Characteristic of high temperature fermentation for ammonia production

Abstract

This study investigated ammonia production and recovery under high temperature conditions. A reactor with a working volume of 2.0 L was fed with synthetic wastewater, and then the temperature was increased at 1 °C d⁻¹ at HRT (Hydraulic Retention Time) of 4 days. The effects of sludge return, temperature (50–80 °C), HRT (4–10 days) and influent TS (Total Solids) levels (3.02–4.83%) on ammonia fermentation were studied in this work. In the ammonia production phase, the maximum ammonia concentration was obtained for runs with the sludge return method at 72 °C. With increased HRT and influent TS up to 4.23%, the ammonia concentration was increased. The ammonia stripping flow rate ranged from 0.10 to 0.25 L L⁻¹ min⁻¹. With an increased flow rate, the ammonia removal efficiency was increased. In this study, if all of the removed ammonia was recovered, 0.431 L d⁻¹ liquid ammonia would be achieved.