Polyhydroxyalkanoate Production from Sequencing Batch Reactor System Treating Domestic Wastewater Mixed with Glycerol Waste

The study aimed to determine the polyhydroxyalkanoate (PHA) production and treatment efficiency of sequencing batch reactor (SBR) system treating synthetic domestic wastewater (DW) and synthetic domestic wastewater mixed with glycerol waste (DW+GW). The system with a total sequence of 24 h consisted of filling phase (20 min), reaction phase (22 h), settling phase (1 h), and withdrawal phase (40 min). The two-step SBR operation comprised anoxic/aerobic steps of 4/18 h was employed at reaction phase. The system fed with DW+GW produced higher PHA than the system fed with DW. In addition, PHA accumulation in activated sludge obtained from the anoxic step was higher than the aerobic step in which the highest PHA concentration and PHA yield at 1,086.87 mg/L and 61.42% as dry sludge weight, respectively, were attained. The results of treatment efficiency revealed that the anoxic step performed higher removal efficiencies of total kjeldahl nitrogen and total phosphate than the aerobic step, while an opposite result of COD removal efficiency was found.