Novel insight into the process of nutrients removal using an algal biofilm: The evaluation of mechanism and efficiency.

Eutrophication of water by nutrient pollution remains an important environmental issue. The aim of this study was to evaluate the nutrient uptake capacity of an algal biofilm as a means to treat polluted water. In addition, the study investigated the nutrient removal process. The algal biofilm was able to remove 99% of phosphorus within 24 hours of P addition, with the PO-P concentration in inflowing water ranging from 3 to 10 mg L. Different patterns of phosphorus and nitrogen removal were observed. Daily quantity of removed NO-N ranged from 2 to 25% and was highly dependent on solar irradiance. Precipitation of phosphorus during the removal process was studied using X-ray diffraction analyses and was not confirmed in the biofilm. The biofilm system we constructed has a high efficiency for phosphorus removal and, therefore, has great potential for integration into wastewater treatment processes.