Sulphate removal over barium-modified blast-furnace-slag geopolymer.
Blast-furnace slag and metakaolin were geopolymerised, modified with barium or treated with a combination of these methods in order to obtain an efficient SO4(2-) sorbent for mine water treatment. Of prepared materials, barium-modified blast-furnace slag geopolymer (Ba-BFS-GP) exhibited the highest SO4(2-) maximum sorption capacity (up to 119mgg(-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 SO4(2-) 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 SO4(2-) (<2mgL(-1)) in mine effluents.
University of Oulu, Research Unit of Sustainable Chemistry, P.O. Box 3000, FI-90014, Finland.
Hanna
H
Runtti
Kajaani University of Applied Sciences, P.O. Box 52, FI-87101 Kajaani, Finland.
Tero
T
Luukkonen
University of Oulu, Research Unit of Sustainable Chemistry, P.O. Box 3000, FI-90014, Finland.
Mikko
M
Niskanen
University of Oulu, Research Unit of Sustainable Chemistry, P.O. Box 3000, FI-90014, Finland.
Sari
S
Tuomikoski
University of Oulu, Research Unit of Sustainable Chemistry, P.O. Box 3000, FI-90014, Finland.
Teija
T
Kangas
University of Jyvaskylä, Kokkola University Consortium Chydenius, Unit of Applied Chemistry, Talonpojankatu 2B, FI-67100 Kokkola, Finland.
Pekka
P
Tynjälä
University of Oulu, Research Unit of Sustainable Chemistry, P.O. Box 3000, FI-90014, Finland; Kajaani University of Applied Sciences, P.O. Box 52, FI-87101 Kajaani, Finland.
Emma-Tuulia
ET
Tolonen
Kajaani University of Applied Sciences, P.O. Box 52, FI-87101 Kajaani, Finland.
Minna
M
Sarkkinen
Kajaani University of Applied Sciences, P.O. Box 52, FI-87101 Kajaani, Finland.
Kimmo
K
Kemppainen
University of Oulu, Research Unit of Sustainable Chemistry, P.O. Box 3000, FI-90014, Finland.
Jaakko
J
Rämö
University of Oulu, Research Unit of Sustainable Chemistry, P.O. Box 3000, FI-90014, Finland; University of Jyvaskylä, Kokkola University Consortium Chydenius, Unit of Applied Chemistry, Talonpojankatu 2B, FI-67100 Kokkola, Finland. Electronic address: ulla.lassi@oulu.fi.
Ulla
U
Lassi
Adsorption; Blast-furnace slag; Geopolymer; Metakaolin; Sulphate