Microalgal suspensions | Contact angles (°) | Surface tension parameters and free energy of hydrophobic interaction (mJ m −2 ) | Zeta potential (mV) | ||||||
---|---|---|---|---|---|---|---|---|---|
θ W | θ B | θ F | \( {\boldsymbol{\gamma}}_{\boldsymbol{s}}^{\mathbf{LW}} \) | \( {\boldsymbol{\gamma}}_{\boldsymbol{s}}^{\mathbf{AB}} \) | \( {\boldsymbol{\gamma}}_{\boldsymbol{s}}^{-} \) | \( {\boldsymbol{\gamma}}_{\boldsymbol{s}}^{+} \) | \( \varDelta {\boldsymbol{G}}_{\boldsymbol{sws}}^{\mathbf{TOT}} \) | ||
Single cultures | |||||||||
C. vulgaris | 46.5 ± 2.8 a | 37.1 ± 1.5 a | 61.0 ± 0.3 a | 35.0 ± 1.5 a | 0.0 ± 0.0 a | 48.7 ± 6.9 a | 0.1 ± 0.1 a | 52.5 ± 14.3 a | −35.4 ± 0.4 a |
M. aeruginosa | 44.8 ± 5.5 a | 37.1 ± 1.6 a | 36.4 ± 8.4 b | 35.9 ± 0.7 a | 10.7 ± 2.8 b | 57.4 ± 7.6 a | 0.5 ± 0.4 a | 43.4 ± 15.5 a | −40.0 ± 2.4 a |
P. subcapitata | 48.7 ± 1.1 a | 37.3 ± 2.2 a | 45.8 ± 3.6 b | 35.8 ± 1.0 a | 5.4 ± 1.5 b | 35.9 ± 1.7 b | 0.2 ± 0.2 a | 13.8 ± 3.8 b | −48.1 ± 0.9 b |
S. salina | 51.9 ± 8.0 a | 37.3 ± 1.0 a | 73.6 ± 1.1 a | 35.8 ± 0.4 a | 0.0 ± 0.0 a | 22.6 ± 3.2 b | 0.0 ± 0.0 a | −10.2 ± 6.6 b | −43.1 ± 2.4 b |
Mixed cultures | |||||||||
C. vulgaris + M. aeruginosa | 41.9 ± 2.8 a | 34.2 ± 4.4 a | 51.6 ± 3.6 c | 37.0 ± 1.8 a | 0.5 ± 0.3 a | 53.0 ± 8.9 a | 0.0 ± 0.0 a | 40.6 ± 11.8 a | −35.4 ± 1.0 a |
C. vulgaris + S. salina | 76.8 ± 4.2 b | 35.3 ± 2.1 a | 57.0 ± 3.1 c | 36.6 ± 0.8 a | 0.0 ± 0.0 a | 52.2 ± 1.5 a | 0.0 ± 0.0 a | 40.1 ± 2.5 a | −45.1 ± 1.4 b |
P. subcapitata + M. aeruginosa | 41.9 ± 2.8 a | 37.3 ± 0.9 a | 35.5 ± 1.5 d | 35.8 ± 0.4 a | 11.7 ± 0.8 b | 37.0 ± 4.8 b | 0.9 ± 0.3 a | 13.4 ± 7.2 b | −42.7 ± 1.4 b |
C. vulgaris + P. subcapitata | 57.0 ± 0.1 a | 39.6 ± 0.1 a | 56.0 ± 0.2 c | 34.0 ± 0.1 a | 0.0 ± 0.0 a | 32.7 ± 0.3 b | 0.0 ± 0.0 a | 10.5 ± 0.5 b | −42.7 ± 1.5 b |
P. subcapitata + S. salina | 54.2 ± 1.9 a | 37.6 ± 0.3 a | 50.7 ± 1.1 c | 35.6 ± 0.1 a | 2.8 ± 0.5 c | 32.0 ± 1.9 b | 0.1 ± 0.0 a | 8.3 ± 3.3 b | −40.5 ± 0.5 b |
S. salina + M. aeruginosa | 93.5 ± 3.3 c | 35.0 ± 3.2 a | 84.0 ± 1.3 a | 36.7 ± 1.3 a | 0.0 ± 0.0 a | 7.6 ± 2.2 c | 0.0 ± 0.0 a | −50.4 ± 8.6 c | −34.9 ± 1.0 a |