Table 1 Dried sludge compositions
Element | Content mg g−1 dried sludge | Fraction wt-% | |||
|---|---|---|---|---|---|
CHES | BIOS | CHES | BIOS | ||
P | of which | 59.2 ± 4.3 | 45.3 ± 2.8 | 5.9 | 4.5 |
OP | 7 | 24 | |||
IP | 93 | 76 | |||
Al | 113.4 ± 14.7 | 19.2 ± 2.4 | 11.3 | 1.9 | |
Ca | 32.2 ± 4.2 | 28 ± 2.3 | 3.2 | 2.8 | |
Fe | 11.7 ± 7.5 | 10.02 ± 2.6 | 1.2 | 1.0 | |
Mn | 0.4 ± 0.1 | 0.6 ± 0.03 | 0.04 | 0.06 | |
Zn | 1.4 ± 0.2 | 1.5 ± 0.3 | 0.14 | 0.15 | |
K | 8.4 ± 2.8 | 8.7 ± 1.3 | 0.08 | 0.09 | |
Cu | 0.143 ± 0.02 | 0.130 ± 0.06 | 0.014 | 0.013 | |
Cr | 0.167 ± 0.02 | 0.014 ± 0.005 | 0.017 | 0.014 | |
Cd | 9 × 10–4 ± 2 × 10–4 | BDL | 9 × 10–5 | BDL | |
Pb | 0.034 ± 4.7 × 10–3 | BDL | 3.4 × 10–3 | BDL | |