Abstract
In this investigation, the anaerobic digestion (AD)
results from different substrates were evaluated. By means of
two co-digestion processes with cow dung, it was observed a
good performance in the first process and a poor production
trend in the second one. NaOH was used as chemical absorbent
in two different bottles in the CO2 fixing unit to compare the
volume of biomethane produced. A batch anaerobic codigestion
was carried out in 500 mL digesters which were
placed into a water bath at 45°C and maintained at the initial
pH of 7. Important AD factors such as pH, Carbon and
Nitrogen ratio (C/N), concentration, substrate composition
were observed. Through an ultimate analysis, amount of
Carbon (C), Hydrogen (H), Nitrogen (N), and Sulphur (S) were
also discussed. The toxicity of other elements found in
substrates appeared higher in the second process than in the
first. It was concluded that inhibitory elements identification
and control before furthering any biogas production process
were primordial.