Algal biomass production in digested palm oil mill effluent

Abstract

The average gross biomass productivities of algal ponds for the secondary treatment of palm oil mill effluent compared favourably with results from reported algal production systems. A three-stage, overflowing pond-system, with 1 m2 fibreglass tanks and total pond volumes of 100 litres, was used. The average gross biomass productivities ranged from 5·01 to 15·41 g m-2 day-1 (calculated from chlorophyll-a content). Gross biomass productivities decreased with increasing retention time of the ponds. While actual yields in the ponds were found to be much below the theoretical values, carbon, nitrogen and phosphorus were not found to be limiting. Light is the limiting factor, because it is rapidly absorbed by the high solids content of the effluent. Chlorella dominated at low organic loading rates while Phacus and Euglena were abundant at high organic loading rates. © 1988.