Biological phosphorus removal in anaerobic/anoxic sequencing batch reactor

ABSTRACT PhD Thesis BtOLOGlCAL PHOSPHORUS REMOVAL IN ANAEROBİC/ANOXİC SEQUENCING BATCH REACTOR Engin GÜRTEKİN Fırat University Graduate School Natural and Applied Sciences Department of Environmental Engineering 2005, Page : 171 In this study, two anaerobic/anoxic sequencing batch reactors were set up. One from this reactors was feed with acetate. The other reactor was feed with glucose. It was investigated to effect of sludge age, hydraulic retention time and relation among phosphorus release and ratio to carbon uptake of phosphorus release with pH in each reactors. In result of this studies, it was also found to effect of acetate and glucose on biological phosphorus removal in anaerobic/anoxic reactor. In reactor feeding with acetate, efficiency of COD removal was % 94 in sludge time of 20 days, % 93 in sludge time of 15 days, % 90 in sludge time of 10 days and % 89 in sludge time of 5 days. Efficiency of P04-P removal wass % 74 in sludge time of 20 days, % 78 in sludge time of 15 days, % 87 in sludge time of 10 days and % 39 in sludge time of 5 days. It wasn't observed an effect of sludge age on efficiency of COD removal in reactor feeding with acetate. It was found to be optimum of sludge age of 10 days (SET A3) from point of view efficiency of phosphorus removal. In reactor feeding with glucose, efficiency of COD removal was % 92 in sludge time of 20 days, % 91 in sludge time of 15 days, % 91 in sludge time of 10 days and % 90 in sludge time of 5 days. Efficiency of P04-P removal was % 45 in sludge time of 20 days, % 55 in sludge time of 15 days, % 51 in sludge time of 10 days and % 25 in sludge time of 5 days. It wasn't observed an effect of sludge age on efficiency of COD removal in reactor feeding with glucose. It was found to be optimum of sludge age of 15 days (SET G2) from point of view efficiency of phosphorus removal. In reactor feeding with acetate, efficiency of COD removal was % 91 in hydraulic retention time of 12 hours, % 91 in hydraulic retention time of 16 hours, % 92 in hydraulic retention time of 24 hours and % 90 in hydraulic retention time of 8 hours. Efficiency of PO4-P XVremoval was % 87 in hydraulic retention time of 12 hours, % 79 in hydraulic retention time of 16 hours, % 73 in hydraulic retention time of 24 hours and % 79 in hydraulic retention time of 8 hours. It wasn't observed an effect of hydraulic retention time on efficiency of COD removal in reactor feeding with acetate. It was found to be optimum of hydraulic retention time of 12 hours (SET A3) from point of view efficiency of phosphorus removal. In reactor feeding with glucose, efficiency of COD removal was % 91 in hydraulic retention time of 12 hours, % 91 in hydraulic retention time of 16 hours, % 91 in hydraulic retention time of 24 hours and % 90 in hydraulic retention time of 8 hours. Efficiency of P04-P removal was % 55 in hydraulic retention time of 12 hours, % 57 in hydraulic retention time of 16 hours, % 47 in hydraulic retention time of 12 hours and % 33 in hydraulic retention time of 12 hours. It wasn't observed an effect of hydraulic retention time on efficiency of COD removal in reactor feeding with glucose. It was found to be optimum of hydraulic retention time of 16 hours from point of view efficiency of phosphorus removal. It wasn't observed an effect of sludge age and hydraulic retention time on efficiency of NH4-N removal in each reactor. Phosphorus release and uptake increased by increasing from 8 hours to 24 hours of hydraulic retention time in reactor feed with acetate. However, phosphorus removal didn't increase. It was observed decrease at amounts of phosphorus removal, phosphorus release, phosphorus uptake at below and over of hydraulic retention time of 16 hours in case of glucose feeding. It was observed to increasing of phosphorus removal and of ratio to carbon uptake of phosphorus release with increasing of pH at anaerobic phase of each reactor. It was found the effect of acetate and glucose on phosphorus removal by feeding with acetate and glucose into each reactors. It was evaluated efficiencies in reactors investigated effects of both sludge age and hydraulic retention time. It was found that biological phosphorus removal was obtained with glucose. However, phosphorus removal was smaller in comparison with reactor feed acetate. In addition, it was observed to phosphorus release in anaerobic phase and this was balanced with phosphorus uptake. Key Words : Anaerobic/anoxic, biological phosphorus removal, sludge retention time, hydraulic retention time. XVI