Spirulina cultivation in digested sago starch factory wastewater

Wastewater arising from the production of sago starchhas a high carbon to nitrogen ratio, which is improvedwith anaerobic fermentation in an upflow packed beddigester. The digested effluent with an average C: N:P ratio of 24: 0.14: 1 supported growth of Spirulina platensis (Arthrospira) with anaverage specific growth rate () of 0.51day^-1 compared with the average of 0.54day^-1 in the inorganic Kosaric Medium in a highrate algal pond. Supplementation with 6 mM urea and2.1 mM K₂HPO₄ produced gross biomassproductivity of 14.4 g m^-2 day^-1. Aflow-rate of 24 cm s^-1 increased the andgross biomass productivity (18 g m^-2 day^-1). The highest crude protein, carbohydrate and lipidcontents of the biomass were 68%, 23% and 11%,respectively. Percentage reductions in chemicaloxygen demand, ammoniacal-nitrogen and phosphatelevels of the digested effluent reached 98.0%, 99.9%and 99.4% respectively. The HRAP offers a goodtreatment system for sago starch factory wastewater.