Sulphate removal over barium-modified blast-furnace-slag geopolymer
Runtti, H., Luukkonen, T., Niskanen, M., Tuomikoski, S., Kangas, T., Tynjälä, P., . . . Lassi, U. (2016). Sulphate removal over barium-modified blast-furnace-slag geopolymer. Journal of Hazardous Materials, 317, 373-384. doi:10.1016/j.jhazmat.2016.06.001
Published inJournal of Hazardous Materials
© 2016 Elsevier. This is a final draft version of an article whose final and definitive form has been published by Elsevier. Published in this repository with the kind permission of the publisher.
Blast-furnace slag and metakaolin were geopolymerised, modified with barium or treated with a combination of these methods in order to obtain an efficient SO42− sorbent for mine water treatment. Of prepared materials, barium-modified blast-furnace slag geopolymer (Ba-BFS-GP) exhibited the highest SO42− maximum sorption capacity (up to 119 mg g−1) and it compared also favourably to materials reported in the literature. Therefore, Ba-BFS-GP was selected for further studies and the factors affecting to the sorption efficiency were assessed. Several isotherms were applied to describe the experimental results of Ba-BFS-GP and the Sips model showed the best fit. Kinetic studies showed that the sorption process follows the pseudo-second-order kinetics. In the dynamic removal experiments with columns, total SO42− removal was observed initially when treating mine effluent. The novel modification method of geopolymer material proved to be technically suitable in achieving extremely low concentrations of SO42− (<2 mg L−1) in mine effluents. ...