Phosphatformen in Unterwasserböden Ca-reicher Fließgewässer

Forms of phosphates in underwater soils of Ca-rich running waters Underwater soils of small carbonaceous rivers in Upper Bavaria have phosphorus contents between 300 ppm in oligotrophic creeks and more than 0.2% in heavily polluted waters. The (Al,Fe)-P and the Ca-P occupied 20–35% and 28–38% of total phosphorus (P_t) resp., so that inorganic phosphates represent 53 to 64% of P_t. The correlation between P_t and carbonate is negative, but is positive between P_t and oxalate Fe or organic substance. Addition of P results in a relative increase of (Al,Fe)-P compared with other forms. Approximately 7 to 15% of total P is subject to isotopic exchange with ³²P.