The treatment of high nitrogen and phosphorus containing wastewater by the sequential anaerobic - photo bioreactor membrane systems

The Treatment of High Nitrogen and Phosphorus Containing Wastewater by the Sequential Anaerobic - Photo Bioreactor Membrane Systems This work aims to determine the possibility of growing and nutrient removal capacities in wastewater lipid containing microalgae Chlorella vulgaris (C. vulgaris) as a potential candidate for biodiesel production. For these purpose microalgae were cultivated in a submerged membrane photo-bioreactor (SMPBR) with anaerobic membrane bioreactor (SAnMBR) effluent at 12,000 Lux of light intensity, with a 12 h period of daily light and sterilized aeration. In this study, the growth performance of C. vulgaris was determined in the laboratory with SAnMBR effluents. Nutrient removal efficiencies of both SAnMBR and SMPBR systems were also investigated. All of the experiments for SMPBR and SAnMBR were continued under the continuous flow. Trials were done for a period of 18 days in the laboratory at average 25 0C for SMPBR and 37 0C for SAnMBR. Under these conditions, the experimental results showed that by the end of 18-day continuous studies, SAnMBR could remove ammonium, total nitrogen, total phosphorus, and total organic carbon (TOC) by removal percentages of 7,58–55,89%, 14,35–31,38%, 1.80–19,44% ve 96,35–98,78% respectively from high nitrogen and phosphorus containing synthetic wastewater. The results also showed that by the end of 18-day continuous studies, SMPBR could remove ammonium, total nitrogen, total phosphorus, and total organic carbon (TOC) by removal percentages of 27,88–67,52%, 23,29–88,29%, 0,45–24.74% ve 6,08-51,93% respectively from SAnMBR effluent wastewater. The results also showed that the integrated system, could remove ammonium, total phosphorus, and total organic carbon (TOC) by 34,14–81,52%, 38,27–90,67%, 7,41–26,85% ve 97,19–98,89% respectively from strong wastewaters. According to our findings, Chlorella vulgaris contains significant amounts of lipid for biodiesel production. At the same time high nutrient removal from wastewater is provided. For this reasons, Chlorella vulgaris can be used for the tertiary treatment of wastewater and for biodiesel production. Key words: Wastewater, Chlorella vulgaris, microalgae, tertiary treatment, nutrient removal.