Algae in the Assessment of Industrial Wastewater Holding Ponds

The ecology and photosynthetic behaviour of the microalgalcommunity in an oil refinery wastewater holding pond was studiedwith a view to assess the role of algae in industrial effluenttreatment ponds. The biological and physico-chemical parameterswere measured for one year from February 1994 to February 1995.The assessment of algal population based on chlorophyll andprimary productivity revealed that the pond is a eutrophic systemsupporting continuous algal bloom. There was no significantcorrelation between the algal biomass and the nutrient parameterstested. A comparison of the algal gross primary production andthe community respiration for the period was done to assess thedegree of waste stabilisation, and it was found that the pondwater is of eutrophic potential. Bioassays of the effluent usingpure cultures of algae, Chlorella pyrenoidosa, Oocystispusilla and Oscillatoria quadripunctulata again confirmedthat the effluent is stimulatory to algal growth. Thus thestudy of algal community in the field surveys and the algalbioassays of the effluent, established that algae can be used asan effective tool to assess the degree of stabilisation of industrial effluents.