Determination of Nitrogen and Phosphorus Partitioning within Components of the Biomass in a High Rate Algal Pond: Significance for the Coastal Environment of the Treated Effluent Discharge

Two High-Rate Algal Ponds were operated over residence times of 4 and 6 days respectively, at three COD loading rates equivalent to 600, 350 and 100 kg ha⁻¹d⁻¹ from early September to late October 1991. Samples of pond N and P feed were analysed to obtain nutrient input values to the system. Pond filtrates were also analysed for soluble nutrients. The pond biomass was separated into constituent components of algae and bacteria. Following separation, the discrete fractions were analysed for dry matter, chlorophyll content, and paniculate carbon, hydrogen, nitrogen and phosphorus. Nitrogen and phosphorus balances were then calculated which were used to partition the nutrients into soluble and paniculate phases, and to further separate the paniculate phase into algal and bacterial components. The partitioning of these nutrients, responsible for eutrophication, enables the calculation of removal rates of N and P from the pond systems and makes possible more effective strategies for the removal of the nutrient-rich biomass from receiving water bodies.