Table 3 Methane production and chemical characterization of effluent after AD
From: Enhanced methane production of vinegar residue by response surface methodology (RSM)
F/I ratio (X1) | Organic loading (X2) (gVS L−1) | Initial pH (X3) | Methane production | Final pH | TAN (mg L−1) | TA (mg CaCO3 L−1) | VFA (mg L−1) | VFA/TA | |
|---|---|---|---|---|---|---|---|---|---|
Experimental value (mL gVS−1) | Predicted value (mL gVS−1) | ||||||||
0.7 | 20 | 6 | 145.27 | 136.50 | 6.78 ± 0.08 | 778.0 ± 38.1 | 3025.0 ± 35.4 | 33.99 ± 7.72 | 0.011 |
0.7 | 20 | 8 | 155.78 | 157.47 | 7.50 ± 0.01 | 809.0 ± 12.7 | 7050.0 ± 106.1 | 31.33 ± 4.38 | 0.004 |
0.7 | 40 | 6 | 159.27 | 152.57 | 7.24 ± 0.04 | 904.5 ± 23.3 | 4962.5 ± 53.0 | 30.38 ± 0.41 | 0.013 |
0.7 | 40 | 8 | 174.79 | 178.10 | 7.87 ± 0.01 | 978.5 ± 14.9 | 9437.5 ± 88.4 | 64.86 ± 1.59 | 0.003 |
1.3 | 20 | 6 | 92.89 | 87.04 | 6.93 ± 0.02 | 491.0 ± 4.2 | 3287.5 ± 17.7 | 70.40 ± 0.13 | 0.021 |
1.3 | 20 | 8 | 103.32 | 107.47 | 7.39 ± 0.03 | 562.0 ± 26.9 | 5087.5 ± 159.1 | 30.20 ± 3.78 | 0.006 |
1.3 | 40 | 6 | 145.35 | 141.11 | 6.89 ± 0.08 | 978.0 ± 18.4 | 3700.0 ± 106.1 | 67.86 ± 1.05 | 0.018 |
1.3 | 40 | 8 | 159.87 | 166.10 | 7.37 ± 0.02 | 820.5 ± 10.6 | 5875.0 ± 141.4 | 52.97 ± 3.24 | 0.009 |
0.5 | 30 | 7 | 198.90 | 203.90 | 7.69 ± 0.06 | 910.0 ± 18.4 | 9337.5 ± 159.1 | 22.27 ± 1.69 | 0.002 |
1.5 | 30 | 7 | 153.62 | 152.22 | 7.28 ± 0.03 | 610.0 ± 35.4 | 4762.5 ± 53.0 | 49.32 ± 0.39 | 0.010 |
1 | 13.18 | 7 | 102.80 | 106.79 | 7.29 ± 0.08 | 455.0 ± 17.0 | 3262.5 ± 159.1 | 16.33 ± 2.10 | 0.005 |
1 | 46.82 | 7 | 170.00 | 169.61 | 7.50 ± 0.05 | 901.5 ± 24.8 | 8562.5 ± 123.7 | 58.18 ± 5.15 | 0.007 |
1 | 30 | 5.32 | 77.59 | 91.56 | 6.66 ± 0.05 | 973.5 ± 7.8 | 3175.0 ± 70.7 | 118.24 ± 4.29 | 0.037 |
1 | 30 | 8.68 | 140.59 | 130.22 | 7.60 ± 0.01 | 820.0 ± 14.1 | 8112.5 ± 123.7 | 24.88 ± 1.77 | 0.003 |
1 | 30 | 7 | 168.33 | 168.60 | 7.40 ± 0.01 | 781.5 ± 27.6 | 5912.5 ± 53.0 | 28.46 ± 2.31 | 0.005 |
1 | 30 | 7 | 160.02 | 168.60 | 7.42 ± 0.01 | 807.5 ± 31.8 | 5725.0 ± 106.1 | 30.67 ± 1.68 | 0.005 |
1 | 30 | 7 | 175.53 | 168.60 | 7.38 ± 0.06 | 824.0 ± 29.7 | 5900.0 ± 106.1 | 27.88 ± 1.92 | 0.005 |
1 | 30 | 7 | 178.15 | 168.60 | 7.33 ± 0.07 | 789.0 ± 34.0 | 5862.5 ± 123.7 | 25.64 ± 0.69 | 0.004 |
1 | 30 | 7 | 162.53 | 168.60 | 7.43 ± 0.04 | 780.0 ± 22.6 | 6425.0 ± 141.4 | 30.17 ± 1.90 | 0.005 |
1 | 30 | 7 | 167.65 | 168.60 | 7.41 ± 0.06 | 824.0 ± 11.3 | 5862.5 ± 88.4 | 31.20 ± 0.53 | 0.005 |