The quantification of the correlation between water nitrogen level and the phosphorus uptake of Chlorella sorokiniana (freshwater green alga) in simulated nutrient-contaminated freshwater
JEFF LAWRENCE B. DERRAMAS, NINA BEATRIS C. GONZALEZ, TRISTAN TIMOTHY M. VILLAFLOR, and CATHERINE JOY A. MEDIODIA
Philippine Science High School – Western Visayas Campus, Brgy. Bito-on, Jaro, Iloilo City 5000, Department of Science and Technology, Philippines
Eutrophication is a phenomenon wherein there is an oversaturation of nutrients, principally phosphorus and its partner nutrient nitrogen, in an ecosystem. It induces algal blooms which causes water anoxia and overall water quality deterioration. This has become an issue of increasing concern, especially in agricultural countries. Biological removal methods have proven to be cost-effective and efficient against this phenomenon, specifically microalgal bioremediation. Though microalgae have proven to remediate nitrogen and phosphorus, studies that investigate the effect of the presence of nitrogen on phosphorus removal are uncommon. In this study, the correlation between water nitrogen level and the phosphorus uptake of Chlorella sorokiniana, a locally available algae species, was investigated in simulated nutrient-contaminated freshwater. Batch cultures were exposed to treatments of 0, 5, 10, and 15 mg/L of nitrogen and a uniform amount of phosphorus for a period of 11 days, after which the samples were analyzed using UV-vis spectrophotometry. The results showed that a statistically significant positive correlation exists between water nitrogen level and percentage phosphorus removed.
Keywords: Chlorella sorokiniana, eutrophication, limiting nutrients, nitrogen, phosphorus