| Abstract: | Cyanophyta was the dominant algal group in the effluents of Mathura Oil Refinery and its relative abundance decreased with the removal of pollutants; the composition of this group, however, never decreased below 60%. Some members of Bacillariophyta and Chlorophyta were also recorded. Among the blue greens, Oscillatoria was the most abundant genus throughout and this is a reflection of the marked capability of this organism to withstand oil pollution. The diversity (d) of the algal community increased owing to the removal of oils and phenols in effluent treatment ponds. No marked seasonal variation in the abundance of various algal taxa and diversity was apparent. Even slight changes in the concentration of oil and phenol from 5.1 to 1.2 mg/l and 1.56 to 0.20 mg/l, respectively, resulted in an appreciable increase in diversity. The study reveals that algal community structural parameters like relative abundance and diversity could be, irrespective of the time of sampling, effectively used for monitoring the quality of effluents in oil refineries. |
