The synthesis of polyhydroxyalkanoates from low carbon wastewater under anaerobic-microaerobic process: effects of pH and nitrogen and phosphorus limitation

Polyhydroxyalkanoate (PHA) is a new type of bio-polyester which expected to replace traditional petroleum-based plastics. The experiment was carried out based on anaerobic-microaerobic process. Firstly, the PHA accumulation capacity activated sludge under different pH conditions discussed, and then batch test nitrogen phosphorus limitation condition optimal pH. Moreover, content monomer nutrient restriction also studied. experimental results showed that when not controlled (7.5~8.5), C:N C:P weight ratio equal 150, maximum accounted for 50.39% 36.07% dry cell weight, respectively. Besides, it found increasing beneficial proportion polyhydroxyvalerate (PHV) in PHA.