Environmental Engineering Reference
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show an activity for degradation of both TPT and TBT and the ornibactins
show a weak activity for degradation of DPT.
They reported the adsorption and degradation of TPT by immobilized
Pseudomonas chlororaphis CNR15 cells. The cells were entrapped in calcium
alginate beads. Pyoverdin, which is a siderophore that participates in the
degradation of TPT, was secreted from the immobilized cells, and the concen-
tration of the pyoverdin increases for at least one month, and DPT and MPT
are formed [132]. The degradation activity was influenced by temperature
andpH,andshowedamaximumat30 C and pH 8.8 [132].
The pyoverdins also degrade DBT to MBT in seawater. The optimum
degradation of DBT in seawater was at pH 4.8-8.2, at a temperature of
25-30 C [129]. The TPT degradation by pyoverdin was markedly inhibited
by transition metal ions, Zn 2+ and Sn 4+ , while under the metal-free condi-
tion, its degradation seems to form a stable 1 : 1 complex with MPT without
Fig. 7 Degradation of [ 14 C] TBT added to Skidaway River water under dark and natu-
ral sunlight conditions [97]. The initial concentration of [ 14 C] TBT was 1.0
gL -1 .For
filteredsampleswaterwaspassedthrougha0.2- µ m filter. For the added nitrate study
there was an addition of sodium nitrate (10 mg L -1 ), which resulted in a chlorophyll
concentration of 21
µ
gL -1 . Initial chlorophyll concentration in the estuarine water was
6 µ gL -1 . Ve r t i c al b ar s represent one standard deviation with n = 3. TBT degradation was
significantly higher ( P = 0.05) in the light compared with dark degradation
µ
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