Table 7.
TOC and TN removals for decolorization of Ponceau 4R at optimal conditions and blank tests.
| Test | Reaction conditions | Removal, (%) |
|
|---|---|---|---|
| TOC | TN | ||
| Co(II) + NaHCO3 + H2O2 (optimal conditions) |
BAP system under optimal conditions: Co(II) concentration of 11.16 µM, 4.73 times the stoichiometric H2O2 dosage and 1.69 of molar ratio H2O2/NaHCO3. | 13.91±1.04 | 19.63±0.78 |
| Co(II) + NaOH + H2O2 (Blank test) |
This test was performed in the absence of NaHCO3 adjusting the pH of dye solution (20 mg/l) to 8.3 through the addition of 0.1 M NaOH. Co(II) concentration and H2O2 dosage were 11.16 µM and 4.73 times the stoichiometric dosage. | 0.64±0.13 | 1.2 ± 0.47 |
| Co(II) + H2O2 (Blank test) |
This test was performed in the absence of NaHCO3 (pH was not controlled). The dye solution (20 mg/l) was added with a Co(II) concentration of 11.16 µM and 4.73 times the stoichiometric dosage of H2O2. | ND | ND |
| H2O2 + NaHCO3 (Blank test) |
This test was performed in the absence of Co(II). The dye solution (20 mg/l) was added with 4.73 times the stoichiometric dosage of H2O2 and an amount of NaHCO3 that guaranteed an nH2O2/nNaHCO3 of 1.70. | ND | ND |
ND: Not detected.