The Recovery and Synthesis of Polyhydroxyalkanoates in the Process of Nitrogen and Phosphorus Removal in Low-Carbon Sewage Based on pH and Nitrogen and Phosphorus Restriction Under Anaerobic-Oxygen Limited Process
Abstract Polyhydroxyalkanoate (PHA) is a new type of bio-polyester which is expected to replace traditional petroleum-based plastics. It is also a critical transformation hub of carbon source in nitrogen and phosphorus removal in sewage. Based on the anaerobic-oxygen limited process, the experiment took organic solid waste fermentation liquid as carbon source control hub and realized PHA synthesis and recovery in denitrification and phosphorus removal from low carbon sewage the SBR reactor by regulating pH value and nitrogen and phosphorus restriction. The experimental results showed that when the ratio of C/N and C/P was 150, the content of PHA accounted for 50.39% and 36.07 of the dry cell weight, respectively. Besides, it was found that increasing the C/N ratio was beneficial to increasing the proportion of PHV in PHA. This study proved the feasibility of using an anaerobic-oxygen limited process to recover PHA in nitrogen and phosphorus removal from low-carbon sewage, which saves gas and reduces energy consumption. At the same time, it also provides some help for the follow-up study of low-carbon urban sewage nitrogen and phosphorus removal coupled with resource recovery of PHA to guide the water industry economy to develop in a circular and sustainable direction