Simultaneous removal of Ni(II) As(III) and Sb(III) from spiked mine effluent with metakaolin and blast furnace slag geopolymers.
The mining industry is a major contributor of various toxic metals and metalloids to the aquatic environment. Efficient and economical water treatment methods are therefore of paramount importance. The application of natural or low cost sorbents has attracted a great deal of interest due to the simplicity of its process and its potential effectiveness. Geopolymers represent an emerging group of sorbents. In this study, blast furnace slag and metakaolin geopolymers and their raw materials were tested for simultaneous removal of Ni(II) As(III) and Sb(III) from spiked mine effluent. Blast furnace slag geopolymer proved to be the most efficient of the studied materials: the experimental maximum sorption capacities for Ni, As and, Sb were 3.74 mg/g, 0.52 mg/g, and 0.34 mg/g, respectively. Although the capacities were relatively low due to the difficult water matrix, 90 100% removal of Ni, As, and Sb was achieved when the dose of sorbent was increased appropriately. Removal kinetics fitted well with the pseudo second order model. Our results indicate that geopolymer technology could offer a simple and effective way to turn blast furnace slag to an effective sorbent with a specific utilization prospect in the mining industry.
Journal of environmental management