| 1. |
- Kaur, Parminder, et al.
(författare)
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Photoelectrocatalytic treatment of municipal wastewater with emerging concern pollutants using modified multi-layer catalytic anode
- 2023
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Ingår i: Chemosphere. - : Elsevier Ltd. - 0045-6535 .- 1879-1298. ; 339
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Tidskriftsartikel (refereegranskat)abstract
- Municipal wastewater contains emergent chemical and biological pollutants that are resistant to conventional wastewater treatments. Therefore, the focus of the current study was to address the challenge of removing emergent chemical and biological pollutants present in municipal wastewater. To achieve this, a photo electro-catalytic (PEC) treatment approach was employed, focusing on the removal of both micro and biological pollutants that are of emergent concern, as well as the reduction of Chemical Oxidation Demand (COD) and Total Organic Carbon (TOC). The treatment involved the use of a modified multi-layer catalytic anode photo-electroactive anode as an effective anode for PEC treatment of municipal wastewater. In the continuous mode of operation, %COD removal was optimized for the treatment of municipal wastewater under Ultra-Violet C (UVc), 280 nm, and Visible (Vis) radiation, 400 nm. Therefore, a comparative study was performed to investigate the effect of Vis radiation on %COD removal, micropollutants removal, and disinfection of municipal wastewater. Micropollutants present in municipal wastewater were effectively oxidized/degraded with the highest reduction rate between 100% and 80% under the influence of UVc and Vis radiation respectively by the PEC treatment process. Disinfection of various microorganisms present in the wastewater with the effect of UVc and Vis assisted PEC treatment was also monitored. Overall, 75–80% of the disinfection of municipal wastewater was contributed by the modified multi-layer catalytic anode. The UVc in the PEC system, contributes approximately 20–25% to the overall disinfection of municipal wastewater.
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| 2. |
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| 3. |
- Lipnizki, Frank, et al.
(författare)
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Membrane processes and applications for biorefineries
- 2019
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Ingår i: Current Trends and Future Developments on (Bio-) Membranes : Membranes in Environmental Applications - Membranes in Environmental Applications. - 9780128167786 - 9780128167786 ; 1, s. 283-301
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Bokkapitel (refereegranskat)abstract
- The chapter provides an overview of membrane applications in conventional and lignocellulosic biorefineries. Driven by the trend towards “white biotechnology” the market and applications for membrane processes in biorefineries are growing rapidly since membrane processes have been identified as energy-efficient and highly selective separation processes in the different stages of biorefining. The applications of membrane processes in biorefineries cover the pre-treatment of the raw materials, the product recovery after reaction and the downstream processing plus in-take water preparation and wastewater treatment. The first part of the chapter will focus on conventional biorefineries using starch and sugars as well as vegetable oils as raw materials to produce bioethanol, biodiesel and biochemicals. In the second part of the chapter the focus is on lignocellulosic biorefineries using e.g. wood and agricultural raw materials. Overall, the chapter demonstrates that membrane processes have a great potential in current conventional biorefineries but also in the increasingly important concepts of lignocellulosic biorefineries.
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| 4. |
- Liu, Qinghua, et al.
(författare)
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Advanced electrolyte-free fuel cells based on functional nanocomposites of a single porous component : analysis, modeling and validation
- 2012
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 2:21, s. 8036-8040
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Tidskriftsartikel (refereegranskat)abstract
- Recently, a fuel cell device constructed with only one layer composited of ceria-based nanocomposites (typically, lithium nickel oxide and gadolinium doped ceria (LiNiO2-GDC) composite materials), called an electrolyte-free fuel cell (EFFC), was realized for energy conversion by Zhu et al. The maxium power density of this single-component fuel cell is 450 mW cm(-2) at 550 degrees C when using hydrogen fuel. In this study, a model was developed to evaluate the performance of an EFFC. The kinetics of anodic and cathodic reactions were modeled based on electrochemical impedance spectroscopy (EIS) measurements. The results show that both of the anodic and cathodic reactions are kinetically fast processes at 500 degrees C. Safety issues of an EFFC using oxidant and fuels at the same time without a gas-tight separator were analyzed under open circuit and normal operation states, respectively. The reaction depth of anodic and cathodic processes dominated the competition between surface electrochemical and gas-phase reactions which were effected by the catalytic activity and porosity of the materials. The voltage and power output of an EFFC were calculated based on the model and compared with the experimental results.
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| 5. |
- Xia, Chen
(författare)
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Development of Natural Mineral Composites for Low-Temperature Solid Oxide Fuel Cells
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Solid oxide fuel cells (SOFCs) have attracted growing attention worldwide because of their high conversion efficiency and low emissions when paired with clean fuel sources. Currently, reducing the temperature of SOFC to a low-temperature (LT) range is a mainstream trend of SOFC research. One effective way to reach this target is to explore alternative electrolytes that can maintain a desirable ionic conductivity at low temperatures. Meanwhile, it has been found that natural minerals hold great potential as functional materials for energy conversion technologies, especially ion-conducting hematite and rare-earth oxides. This thesis presents an experimental investigation of novel composite electrolytes based on two common natural minerals: hematite (LW) (α-Fe2O3) and La0.33Ce0.62Pr0.05O2-δ (LCP) for LT-SOFCs application. Initially, hematite (LW) and LCP are characterized and demonstrated as electrolytes in SOFCs. It is found the hematite ore is a mixture of α-Fe2O3, silica, and calcite, while the LCP mineral is a La/Pr co-doped CeO2. Both hematite (LW) and LCP cells exhibit encouraging performance with power densities of 150-225 and 295-401 mW cm-2 at 500-600 ℃, respectively.Following above findings, two mineral based nanocomposites – hematite-LCP and LCP/K2WO4 – are developed. Electrochemical and electrical studies reveal that the hematite-LCP gains a significantly enhanced conductivity (0.116 S cm-1 at 600 ℃) compared to individual hematite (LW) and LCP. The hematite-LCP based SOFC exhibits attractive power densities of 386-625 mW cm-2 at 450-600 ℃. Further investigation indicates that heterophasic interfacial conduction plays a crucial role in resulting in the good performance. Another composite LCP/K2WO4 is synthesized from LCP and tungstate through a wet-chemical route. The obtained composites exhibit enhanced grain boundary conduction compared to that of LCP. The composition dependence of the electrical conductivity has been studied, indicating that 90 wt% LCP/10 wt% K2WO4 is the optimum proportion with highest ionic conductivity and negligible electronic conductivity. The corresponding SOFC displays the highest power density of 500 mW cm-2 at 550 ℃. Furthermore, by incorporating a semiconductor La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) into LCP and hematite-LCP, respectively, two semiconducting-ionic composites LCP-LSCF and hematite/LCP-LSCF are designed. Crystallographic and morphological characterizations are carried out to gain insight into the material features, and the two composites are applied as the intermediate membrane layer in LT electrolyte-layer free fuel cells (EFFCs). Investigations in terms of conductivity and fuel cell performance reveal that the two composites obtain improved ionic conductivities and cell power outputs compared with those of LCP and hematite-LCP. It is also found the two composites possess mixed ionic and electronic conductivities, which are balanced in the optimal composites. Additionally, stability and Schottky junction of the best-performance EFFC are studied to verify its reliability.
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