Synthesis of biopolyesters by microorganisms in activated sludge

Abstract

This chapter discusses polyhydroxyalkanoate (PHA) production using microorganisms in activated sludge. PHAs are biopolyesters produced by prokaryotic microorganisms. They are environment friendly, completely biodegradable thermoplastic, and are produced from renewable resources. PHA content must be increased to minimize the cost of PHA production. Applying different acclimatization method and different conditions for PHA production can increase PHA content. To achieve higher PHA content, a side stream reactor for PHA production is beneficial; that is, the process is divided into two reactors: the PHA accumulating bacteria enrichment reactor (PABER), and the PHA production reactor (PPR). PHA is produced by activated sludge because by using activated sludge, waste organic materials in solid wastes or wastewaters are recovered and reused as biodegradable plastics and the cost of PHA production is reduced. PHA is accumulated by anaerobic–aerobic activated sludge under both anaerobic, as well as aerobic conditions. The chapter concludes that organic compounds in wastewater are regarded as pollutants and are removed from water in forms, such as carbon dioxide or waste sludge.