By analyzing the concentration changes of nitrogen and phosphorus in experimental water

both a laboratory study and an outdoor experiment have been conducted for testing the removal efficiency of nutrients by algae.The test alga for the laboratory study is Chlorococcum sp.and for the field experiment is Cladophora oligoclona Kütz.respectively.The results show that Chlorococcum sp.grow quite well and have high removal rates of nitrogen and phosphorus in the sewage with very high concentrations of nitrogen and phosphorus.The removal rates of total soluble nitrogen

nitrate

ammonia and total soluble phosphorus from synthetic sewage were 46.2%

37.8%

98.4% and 79.3% in six days.The removal rate of total soluble phosphorus from crude lake water by the alga was 79.2% in five days.Cladophora oligoclona can grow normally and absorb relatively on nitrogen and phosphorus from the natural water in outdoor conditions.It plays an important role on reducing the specific conductance and improving the water quality.According to the results obtained in this study and referring to other relational research reports

both Chlorococcum sp.and Cladophora oligoclona have ability for removing nutrients from wastewater.Chlorococcum sp.is suitable for rehabbing and improving in static water and Cladophora oligoclona is suitable for treating and protecting in flowing water.