Table 1 Solids characterization using hot HCl extraction, XRD and XANES for all experiments at 0 day (initial), 21 days and 63 days (n.d.: no data).
AD1 | CP1 | AD5 | CP5 | |
|---|---|---|---|---|
Synthesis mechanism | Adsorption | Co-precipitation | Adsorption | Co-precipitation |
Initial solid As (mM)1 | 0.17 | 0.17 | 0.84 | 0.84 |
Initial solid Fe (mM)1 | 3.06 | 3.06 | 15.3 | 15.3 |
Initial molar solid As/Fe (%)1 | 5.48 | 5.48 | 5.55 | 5.55 |
Initial solid As(III)/As (%)2 | < 5 | < 5 | < 5 | < 5 |
After 21 days solid As(III)/As (%)2 | 9 | 8 | n.d. | n.d. |
After 63 days solid As(III)/As (%)2 | 16 | n.d. | 29 | n.d. |
Initial solid composition3 | 2LFh | 2LFh | 2LFh | 2LFh |
After 21 days solid composition3 | 2LFh | 2LFh | 2LFh | 2LFh |
After 63 days solid composition3 | 2LFh, Vivianite, Bobierrite | 2LFh, Vivianite | 2LFh | 2LFh |