Removal of ammonium nitrogen and orthophosphate from urban wastewater by stabilized microalgae cells

Provision of useful strategies and targeted plans in order to reduce the consumption of available water resources and also create good quality wastewater is necessary due to current lack of water resources. This study was carried out to investigate the removal of ammonium nitrogen and orthophosphate from urban wastewater using two microalgae strains.
Material & For this purpose cultured cells of Chlorella and Oocystis were mixed up with 4% sodium alginate solution. The resulting mixture was added to a solution of calcium chloride in order to form alginate globules containing microalgae cells. To measure cell growth, Neubauer Chamber counting method was used. The amount of nitrogen and orthophosphate removal was measured by light absorption method using Nessler's and Armstrong’s reagents, respectively.
Oocystis removed about 65.2 % of the ammonium nitrogen following 14 days of treatment. Moreover, the overall efficiency of the orthophosphate removal was 69 %. In case of Chlorella, the rate of ammonium nitrogen removal was 74.3 % following 4 days of treatment and reached 100% following 7 days of treatment. The overall orthophosphate removal efficiency was 62.27 %.
The results indicated that Chlorella has the convenient ability to remove nitrogen and phosphorus from wastewater in designed conditions.