Sequential Thermophilic Anaerobic and Aerobic (Ana/Aer) Digestion for Enhanced Solids and Nitrogen Removal
A sewage sludge digestion system consisting of anaerobic (ANA) digestion followed by aerobic (AER) digestion step was studied to determine the impact on solid and nitrogen removal. It was found that the combined ANA/AER system provided higher solid and ammonia removal compared to conventional single ANA digestion with a 32 day SRT. In this study, an efficient Total Solid (TS) and Total Kjeldahl Nitrogen (TKN) removal in ANA/AER system was measured higher compared to single AN system. In ANA/AER system, TS and TOC reduction rates were observed 29 and 32%, respectively, while the TKN removal increases to 50%. This finding shows ANA/AER system as an alternativetechnologi in wastewater treatment.
Index Terms - anaerobic digestion, aerobic digestion, nitrogen removal, sludge treatment, solid removal