Publications in Scientific Journals:
L. Jahn, T. Baumgartner, K. Svardal, J. Krampe:
"The influence of temperature and SRT on high-solid digestion of municipal sewage sludge";
Water Science and Technology,
The influence of temperature and solids retention time (SRT) on high-solid digestion of municipal sewage sludge was investigated in laboratory-scale reactors. Digestion with high-solid concentration reduces the required digestion volume and is advantageous for urban areas. The experimental conditions comprised total suspended solids (TSS) in digested sludge between 4.0 and 4.6%, temperatures in a range of 33 to 41 oC and the SRT between 10 and 25 d. High-solid Digestion operates with increased NH4-N concentrations released from organic compounds. The anaerobic process can be limited by high NH4-N concentration and toxic NH3. In this study a stable digestion was observed up to 2,000 mg L-1 NH4-N and 75 mg L-1 NH3. Volatile suspended solids (VSS) and chemical oxygen demand removal was 53% and 57% respectively. However, digestion with 10 d SRT led to a declined VSS removal of 49%. The removal at 41 and 37 oC showed minor differences, while reduced NH4-N release and reduced methane production were observed at 33 oC. For economic reasons, high-solid digestion at 41 oC is not recommended, but will not impair VSS removal. The outcomes of this study confirm that digestion with up to 7.8% TSS in the feed is feasible for the tested temperatures and SRT down to 15 d.
ammonia inhibition, high-solid concentration, mesophilic digestion, methane
"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)
Created from the Publication Database of the Vienna University of Technology.