Nitrification, denitrification and biological phosphorus removal in piggery wastewater using a sequencing batch reactor

Nutrients in piggery wastewater with high organic matter, nitrogen (N) and phosphorus (P) content were biologically removed in a sequencing batch reactor (SBR) with anaerobic, aerobic and anoxic stages.The SBR was operated with 3 cycles/day, temperature 30 °C, sludge retention time (SRT) 1 day and hydraulic retention time (HRT) 11 days. With a wastewater containing 1500 mg/l ammonium and 144 mg/l phosphate, a removal efficiency of 99.7% for nitrogen and 97.3% for phosphate was obtained.Experiments set up to evaluate the effect of temperature on the process showed that it should be run at temperatures higher than 16 °C to obtain good removals (<f>></f>95%).Batch tests (ammonia utilization rate, nitrogen utilization rate and oxygen utilization rate) proved to be good tools to evaluate heterotrophic and autotrophic biomass activity.The SBR proved to be a very flexible tool, and was particularly suitable for the treatment of piggery wastewater, characterized by high nutrient content and by frequent changes in composition and therefore affecting process conditions. [Copyright &y& Elsevier]