Te. Cloete et M. Bosch, ACINETOBACTER CELL BIOMASS, GROWTH STAGE AND PHOSPHORUS UPTAKE FROM ACTIVATED-SLUDGE MIXED LIQUOR, Water science and technology, 30(11), 1994, pp. 219-230
Citations number
17
Categorie Soggetti
Water Resources","Environmental Sciences","Engineering, Civil
Enhanced biological phosphorus removal activated sludge plants often d
o not remove phosphorus adequately in order to meet legal demands. Cur
rently FeSO4 is being added to almost all South African nutrient remov
al activated sludge systems discharging effluents to the sensitive cat
chments to prevent phosphorus from entering fresh water systems. In or
der to understand biological phosphorus removal mechanisms in order to
optimise the process, the role of growth rate and phosphorus removal
in Acinectobacter was investigated. Phosphorus was accumulated in the
lag phase of the normal growth cycle. Little or no phosphorus was accu
mulated in the logarithmic growth phase, instead phosphorus was releas
ed at the beginning of logarithmic growth. Further phosphorus accumula
tion took place in the stationary phase, once active growth had ceased
. Cells bad a limit to the amount of phosphorus that could be accumula
ted per cell irrespective of substrate availability. It was therefore
concluded, that the number of cells (biomass) in a system and their gr
owth stage were crucial factors governing biological phosphorus remove
d. Maximum cell numbers should therefore be obtained and logarithmic g
rowth should be prevented in the aerobic zone, in order to optimize bi
ological phosphorus removal from activated sludge.