Open AccessTwo-Stage Anaerobic Digestion Process Combining Pre-digestion with Methanization
Author(s) -
Mohammed Mohaibes
Publication year - 2015
Publication title -
maǧallaẗ markaz buḥūṯ al-taqniyyaẗ al-aḥyāʾiyyaẗ
Language(s) - English
Resource type - Journals
eISSN - 2708-1370
pISSN - 1815-1140
DOI - 10.24126/jobrc.2015.9.2.436
Subject(s) - anaerobic digestion , digestion (alchemy) , biogas , mesophile , sewage sludge , manure , chemistry , clostridium perfringens , yield (engineering) , pulp and paper industry , food science , methane , sewage treatment , zoology , biology , agronomy , chromatography , environmental science , environmental engineering , bacteria , materials science , organic chemistry , ecology , genetics , metallurgy , engineering
Anaerobic digestion of a mixture of manure and sewage sludge by combination of the biological predigestion at 73°C with methanization at 55°C was studied with regard to the biogas process efficiency,energy balance and sanitation effect. Performance of the two-stage digestion was compared with theconventional, one-stage moderate thermophilic digestion at 55°C and mesophilic digestion at 37°C,respectively. The best performance was achieved by the two-stage treatment both in terms of VolatileSolids (VS) removal and biogas yield. Up to 60% of VS was removed and a specific methane yield of 300ml CH4 gVS-1 was achieved. Sanitation effect was measured as inactivation of the indicators of bacterialpathogens - the faecal enterococci and spores of Clostridium perfringens. Elimination of faecal enterococcito non-detectable level occurred only during treatments at 73°C and 55°C. Numbers of Clostridiumperfringens spores were reduced solely by the combined 73°C/55°C treatment.