exfoliation through probe sonication. The resulting dispersion consisted of very thin MoS2 nanosheets in surfactant solution with average lateral size around 126 nm. This may be interesting for applications in inkjet printed electronics.
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| 2. |
- Andersson, Kerstin, et al.
(författare)
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Effects of biological treatment on the chemical structure of dissolved lignin-related substances in effluent from thermomechanical pulping
- 2008
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Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 23:2, s. 164-171
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Tidskriftsartikel (refereegranskat)abstract
- Effluent from a TMP-based pulp and paper mill was collected at the inlet and outlet of the mill's biological treatment plant and fractionated by sorption on XAD-8 resin and MTBE precipitation. Fractionation indicated that the refractory dissolved organic material in biologically treated effluent was mainly composed of lignin-related substances. Characterisation of the lignin-related substances by chromatographic and spectrometric methods confirmed the similarities of the isolated material and milled wood lignin. Fractionation and characterisation of alkali-extracted material from solids (biosludge) in biologically treated effluent found evidence of lignin-related material. Results indicated that biological treatment had altered the chemical structure and molar-mass distribution of dissolved lignin-related substances.
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| 3. |
- Andersson, Kerstin I, et al.
(författare)
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Lignin removal from wastewater by adsorption
- 2009
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Ingår i: Proceedings - 2009 International Mechanical Pulping Conference, IMPC 2009. ; , s. 280-285
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Konferensbidrag (refereegranskat)abstract
- Lignin contributes to residual COD in wastewater after biological treatment. Available methods for removal of recalcitrant material like lignin, e.g. chemical oxidation and coagulation, are associated with heavy operational expenses. Stringent discharge requirements demand new cost-effective methods for removal of recalcitrant COD. Adsorption is an important mechanism for lignin removal in biological wastewater treatment. A study of lignin, using activated carbon as a model adsorbent, was performed to learn more about the adsorption behaviour of lignin. At the adsorbent dose 4 g/L and an initial lignin concentration of 0.5 g/L, 77% of the lignin was removed after six hours. The adsorption kinetics was found to follow the pseudo second-order rate expression and no temperature dependency could be observed in the temperature range studied.
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| 4. |
- Andersson, Kerstin I., et al.
(författare)
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Removal of Lignin from Wastewater Generated by Mechanical Pulping Using Activated Charcoal and Fly Ash : Adsorption Kinetics
- 2011
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Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 0888-5885 .- 1520-5045. ; 50:13, s. 7733-7739
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Tidskriftsartikel (refereegranskat)abstract
- The possible application of adsorption for the removal of lignin-related material found in wastewater generated by mechanical pulping was investigated. Activated charcoal and fly ash were used as adsorbents in batch experiments. The lignin-related material exhibited properties well-suited for adsorption onto both adsorbents, although the sorption capacity of activated charcoal exceeds that of fly ash. The experimental data were fitted to pseudo-first- and pseudo-second-order rate kinetic expressions, and an attempt was made to find the rate-limiting step involved in the adsorption processes. The results showed that lignin adsorption onto both activated charcoal and fly ash follows pseudo-second-order rate kinetics and that both boundary-layer diffusion and intraparticle diffusion are likely involved in the rate-limiting mechanisms. Adsorption is an interesting option in advanced wastewater treatment, and fly ash appears to be a suitable low-cost adsorbent for recalcitrant organic pollutants.
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| 5. |
- Andersson, Kerstin I, et al.
(författare)
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Removal of Lignin from Wastewater Generated by Mechanical Pulping Using Activated Charcoal and Fly Ash: Adsorption Isotherms and Thermodynamics
- 2011
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Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 0888-5885 .- 1520-5045. ; 50:13, s. 7722-7732
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Tidskriftsartikel (refereegranskat)abstract
- Lignin-related material found in wastewater from thermomechanical pulping resists conventional biological treatment, entailing the use of advanced removal methods. In this work, the use of adsorption for removing lignin-related material was investigated. Activated charcoal and fly ash were used to study the adsorption behavior of lignin and to determine the adsorption capacities of these two adsorbents. Experimental data were fitted to various isotherm equations to find the best description of the sorption systems, and the corresponding thermodynamic parameters were calculated. Fly ash exhibited good sorption properties, although its sorption capacity was inferior to that of activated charcoal. Both the Freundlich and Langmuir equations provided reasonable models of the sorption processes, and the thermodynamic parameters indicated that sorption onto activated charcoal is endothermic, whereas sorption onto fly ash appears to be exothermic. Fly ash is a low-cost material that is often available on-site and offers an interesting alternative to high-cost advanced wastewater treatment systems for removing recalcitrant organic materials.
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| 6. |
- Andres, Britta, 1986-, et al.
(författare)
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Cellulose binders for electric double-layer capacitor electrodes : The influence of cellulose quality on electrical properties
- 2018
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Ingår i: Materials & design. - : Elsevier BV. - 0264-1275 .- 1873-4197. ; 141, s. 342-349
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Tidskriftsartikel (refereegranskat)abstract
- Cellulose derivatives are widely used as binders and dispersing agents in different applications. Binders composed of cellulose are an environmentally friendly alternative to oil-based polymer binding agents. Previously, we reported the use of cellulose nanofibers (CNFs) as binders in electrodes for electric double-layer capacitors (EDLCs). In addition to good mechanical stability, we demonstrated that CNFs enhanced the electrical performance of the electrodes. However, cellulose fibers can cover a broad range of length scales, and the quality requirements from an electrode perspective have not been thoroughly investigated. To evaluate the influence of fiber quality on electrode properties, we tested seven samples with different fiber dimensions that are based on the same kraft pulp. To capture the length scale from fibers to nanofibrils, we evaluated the performance of the untreated kraft pulp, refined fibers, microfibrillated cellulose (MFC) and CNFs. Electrodes with kraft pulp or refined fibers showed the lowest electrical resistivity. The specific capacitances of all EDLCs were surprisingly similar, but slightly lower for the EDLC with CNFs. The same electrode sample with CNFs also showed a slightly higher equivalent series resistance (ESR), compared to those of the other EDLCs. Graphite dispersions with MFC showed the best dispersion stability.
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| 7. |
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| 8. |
- Boija, Susanne, et al.
(författare)
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Determination of conditional stability constants for some divalent transition metal ion-EDTA complexes by electrospray ionization mass spectrometry
- 2014
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Ingår i: Journal of Mass Spectrometry. - : Wiley. - 1076-5174 .- 1096-9888. ; 49:7, s. 550-556
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Tidskriftsartikel (refereegranskat)abstract
- Conditional stability constants of coordination complexes comprising divalent transition metals, Cu2+, Ni2+, Zn2+, Co2+, and ethylenediaminetetraacetic acid (EDTA) were determined utilizing electrospray ionization mass spectrometry. The deviation of signal response of a reference complex was monitored at addition of a second metal ion. The conditional stability constant for the competing metal was then determined through solution equilibria equations. The method showed to be applicable to a system where Co2+ and Zn2+ competed for EDTA at pH 5. When Cu2+ and Ni2+ competed for EDTA, the equilibrium changed over time. This change was shown to be affected in rate and size by the type of organic solvent added. In this work, 30% of either methanol or acetonitrile was used. It was found that if calibration curves are prepared for both metal complexes in solution and the measurements are repeated with sufficient time space, any change in equilibrium of sample solutions will be discovered. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.
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