Page 199 - The Biochemistry of Inorganic Polyphosphates

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APPLIED ASPECTS OF

POLYPHOSPHATE

BIOCHEMISTRY

9.1 Bioremediation of the Environment

9.1.1 Enhanced Biological Phosphate Removal

The presence of considerable amounts of P i in wastewaters due to the run-off of fertilizers,
and industrial and household discharges, is a major problem, because destructive blue algae
blooms may develop in natural waters, where under normal conditions the P i concentration
is most often the limiting factor for algae growth (Godd and Bell, 1985).
It is also important to understand how PolyP 3 contained in common detergents is
hydrolysed in the environment and what ways may improve its removal. The major
factor contributing to PolyP 3 degradation in wastewater was shown to be biological by
nature, with the most likely mechanism being enzymatic hydrolysis (Halliwell et al.,
2001).
The currently available methods for removing P i from wastewater rely primarily on
PolyP accumulation in sludge bacteria, which accumulate considerably more phosphate
than is required for normal bacterial growth. This process is called ‘enhanced biological
phosphorusremoval’(EBPR)(Toerienetal.,1990).TheprocessofEBPRisnowanaccepted
and low-cost strategy for controlling eutrophication. The excess of taken-up P i is stored in
the form of PolyP granules, and thus PolyPs play the key role in EBPR. In addition, some
other extracellular polymers associated with cell clusters may act as a phosphorus reservoir
(Cloete and Oosthuizen, 2001).
The literature data on EBPR are now very numerous. There are many detailed reviews,
which summarize the data on technology, biochemistry, microbiology and molecular biol-
ogy of this process (Kortstee et al., 1994; Van Loosdrecht et al., 1997; Mino et al., 1998;
Bond and Rees, 1999; Kortstee and Van Veen, 1999; Ohtake et al., 1999; Kortstee et al.,

The Biochemistry of Inorganic Polyphosphates I. S. Kulaev, V. M. Vagabov and T. V. Kulakovskaya
C 2004 John Wiley & Sons, Ltd ISBN: 0-470-85810-9

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