Investigation of Immobilization of Microalgae Chlamydomonas for Orthophosphate Removal from Municipal Wastewater

The aim of this research is to study the performance of microalgae Chlamydomonas in orthophosphate removal from municipal wastewater. In this research three treatments in three replications were applied. The treatments were free and immobilized cells of Chlamydomonas in alginate and blank (without microalgae). Three treatments were added into bioreactors with different rate of aeration (0, 1 and 2.5 Lmin-1), containing 1.5 litre of secondary effluent of Shiraz wastewater treatment plant. Orthophosphate removal from wastewater was examined for 14 days. The highest orthophosphate removal rate (10.33 percent per day) belonged to the immobilized microalgae treatment with 2.5 Lmin-1 aeration rate. Furthermore, for the immobilized microalgae treatments, removal efficiency decreased as a result of decrease in aeration rate. The results of free Chlamydomonas with 1 Lmin-1 aeration rate in orthophosohate removal were remarkable. Immobilization of microalgae with increasing aeration rate would improve algal- bacterial process and also would increase efficiency of orthophosphate removal