hance the efficiency of anaerobic digestion to improve VFAs production.
Thermophilic anaerobic digestion of sludge (the temperature range is from 40 to 70ć) has been
investigated regularly linking with mesophilic anaerobic digestion (Riau et al., 2010; Ge et al., 2011).
Fewer studies researched on thermophilic anaerobic digestion independently, especially on its production
of VFAs. Furthermore, the optimal operating conditions for maximizing VFAs production from such
process remain undetermined, particularly the optimum temperature of thermophilic anaerobic digestion.