Study on efficiency of nitrogen and phosphorus removal by algal biofilm

Cultivating algal biofilm on nitrogen (N) and phosphorus (P) in waters presents an alternative to control eutrophication. Under laboratory conditions, efficiency on nitrogen and phosphorus removal from synthetic wastewater, secondary effluent and eutrophic lake water by algal biofilm was assessed. Algal biofilm was mainly composed of blue-green algal species Oscillatoria princeps. During a 5-day treatment, for synthetic wastewater, secondary effluent and eutrophic lake water, removal rates of TN were 57.1 %, 94.5 % and 93.8%, respectively, removal rates of TP were 93 %, 73 % and 79 %, respectively. The dried algal production were 3. 7 similar to 7. 2 g center dot m(-2) center dot d(-1) and the TKN and TP of algal biomass were 5.7% similar to 7.2% and 0.78% similar to 2.44 %, respectively. Recovery of nutrients in harvested algal biomass accounted for about 20% similar to 39 % for N and 65% similar to 82% for P