Table 2.
Linear combination fitting (LCF) results of the Cu K-edge XANES spectra acquired from soils spiked with dissolved Cu(NO3)2 (top) and CuO-NPs (bottom). The LCF results are shown as percentage composition of the total Cu in terms of the listed standards. FeO(OH) indicates any ferric oxyhydroxide (in this case, Cu-Fh and Cu-Gt have been summed). Note that LCF contributions of <10% are not considered significant due to the inherent errors in the LCF procedure. They have, however, been listed for completeness.
| Cu(NO3)2 | BARREN GROUND | LENSWOOD | HAMILTON | PIMPINIO | MINNIPA | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Components | Day 0 | Day 3 | Day 5 | Day 0 | Day 3 | Day 5 | Day 0 | Day 3 | Day 5 | Day 0 | Day 3 | Day 5 | Day 0 | Day 3 | Day 5 |
| CuO (NPs) | |||||||||||||||
| Cu-FeO(OH) | 88.7 | 55.8 | 48.2 | 28.7 | 35.9 | 32.3 | 34 | 43.5 | 31.4 | 40.3 | 19.3 | ||||
| NOM† | 38.2 | 46.2 | 39.3 | 62.6 | 61.8 | 45.4 | 37.1 | 54.2 | 47.8 | 21.5 | 50.9 | ||||
| CuCO3 | 51.4 | 51.2 | 50.6 | 20.7 | |||||||||||
| Cu2S | 31.9 | 1.4 | 5.9 | 11.8 | 12.9 | 8.7 | 15 | 15.5 | 16.1 | 16.7 | 17.5 | 13.5 | |||
| Cu(OH)2 | 8.8 | 7.2 | 6.5 | 36.2 | 43.2 | 35.0 | 37.4 | 17.2 | |||||||
| Cu-HA | 11.3 | 6.2 | 6.1 | ||||||||||||
|
| |||||||||||||||
| Day 0 fraction‡ | 54.7 | 54.3 | 4.3 | 18.4 | 81.7 | 73.5 | 52.5 | 64.9 | 45.9 | ||||||
|
| |||||||||||||||
| SUM | 100.0 | 100.2 | 100.5 | 100.1 | 99.9 | 100.0 | 100.0 | 100.7 | 100.7 | 102.6 | 109.9 | 101.7 | 101.9 | 100.0 | 100.9 |
| R-factor | 5.0E-04 | 3.8E-05 | 4.7E-05 | 7.0E-04 | 7.6E-05 | 1E-04 | 1.9E-04 | 1.6E-04 | 9.8E-05 | 8.8E-04 | 2.6E-04 | 1.9E-04 | 2.8E-04 | 3.7E-04 | 7.7E-05 |
|
| |||||||||||||||
| CuO-NPs | BARREN GROUND | LENSWOOD | HAMILTON | PIMPINIO | MINNIPA | ||||||||||
| Components | Day 0 | Day 3 | Day 5 | Day 0 | Day 3 | Day 5 | Day 0 | Day 3 | Day 5 | Day 0 | Day 3 | Day 5 | Day 0 | Day 3 | Day 5 |
|
| |||||||||||||||
| CuO (NPs) | 73.2 | 83.9 | 81.2 | 41.1 | 26.5 | 97.1 | 60.7 | 46.2 | |||||||
| Cu-FeO(OH) | 22.9 | 40.8 | 24.3 | 33.5 | 28.4 | 13.7 | 39.1 | 40.7 | 17.6 | 39.4 | 60.7 | 4.3 | 20.9 | 28.9 | |
| NOM† | 75.7 | 59.2 | 67.3 | 67.2 | 67.4 | 56.7 | 51.2 | 13.0 | 10.8 | 16.8 | |||||
| CuCO3 | |||||||||||||||
| Cu2S | 5 | 8.4 | 4.2 | 5.4 | 4.2 | 8.1 | 3.2 | 6.4 | 14.0 | 7.7 | 10.1 | ||||
| Cu3(PO4)2 | 4.0 | ||||||||||||||
| Cu(OH)2 | 20.3 | ||||||||||||||
| Cu-HA | |||||||||||||||
|
| |||||||||||||||
| SUM | 101.1 | 100.0 | 100.0 | 100.0 | 100.7 | 100.0 | 103.0 | 100.0 | 100.0 | 102.0 | 99.9 | 101.2 | 101.4 | 100.1 | 102.0 |
| R-factor | 7.4E-05 | 7.8E-05 | 1.0E-04 | 4.7E-04 | 9.3E-05 | 1.2E-04 | 1.6E-04 | 1.0E-04 | 1.5E-04 | 2.2E-04 | 1.7E-04 | 2.8E-04 | 1.5E-04 | 6.7E-05 | 8.6E-05 |
†
NOM is the sum of the percentage contributions from native SR-NOM and SR-NOM dialysed with Cu(NO3)2.
‡
Day 0 fraction is the percentage attributed by the LCF to the corresponding Day 0 spectrum before distributing to other components.