Table 1.
Physicochemical characteristics of WAS and influent wastewater.
| Treatments | ||||
|---|---|---|---|---|
| Parameter | Control WAS | Metal spiked WAS | ENP spiked WAS | Influent |
| Ag+ (mg L−1)* | n.d. | 33.3 ± 0.4 | n.d. | n.a. |
| Ti4+ (mg L−1)* | n.d. | n.d. | n.d. | n.a. |
| Zn2+ (mg L−1)* | n.d. | 500 ± 400 | n.d. | n.a. |
| Ag+ (mg kg MLSS−1) | 10 ± 0.0 | 32 ± 1.7 | 100 ± 30 | n.a. |
| Ti4+ (mg kg MLSS−1) | 1400 ± 372 | 1810 ± 597 | 3678 ± 766 | n.a. |
| Zn2+ (mg kg MLSS−1) | 244 ± 17 | 656 ± 283 | 1022 ± 134 | n.a. |
| Conductivity (μS) | 730 ± 65 | 761 ± 48 | 740 ± 66 | 929 ± 53 |
| Effluent pH | 6.5 ± 0.2 | 6.45 ± 0.3 | 6.69 ± 0.4 | 8.06 ± 0.1 |
| NH3− (mg L−1) | 0.2 ± 0.1 | 0.8 ± 1.6 | 0.17 ± 0.9 | 37 ± 6 |
| SVI (mL g−1) | 85 ± 27 | 152 ± 68 | 100 ± 28 | na |
| TSS (mg L−1)* | 32 ± 11 | 51 ± 17 | 33 ± 12 | na |
Values are mean ± standard deviation of ENPs and metal salts partitioned into WAS from 315 days of treatment. * = concentration in effluent, n.d. = not detected; n.a. = not applicable.