Figure 8: Absorption spectra of filterate of Chlorella vulgaris grown on 60 mg.L-1 of anthracene (A), 40 mg.L-1 of naphthalene (B), Elkatothrix viridis 60 mg.L-1of anthracene (C), 40 mg.L-1 of naphthalene (D) ( _______ ) Standard (---------- ) after 3 days of incubation.