International Journal of Waste Resources

Abstract

Technologies Used in the Wastewater Treatment for Nutrient Removal

Margarida Marchetto

In this paper will be showed some techniques employed effectively in wastewater treatment for nutrient removal. The results concerning biological phosphorus and nitrogen removal, from an anaerobic expanded bed reactor (AEBR), treating domestic wastewater, in an Intermittent Aeration Reactor (IAR) followed by dissolved air flotation (DAF); aiming to remove chemical oxygen demand (COD), nitrogen and phosphorus on the same unit. The DAF was used for separation of suspended solids. Conditions to obtain nitrification were assessed, denitrification and phosphorus removal in a reactor operated with alternate aerobic and anaerobic periods. The intermittent aeration system was operated with hydraulic detention time (θh) of 8 hour and 6 hours. The system with intermittent aeration (θh:6hr) showed stable results and presented average COD removal of 92% (90 to 94%) and average phosphorus removal of 90% (82 to 96%). For hour detention time, the average orthophosphate (PO4 -3-P) removal was: 84% (60 to 94%) for raw samples and 94% (60 to 98%) for filtered samples (filter: 0.45 µm). Neither the use of the external carbon source nor pH correction was necessary.