Table 2 COD, TN, and P removal efficiencies and CH₄ concentration in the upgraded biogas during the operational period evaluated.

Mono-cultivation of microalgae (cultures 1)

Chlorella vulgaris

68.93^a ± 4.28

65.29^b ± 5.34

64.39^a ± 4.76

83.69^a ± 5.31

Scenedesmus obliquus

70.27^a ± 5.03

69.37^a ± 4.83

62.55^a ± 5.08

85.03^a ± 3.28

Selenastrum capricornutum

61.04^b ± 3.97

59.74^c ± 5.27

57.33^b ± 5.15

80.56^b ± 4.74

Nitzschia palea

67.89^a ± 5.31

67.86^ab ± 4.96

61.29^a ± 4.67

84.36^a ± 4.57

Anabaena spiroides

63.75^b ± 4.85

61.38^c ± 5.39

56.11^b ± 4.03

79.35^b ± 3.73

Co-cultivation of microalgae with fungi (cultures 2)

Chlorella vulgaris

73.85^ab ± 5.11

71.09^ab ± 6.34

70.47^a ± 5.62

89.78^a ± 3.09

Scenedesmus obliquus

75.67^a ± 5.78

74.57^a ± 5.87

68.39 ^ab ± 4.39

90.35^a ± 3.77

Selenastrum capricornutum

67.59^bc ± 4.36

64.18^c ± 4.39

59.88^c ± 3.97

85.17^b ± 2.78

Nitzschia palea

70.36^b ± 6.09

69.66^b ± 5.21

66.26^b ± 5.79

88.39^a ± 3.25

Anabaena spiroides

65.18^c ± 4.65

63.37^c ± 4.98

61.93^c ± 4.31

84.39^b ± 3.89

Co-cultivation of microalgae with activated sludge (cultures 3)

Chlorella vulgaris

70.82^ab ± 4.73

75.26^ab ± 6.32

68.73^a ± 5.57

87.37^ab ± 4.83

Scenedesmus obliquus

71.76^a ± 5.71

76.44^a ± 5.93

67.24^a ± 4.39

90.79^a ± 3.11

Selenastrum capricornutum

67.37^b ± 5.06

70.69^c ± 5.38

62.36^b ± 5.32

88.68^ab ± 3.27

Nitzschia palea

72.32^a ± 5.47

73.43^bc ± 4.65

65.67^ab ± 4.08

91.06^a ± 2.88

Anabaena spiroides

64.38^c ±4.58

69.08^c ± 5.17

62.44^b ± 5.43

83.83^c ± 3.31