A review on the use and applications of volatile fatty acids on faecal sludge sanitization

Basic sanitation is still lacking in many developing countries, resulting in significant environmental health risks. The efficient disposal of food waste with potential resource recovery has recently gained much attention. Food waste is considered to be a favourable substrate for the anaerobic digestion (AD) because it has easy biodegradability, rich nutrient availability, and high water content. Waste disposal as well as energy recovery can be achieved through AD of food waste. Volatile fatty acids (VFAs) are among the essential intermediates produced when organic waste is treated in the AD process. They are produced during the acidogenesis and acetogenesis stages of AD. VFA is an important substrate for the microorganisms that are involved in the production of biodegradable plastics, bioenergy, nutrient removal processes, and the inactivation of pathogens. Since the degree of acidification and the key metabolic pathways during fermentation are influenced by the characteristics of the substrate, the amount and composition of VFAs obtained during the AD process may vary depending on the substrate used. This article reviews the achievements and applications of VFAs to inactivate pathogens.