Growth and Removal of Nitrogen and Phosphorus by a Macroalgae Cladophora glomerata under Different Nitrate Concentrations

Abstract

Effectiveness of macroalgae was investigated for enhancing wastewater treatment processes. Bioremediation using macroalgae could remove nitrate and phosphate contaminants in the water where algae assimilate nitrogen and phosphorus and convert them to biomass. This study evaluates the effects of high nitrate concentration on the kinetics of cell growth during nitrate and phosphate removal by a macroalga Cladophora glomerata. The algal growth and nitrate removal from media containing initial nitrate concentrations of 5mg/L to 400 mg/L were monitored in batch growth, whereas control media has no additional nitrate. Light exposure was kept for 12 and 20 hours. The purpose of this research was to find out the effect of various nitrate concentrations on nitrate and phosphate removal with macroalgal growth. Maximum growth kinetic reaches μ=0.075/day in 20 hours light exposure with 100 mg/L initial nitrate concentration. Nitrate and phosphate reach about 90% removal rates on the fifth day. Nitrate concentration was not significantly affected by biomass growth (Pearson correlation: 0.295). But, phosphate concentration has a moderate correlation with macroalgae biomass (Pearson correlation: 0.533).