Microalgal treatment of municipal wastewater has been discussed as a novel strategy for the removal of excess nutrients and metals. Additionally, a number of products can be obtained from the resulting microalgal biomass, including energy products that can be utilized within the treatment plant. However, the effectiveness of these microalgal systems can be significantly affected by the natural biota, which could consequently impact the quality of the wastewater effluent. This study evaluated the performance of two microalgal species in the removal of nutrients from non-sterile, highly concentrated synthetic wastewater. The results showed that monocultures of Scenedesmus sp. AMDD and Chlorella sorokiniana could remove up to 60 % NH4+, and 44 and 35 % PO43-, respectively, in a semi-continuous cultivation mode without negatively affecting effluent quality.