Removal of Organochlorine Compounds in an Upflow Flocculated Algae Photobioreactor

An upflow alum-flocculated algae photobioreactor was investigated for removal of toxic chlorinated organic compounds, chlorobenzene and 2,4-dichlorophenol. Biodegradation was evaluated by monitoring substrate disappearance and concurrent generation of artifacts. Chlorobenzene disappeared faster than 2,4-dichlorophenol. Relative rates of removal were greater by the live than by the dead algae biomass. In this study, gravity-concentrated, suspension-centrifuged, and alum-flocculated algae biomass cultures of Chlorella and Scenedesmus were used. In batch and continuous upflow photobioreactor experiments to treat wastewaters containing 50, 100, 200 (batch), and 1,000 mg/l (continuous) each of chlorobenzene and 2,4-dichlorophenol were applied to the bioreactors individually and also as a mixture. The continuous upflow photobioreactor system was found to be efficient, versatile, adaptable and easy to operate for removal and biodegradation of these organochlorine compounds.