Preparation of filter by alkali activation of blast furnace slag and its application for dye removal
Bhuyan, M. A. H.; Gebre, R. K.; Finnilä, M. A. J.; Illikainen, M.; Luukkonen, T. (2021-12-22)
M.A.H. Bhuyan, R.K. Gebre, M.A.J. Finnilä, M. Illikainen, T. Luukkonen, Preparation of filter by alkali activation of blast furnace slag and its application for dye removal, Journal of Environmental Chemical Engineering, Volume 10, Issue 1, 2022, 107051, ISSN 2213-3437, https://doi.org/10.1016/j.jece.2021.107051
© 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
https://creativecommons.org/licenses/by-nc-nd/4.0/
https://urn.fi/URN:NBN:fi-fe202201031031
Tiivistelmä
Abstract
This study demonstrates a high-value valorization of blast furnace slag in foamed alkali-activated filters for adsorption applications, using methylene blue as a model compound. The filters were prepared by combining alkali activation of blast furnace slag with direct foaming, followed by curing at 60 °C for 4 h. Five different surfactants were compared for the stabilization of foams. Based on an initial screening, the Triton X-405 surfactant was selected for further studies. The dosages of selected surfactant and H₂O₂ were optimized to obtain compressive strength of 2.59 MPa and specific surface area of 83.3 m²/g for powdered material and 78.31 m²/g for foam pieces. Porosity was determined as 64%, 65%, or 50% by using gas pycnometry, Archimedes method, or X-ray microtomography, respectively. The optimized filter mix design was applied for methylene blue removal in continuous column experiments at two influent concentrations (5 and 10 ppm) by using constant empty-bed contact time of ~9 min (flowrate of ~1 L/h). After 6 h, for both influent concentrations, the dye removal was still 74%, with the initial removal of ~100%. The saturated filter could be regenerated by a thermal treatment resulting improved adsorption performance. When the material was employed as powder, the maximum adsorption capacity was 60.35 mg/g according to the Langmuir isotherm (R² = 0.99) and adsorption kinetics followed the pseudo-second order model. The results demonstrate preliminarily that porous filters prepared in this study have potential to be used in industrial wastewater treatment.
Kokoelmat
- Avoin saatavuus [32009]