A review of the production and applications of waste-derived volatile fatty acids

• Different types of wastes used for VFA production are reviewed.
• Important factors influencing VFA production performances are detailed.
• Various applications of waste-derived VFA are examined.
• Effects of VFA chain-length on the performances of the applications are elucidated.
• Future research needs of microbial VFA production are proposed.

Low cost production of volatile fatty acids (VFA) from waste by acidogenic fermentation has drawn extensive research interests as VFA is a critical substrate for microorganisms involved in the production of biodegradable plastics and bioenergy, as well as those in biological nutrient removal processes. This article reviews the various wastes amenable to VFA production, the pertinent factors influencing the VFA production, and the various applications of the resulting VFA. In addition to the usual need for reasonably high concentration, a key feature for many applications is the distribution of the chain length of the VFA. Means to regulate these performance indicators are surveyed and discussed in detail.