Effects of diferent propionic acid concentration on anaerobic degradation

Abstract

In methanogenic environments, propionate is an important intermediate product which is a volatile fatty acids (VFA). Degradation of propionic acid is difficult as they tend to accumulate during anaerobic digestion process. Accumulation of VFA will often result in a drop in pH and at low pH values, VFA will become toxic to the microorganisms and eventually inhibit methanogenesis causing further imbalance to the digestion process which is undesirable. Syntrophic association of acetogens and methanogens are required to degrade VFA. Therefore, there is a need for an essential connection between these two bacteria in order to efficiently degrade VFA. In addition, reports have stated that propionic acid has the slowest degradation rate compared to other VFAs. Hence, this study’s objective is to examine the effect of different concentration of propionic acid on anaerobic digestion.