Table 2.
Characteristics | Sewage Sludge Treatment | ||||
---|---|---|---|---|---|
Control (0 g/kg) | 50 g/kg | 100 g/kg | 150 g/kg | 200 g/kg | |
pH | 7.31 ± 0.01 | 7.19 ± 0.01 a | 7.05 ± 0.03 a | 6.77 ± 0.02 a | 6.50 ± 0.02 a |
Electrical conductivity (dS/m) | 5.31 ± 0.04 | 5.61 ± 0.01 a | 6.03 ± 0.03 a | 6.29 ± 0.03 a | 6.51 ± 0.03 a |
Organic carbon (g/kg) | 10.10 ± 0.61 | 12.41 ± 0.73 a | 14.76 ± 0.58 a | 20.15 ± 1.03 a | 23.44 ± 0.82 a |
TKN (g/kg) | 0.56 ± 0.04 | 0.70 ± 0.05 a | 0.84 ± 0.09 a | 0.94 ± 0.06 a | 1.12 ± 0.10 a |
Cu (mg/kg) | 5.07 ± 0.03 | 6.53 ± 1.16 b | 10.53 ± 0.16 a | 13.40 ± 0.15 a | 16.24 ± 0.08 a |
Cr (mg/kg) | 2.75 ± 0.01 | 3.24 ± 0.03 a | 3.75 ± 0.05 a | 4.31 ± 0.06 a | 4.80 ± 0.04 a |
Cd (mg/kg) | 0.15 ± 0.01 | 0.26 ± 0.01 a | 0.40 ± 0.01 a | 0.52 ± 0.01 a | 0.64 ± 0.01 a |
Fe (mg/kg) | 16.68 ± 0.09 | 19.25 ± 0.06 a | 21.61 ± 0.26 a | 24.32 ± 0.18 a | 27.16 ± 0.14 a |
Mn (mg/kg) | 5.80 ± 0.01 | 6.40 ± 0.01 a | 7.05 ± 0.04 a | 7.60 ± 0.02 a | 8.21 ± 0.01 a |
Zn (mg/kg) | 3.05 ± 0.01 | 8.98 ± 0.03 a | 14.79 ± 0.14 a | 20.88 ± 0.17 a | 26.61 ± 0.12 a |
Values are mean ± SD of three analyses; a and b: Significantly different and not different from the control group at p < 0.05 and p > 0.5.