Polyhydroxyalkanoate (PHA) production from municipal wastewater and sludge treatment

Wastewater and waste treatment plants, traditionally considered solely as end-of-pipe processes, can be utilised as residuals bio-refineries in which raw wastewater and its organic/inorganic content are transformed into renewable products, such as energy, minerals and chemicals. Polyhydroxyalkanoates (PHA) are a family of completely biodegradable polyesters that can be produced as a novel adjunct to biological wastewater treatment in mixed-microbial activated- sludge systems. PHA have attracted much interest due to their thermoplastic properties and biodegradability. The possibility of producing PHA from renewable resources, especially, from municipal, industrial, and agricultural residuals, has further spurred advancements in biological processes for PHA production. As the opportunities, PHA are recognised as platform chemical raw materials within bio-refinery frameworks. In particular, in the management of wastewaters and solid wastes, PHA production via mixed microbial activated sludge represents an opportunity for recovering raw wastewater organic carbon by means of biological treatment.