The influence of oil refinery effluents on the structure of algal communities

Abstract

Gradient analysis of algal communities in the effluents of five oil refineries was done at different stages of wastewater treatment. During the initial stages of treatment Oscillatoria , together with some other forms, was dominant; however, at subsequent stages of treatment, more species appeared corresponding to decrease in pollution load. Maximum number of algal species was nevertheless encountered at the final stages of treatment. The apportionment of individuals belonging to different species and Shannon index also increased as the effluent passed through different stages of treatment. Remarkable similarity has been observed in algal communities growing in the effluents of the refineries studied. The present study suggests that algal communities occurring in refinery effluents can be utilized to predict the prevailing conditions.