Estimation of intracellular phosphorus content of phosphorus-accumulating organisms at different P:COD feeding ratios.
The intracellular phosphorus content of phosphorus-accumulating organisms (PAO) was determined based on a stoichiometric equation and phosphorus balance for an enhanced biological phosphorus removal system fed with different P:COD ratios. The data indicated that a higher P:COD feeding ratio could significantly promote the growth of PAO. As the P:COD feeding ratio increased from 0.02:1 to 0.04:1 and 0.16:1, the phosphorus in the sludge increased considerably from 0.053 to 0.084 and 0.205 mg P (mg VSS(aerobic))(-1), respectively, indicating a dynamic condition in the microbial population. From the calculations, the mass fractions of the PAO, glycogen-accumulating organisms, and ordinary heterotrophs changed from 0.10-0.15, 0.83-0.88, and 0.02 at 0.02:1 to 0.19-0.28, 0.70-0.79, and 0.02 at 0.04:1 and to 0.478-0.71, 0.26-0.50, 0.03 at 0.16:1 P:COD feeding ratios, respectively. Despite the variation in microbial diversity, the calculated phosphorus contents of the PAO at all P:COD feeding ratios were consistent between 0.241 and 0.378 mg P (mg VSS(PAO))(-1). The initial specific phosphorus release and uptake rates were 84.7-167.9 mg P (g VSS(PAO))(-1)h(-1) and 52.8-90.0 mgP (g VSS(total))(-1)h(-1), respectively.
Panswad
Thongchai
T
Department of Environmental Engineering, Chulalongkorn University, Bangkok, Thailand.
Tongkhammak
Napaporn
N
Anotai
Jin
J
D000332:Aerobiosis; D007425:Intracellular Membranes / Q000378:metabolism*; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism*; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*
D012722:Sewage; D010758:Phosphorus; D010100:Oxygen