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Table 2 Characteristics of struvite-precipitated supernatant under different NH4+:Mg2+:PO43− molar ratio and pH

From: Cultivation of lipid-producing microalgae in struvite-precipitated liquid digestate for biodiesel production

NH4+:Mg2+:PO43− molar ratio pH NH4+-N (mg/l) NO3-N (mg/l) PO43−-P (mg/l) N:P mass ratio Transmittance (%) Salinity (%) NH4+-N removal rate (%)
1:1:0.95 8.0 142.52 ± 2.10a 0.692 ± 0.021a 35.47 ± 0.48a 4.12 ± 0.68a 70.00 ± 0.76a 0.72 ± 0.21a 81.18 ± 0.37a
8.5 118.71 ± 0.48b 0.771 ± 0.049a 29.87 ± 0.32b 4.05 ± 0.22a 71.12 ± 0.66a 0.69 ± 0.11b 83.33 ± 0.08b
9.0 78.06 ± 0.25c 0.755 ± 0.074a 26.24 ± 0.70c 3.06 ± 0.42b 71.78 ± 0.74a 0.70 ± 0.01ab 86.41 ± 0.04c
1:1:1 8.0 90.07 ± 0.08d 0.030 ± 0.019b 34.12 ± 0.39d 2.70 ± 0.73b 74.65 ± 1.33b 0.67 ± 0.07b 85.32 ± 0.01d
8.5 83.78 ± 0.82e 0.092 ± 0.076b 22.78 ± 0.51e 3.75 ± 0.04b 77.36 ± 1.34b 0.61 ± 0.08b 86.41 ± 0.14c
9.0 66.56 ± 0.52f 0.063 ± 0.048b 16.36 ± 0.07f 4.16 ± 0.23a 74.82 ± 0.86b 0.62 ± 0.08b 88.41 ± 0.09e
1:1.2:1.2 8.0 71.08 ± 1.38 g 0.053 ± 0.032b 18.92 ± 1.52 g 3.86 ± 0.57b 72.19 ± 1.53a 0.64 ± 0.03b 89.62 ± 0.24f
8.5 57.85 ± 0.66 h 0.046 ± 0.042b 8.51 ± 0.84 h 7.04 ± 0.72c 78.28 ± 0.38bc 0.66 ± 0.03b 91.63 ± 0.11 g
9.0 38.95 ± 0.74i 0.071 ± 0.016b 7.02 ± 1.21 h 5.65 ± 0.43d 79.60 ± 0.01d 0.67 ± 0.02b 93.22 ± 0.13 h
  1. Results are expressed as the mean ± SD (n = 3)
  2. a,b,cDifferent letters in the same row indicate significant differences at p < 0.05