『Abstract
The lateral distribution patterns of different forms of phosphorus
(P) in some Baltic Sea sediments were investigated by a sequential
extraction procedure. The distribution and amount are mainly related
to redox state, grain size, organic content and the chemical characteristics
of the sediments. Recalculation from mol P per day weight (d.
w.) to mol P per unit area indicates that coarse sediments typical
of transportation bottoms contain more total P than the finer
sediments found in accumulation areas, This is applicable for
almost all extracted P fractions.
The extraction procedure shows that HCl-extractable P, often
referred to as apatite-P, is the dominating fraction of almost
all sediment types. Oxidized fine-grained sediments of the near-shore
area and the archipelago are enriched in the hydrogen sulfide
(H2S) extractable P fraction. However, also
some transportation bottoms dominated by slightly coarser grain
size, i.e. silt instead of clay, have incorporated large amounts
of P.
A rough estimate indicates that the overall importance of a redox-dependent
release of P from the sediments is of secondary importance compared
to the total amount load.
A predictive calculation of the importance of a hypothetical
oxidation of all accumulation bottoms in the Baltic proper indicates
that the optimally adsorbed amount of P to these bottoms may represent
about twice the annual load. However, this calculation represents
an extreme potential uptake. A more realistic adsorption uptake
is probably far less than two years' supply.
The sorbing capacities of the archipelago and near-shore sediments
are today of great importance for the net balance of P in comparison
to that of the off-shore sediments. Furthermore, the study also
implies that other incorporation mechanisms must occur to balance
the total annual load entering the Baltic proper.』
1. Introduction
2. Materials and methods
2.1. Extraction procedure
2.1.1. Brief background
2.1.2. Extraction scheme
3. Results and discussion
3.1. Potential redox-dependent large-scale release/binding
of phosphorus
3.2. The importance and amount of phosphorus association to other
particular sediment parameters
4. Concluding remarks
Acknowledgements
References
|
抽出剤 | 方法など | 文献 | |
1 |
交換可能なリン (exchangeable P) |
pH 8.2に調節された1M NaOAc | この溶脱ステップはゆるく吸着したリンと孔隙水のリンを抽出することが仮定されている | Tessier et al. 1979 |
2 |
カルシウムに伴うリン (Ca-associated P) |
pH 5.0に調節された1M NaOAc | Ca炭酸塩に伴うリンを示すと推測された;Balzer(1986)は、Williams et al.(1980)からのデータによって還元できる随伴リン画分の前にCaに伴うリンを抽出する必要性を強調した | Tessier et al. 1979 |
3 |
還元できるリン画分 (reducible P fraction) |
硫化水素(H2S) | この画分は堆積物中の還元できる化学種に伴ったすべてのリンからなり、つまりもっぱら鉄に伴うものである | Krom & Berner 1980 |
4 |
残った無機リン (remaining inorganic P) |
1M HCl | この溶脱ステップはHieltnes & Lijklema(1980)の抽出法と一致する | Hieltnes & Lijklema(1980) |
5 |
全無機リン (total inorganic P) |
抽出(1)〜(4)の加算 | 異なる堆積物試料も1M HClで直接処理されたものとすべての「無機リン画分」の合計との妥当性をチェックすること;この2つのアプローチ間の最大不一致は<±8%であること(表2) | |
6 | 全リン(total P) | 5M HNO3 | 酸化する酸を用いてオートクレーブにより決定する | 例えば、Love(1967) |
7 | 有機リン(organic P) | 差により決定 | 全リン量から全無機リン量を差し引く |