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2006
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2016
Anodes fabricated from a single source coke were used for investigations of effect of porosity and surface roughness on the electrochemical performance in laboratory scale cells. In order to fabricate anodes differing in porosity, the production parameters were varied with two levels of mixing temperatures (150 and 210 °C) and three baking levels (underbaking at 1150°E, normal baking at 1260°E, overbaking at 1350°E). °E denotes the equivalent temperature which is a function of both the temperature the anode sees, and the time kept at this temperature. The low mixing anodes were more inhomogeneous with respect to both micro- and macroporosity, which can be attributed to the wetting between pitch and coke. After electrolysis, the real surface area of the low mixing anodes was about 13% higher than the high mixing anodes. Also, the low mixing electrodes had slightly larger electrochemically active surface area after electrolysis compared to the high mixing electrodes, as evidenced by higher capacitance measured at low current densities. Still, the mixing and equivalent baking temperatures did not affect the electrochemical overpotential at 1 A/cm2 to any significant extent. This could be understood from the 3D computed tomography images, which also showed that the electrolyte does not generally penetrate into the pores on the surface, penetration will depend on the size and shape of the pore.
2019
Carbon felts are flexible and scalable, have high specific areas, and are highly conductive materials that fit the requirements for both anodes and cathodes in advanced electrocatalytic processes. Advanced oxidative modification processes (thermal, chemical, and plasma-chemical) were applied to carbon felt anodes to enhance their efficiency towards electro-oxidation. The modification of the porous anodes results in increased kinetics of acetaminophen degradation in aqueous environments. The utilised oxidation techniques deliver single-step, straightforward, eco-friendly, and stable physiochemical reformation of carbon felt surfaces. The modifications caused minor changes in both the specific surface area and total pore volume corresponding with the surface morphology.
A pristine carbon felt electrode was capable of decomposing up to 70% of the acetaminophen in a 240 min electrolysis process, while the oxygen-plasma treated electrode achieved a removal yield of 99.9% estimated utilising HPLC-UV-Vis. Here, the electro-induced incineration kinetics of acetaminophen resulted in a rate constant of 1.54 h−1, with the second-best result of 0.59 h−1 after oxidation in 30% H2O2. The kinetics of acetaminophen removal was synergistically studied by spectroscopic and electrochemical techniques, revealing various reaction pathways attributed to the formation of intermediate compounds such as p-aminophenol and others.
The enhancement of the electrochemical oxidation rates towards acetaminophen was attributed to the appearance of surface carbonyl species. Our results indicate that the best-performing plasma-chemical treated CFE follows a heterogeneous mechanism with only approx. 40% removal due to direct electro-oxidation. The degradation mechanism of acetaminophen at the treated carbon felt anodes was proposed based on the detected intermediate products. Estimation of the cost-effectiveness of removal processes, in terms of energy consumption, was also elaborated. Although the study was focussed on acetaminophen, the achieved results could be adapted to also process emerging, hazardous pollutant groups such as anti-inflammatory pharmaceuticals.
2022
Eksponeringsutvikling av lokal luftkvalitet i Oslo. Anvendelse av AirQUIS. Powerpoint-presentasjon. NILU F
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2016
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2004
EIF-air. Environmental Impact Factor for assessment of emissions to air. Summary report. NIVA report, 5098-2005
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