Acids (VFAs) and bioplastic (PHA) recovery

The increase of population and industrialization has led to the scarcity of resources, so sustainable wastewater treatment technologies with resources recovery, such as volatile fatty acids (VFAs) or bioplastics (e.g., polyhydroxyalkanoates (PHA)) to comply with the circular economy concept and as an alternative to the conventional methods are of the utmost importance and could help to achieve a net-zero impact in wastewater treatment plants. VFAs are a valuable resource with a wide range of applications and with an increasing market demand. VFA can be produced from wastewaters through acidogenic fermentation and recovered by several physicochemical methods. PHA polymers, another valuable product, are intercellular energy and carbon reserves of organisms that can be recovered. They have similar properties to the conventional plastics and can be used in diverse application areas. This chapter reviews the production of VFAs and PHA from wastewater using mixed microbial cultures-based processes, as well as their recovery and main applications.