Optimization of activated sludge recycling and oxidized ammonium recycling as odour control strategies in wastewater treatment plants

New odour prevention strategies in wastewater treatment facilities need to be investigated find effective and low-cost technologies for the control of malodorous emissions. In this study, potential activated sludge (AS) oxidized nitrogen (N-NOx) recycling as an environmentally-friendly cost-effective strategy minimization nuisance during was evaluated optimized using H2S, acetic acid α-pinene model odorants 2.1 L gas tight bottles. This approach uses by-products from mitigate annoyance. Preliminary abiotic tests showed headspace concentration losses 25% H2S α-pinene, 7% due odorant adsorption 4 h. The experiments carried out at different concentrations AS (0, 10, 25, 50, 100 mg VSS/L) (1.5, 5, 7.5 10 N-NOx/L) revealed removal 7.5–10 N-NOx/L 50–100 VSS/L. Interestingly, NO3− more than NO2− electron acceptor biodegradation regardless N-NOx concentrations. presence dissolved VSS/L, partially metabolized by microorganisms end experiment (from 27 23 ppmv 4.5 h), while experienced a similar gradual decrease tests. Finally, assays ≥5 NO3−/L 25 VSS/L reduction correlated with biological oxidation which suggested supply under sulphur limiting conditions prevent toxicity problems treatment.