『Abstract
The composition and the different forms of P, in an annual average
sample of particulate matter, have been determined to define the
nature of the very high concentration of particulate P in the
inflowing water of the Hollands Diep/Haringvliet (The Netherlands),
and to assess its potential to simulate the growth of aquatic
organisms.
Three phosphorus fractionation schemes and five other extraction
procedures have been applied. Seventy per cent of the total phosphorus
content is operationally defined as Fe- and Al-bound P but, probably,
only a discreet Fe-phosphate is present, with an atomic ratio
Fe/P = 1.5. About 50％ of total P is present as a colloidal form
(＜0.45 μm).
The results indicate that Murphy & Riley's procedure for
orthophosphate determination causes some hydrolysis of labile
organic phosphorus compounds.
A fractionation scheme, to determine the different forms of P
in particulate matter, is proposed.
The concentration of potentially algal-available particulate
P, which varies between 25 and 50 μg P l-1, has probably
no effect on water quality because the concentration of dissolved
orthophosphate (250 μg P l-1) is much higher. The huge
amounts of Fe-bound P stored in the sediments, however, may retard
the improvement of water quality in the future when reduction
of the phosphorus loading has been accomplished.
Keywords: particulate matter; P fractionation scheme; iron phosphates;
labile organic P; algal-available P』
Introduction
Materials and methods
Sampling
Chemical and mineralogical analyses
Selective extraction schemes for P
Extraction schemes
Scheme 1 (Hieltjes & Lijklema 1980)
Scheme 2 (Engler et al. 1977)
Scheme 3 (Williams et al. 1971) as modified by Li (1973)
Scheme 4 (Duinker et al. 1974; Sorensen et al. 1971)
Scheme 5 (Shukla 1973)
Scheme 6 (Spear 1970)
Scheme 7 (Cowen 1974)
Scheme 8 (Kemp & Mudrochova 1971)
Size fractionation
Results
Chemical and mineralogical composition
Phosphorus fractions
(1) Exchangeable-P, (2) carbonate-bound P and (3) hydrolysable-P
(4) Organic-P
(5) Fe- and Al-bound P
(6) Ca-bound P
Distribution of P as a function of grain sizes
Discussion
P-fractionation schemes
Labile organic phosphorus
Dissolution of clay minerals
Algal-available phosphorus
Fe- and Al-bound phosphorus
Acknowledgements
References
| 試料１ | 0.5M NaCl、30分間 | 残渣は廃棄 |
| 抽出液→Watanabe and Olsen DRP | 交換可能なP（Exchangeable-P） | |
| 試料２ | 1.0M NH4Cｌ（pH 7）、2時間2回 | |
|
抽出液 |
Murphy and Riley DRP（炭酸塩結合P−交換可能なP） | 不安定有機P（labile organic-P） |
|
抽出液 |
Watanabe and Olsen DRP（交換可能なP） | 炭酸塩結合P（carbonate-bound-P） |
|
残渣 |
0.1M NaOH、16時間 | |
|
抽出液 |
Murphy and Riley DRP | Fe・Al結合P（Fe- and Al-bound P） |
|
抽出液 |
Murphy and Riley TDP-DRP | 安定有機P（resistant organic-P） |
|
残渣 |
0.5M HCｌ、24時間 | 残渣は廃棄 |
| 抽出液→Murphy and Riley DRP | Ca結合P（Ca-bound-P） | |
|
DRP＝可溶の反応性リン酸塩（dissolved reactive phosphate） TDP＝全溶存リン（total dissolved phosphorus） |
||
※オルトリン酸塩と全リンは、Murphy & Riley（1962）を修正したEisenreich et al.（1975）／Watanabe & Olsen（1962）により分析。粒子状物質の分別法は、Hieltjes & Lijklema（1980）を使用。