『Abstract
Concentrations of phosphorus (P) fractions and changes in their
bioavailability in the sediments as influenced by repeated resuspension
were determined by sequential fractionation in laboratory experiments.
The water and sediment samples used were taken from the campus
canal. Sequential fractionation indicated that the concentrations
of the iron bound P (BD-P) were predominant, consisting of over
50％ of total P (Tot-P) in the sediments that did and did not undergo
resuspension. BD-P mobility was reduced due to resuspension resulting
from the decline of the proportion ratio of non-occluded Fe-P
and occluded Fe-P from 0.53 to 0.29. Therefore, under sediment
resuspension conditions, using the sum of loosely sorbed P (NH4Cl-P), BD-P, aluminium bound P (Al-P), and organic-P
(NaOH-nrP) to estimate bio-available P (BAP) might be problematic.
However, BAP could be accurately estimated by the sum of NH4Cl-P, ％ BD-P (bioavailable, non-occlude Fe-P),
and NaOH-nrP. By this estimation, the amount of BAP in the sediments
as influenced by repeated resuspension decreased by about 10％
of Tot-P, compared with the initial state (raw sediments). The
results suggest that repeated resuspension could accelerate the
transformation of P from mobile fractions to refractory fractions,
which can be attributed to the increase of occluded Fe-P, Al-P,
and calcium bound P (HCl-P).
Keywords: Phosphorus extraction; Bioavailability; Resuspension;
Transformation』
1. Introduction
2. Materials and methods
2.1. Site description
2.2. Routine sampling
2.3. Sediment resuspension experiment design
2.4. Phosphorus fractionation
2.5. Analytical methods
2.6. Expression of results
3. Results
3.1. General characteristics of the sediments
3.2. DIP concentrations as influenced by repeated resuspension
3.3. Phosphorus fractions as influenced by repeated resuspension
3.4. Changes of bio-available P
4. Discussion
4.1. The variation of DIP migration
4.2. Sedimentary P fractions as influenced by repeated resuspension
4.3. Bio-available P as influenced by repeated resuspension
5. Conclusion
Acknowledgments
References
※リンの抽出法は、Rydin（2000）〔Psenner et al.（1988）〕による。