Table 2.
Test | Extraction condition | Extraction buffer | %recovery of Cr(VI) (Mean ± SD, N = 3)
|
|
---|---|---|---|---|
PbCrO4 | BaCrO4 | |||
1 | 15 min Ramping to 95°C and holding for 1 hr, pressure less than 220 psi | 3% Na2CO3-2% NaOH | 95.0 ± 5.5% | 78.0 ± 3.1% |
2 | 15 min Ramping to 60°C and holding for 1 hr, pressure less than 200 psi | 43.7 ± 8.3% | 16.5 ± 5.4% | |
3 | 15 min Ramping to 95°C and holding for 40 min, pressure less than 200 psi | 81.3 ± 1.8% | 42.3 ± 0.5% | |
| ||||
4 | 15 min Ramping to 95°C and holding for 1 hr, pressure less than 220 psi | 1:2.5 diluted 3% Na2CO3-2% NaOH |
62.8 ± 6.0% | 57.2 ± 8.8% |
5 | 1:5 diluted 3% Na2CO3-2% NaOH |
55.1 ± 7.0% | 39.5 ± 6.2% |