Relation analysis of phosphorus removal and BOD₅ loading using PHB monitoring in A²/O process

In a pilot-scale anaerobic-anoxic-oxic experimental system for municipal wastewater treatment, PHB consumption in an oxic tank and PHB production in an anaerobic tank had been monitored overtime, and relations among PHB consumption/production, phosphorus removal/release and BOD₅ loading had been analyzed. The results indicated that the consumption of PHB was positively related with phosphorus removal, and about 140 mg PHB consumption could result in 1 mg P removal. In the anaerobic tank, about 1.17 mg P release could result in 100 mg PHB production. The PHB production at the loading of 0.176 g/(g · d) was 4 mg/g MLSS less than that at 0.413 g/(g · d). No significant relevance was observed between PHB and BOD₅ removal. The PHB of microorganism synthesizes was increased with the increase of temperature. Compared with the lowest temperature (17.1°C), 20% of the total PHB content was increased at the maximum temperature (33.2°C) in active sludge.