| Title |
Sorption of arsenate on ettringite formed in sulphate removal from mine drainage water |
| ID_Doc |
10768 |
| Authors |
Tolonen, ET; Luukkonen, T; Runtti, H; Rämö, J; Lassi, U |
| Title |
Sorption of arsenate on ettringite formed in sulphate removal from mine drainage water |
| Year |
2016 |
| Published |
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| Abstract |
There is a current need for effective treatment methods for water pollutants such as sulphate and arsenic. Circular economy thinking is also increasing. Ideally, waste from one stream could be valuable in another. The aim of this research was to investigate arsenate sorption on ettringite formed in sulphate removal from underground gold mine drainage water. Batch sorption experiments were conducted at room temperature using a synthetic solution with an initial As(V) concentration of 1.7 +/- 0.1 mg/L, which was chosen to model typical arsenate containing mine water. The effect of ettringite dosage was studied, and Langmuir and Freundlich sorption isotherms were fitted to the results. The maximum sorption capacity (1.8 mg/g) of the ettringite was determined from the Langmuir isotherm, which corresponded well with the maximum experimental sorption capacity. Furthermore, the effect of contact time was studied, and pseudo-first order and pseudo-second order kinetic models were fitted to the experimental data. The kinetics of the arsenate sorption on ettringite were best described by the pseudo-second order model. This paper offers one possible method of extracting value from mine water, as its results indicate that the precipitate produced during sulphate removal from mine water by precipitation as ettringite could be further used as a sorbent for arsenate removal from aqueous solutions. |
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