STUDY ON THE REMOVAL ABILITY OF NITROGEN AND PHOSPHORUS FROM STIGEOCLONIUM SPP.

In this study, we explored the ability to remove nitrate and phosphorus of two strains of Stigeoclonium spp. (SHY-370 and HB1617) by setting different initial concentrations of ammonia nitrogen and nitrogen/ phosphorus (N/P) ratios in synthetic wastewater. The results indicated that different initial concentrations of ammonia nitrogen in synthetic wastewater could affect the biomass concentration and the ability to remove N and P of SHY-370 and HB1617. The maximum ammonia nitrogen concentration in synthetic wastewater that SHY-370 can tolerate was 10 mg/L, while that was 5 mg/L for HB1617. The ammonia-nitrogen removal rate of SHY-370 and HB1617 was above 97% and the maximum daily ammonia-nitrogen removal rate was 3.98 mg/L/d, while the initial concentration of ammonia nitrogen in synthetic wastewater varied between 1-10 mg/L. N/P ratios had a slight impact on the biomass concentration of the SHY-370, however, the biomass concentration of HB1617 was reduced when the corresponding rate was over 20 mg/L. The concentration of total phosphorus (TP) in synthetic wastewater was 10 mg/L. When the N/P ratio was 2, the content of TP in synthetic wastewater was higher than 10 mg/L, which led to a low TP removal rate. According to the results of our study, we can conclude that SHY-370 and HB1617 are appropriate for the treatment of urban sewage in which the concentration of ammonia nitrogen is relatively low, whereas the concentration of TP and NO₃-N is relatively high.