【摘要】 为了验证外源性Ca²⁺对沉积物中生物活性磷赋存形态制约的科学假说,在充气的条件下,将沉积物暴露于不同浓度外源性Ca²⁺中30天,测定并分析其生物活性磷的赋存形态的差异。浓度0、50、200、500 mg/L的外源性Ca²⁺暴露下的表层沉积物Ex-P含量为0.08±0.02、0.05±0.00、0.05±0.01、0.06±0.01μmol/g,50 mg/L的外源性Ca²⁺暴露下的表层沉积物Ex-P含量低于0 mg/L的外源性Ca²⁺暴露下的（P<0.05）;相同浓度外源性Ca²⁺暴露下的表层沉积物IP含量为0.37±0.10、0.46±0.16、0.41±0.06和0.69±0.05μmol/g,0 mg/L的外源性Ca²⁺暴露下的表层沉积物的IP含量低于500 mg/L的外源性Ca²⁺暴露下的（P<0.05）;底层沉积物Ex-P和IP含量不受外源性Ca²⁺的影响。故外源性Ca²⁺影响表层沉积物中生物活性磷含量,对沉积物Ex-P含量有双重阈值作用,并可将水体中的磷转化为可以缓释的沉积物磷。更多还原

【Abstract】 To verify the hypothesis that forms of bioactive phosphorus restricting the primary production in sediments can be influenced by exogenous calcium ions, sediments are exposed to calcium ions with different concentrations for 30 days and the differences of bioactive phosphorus forms in sediments was analyzed. The results showed that the Ex-P contents in surface sediments were 0.08±0.02, 0.05±0.00, 0.05±0.01 and 0.06±0.01 μmol/g respectively, when the concentrations of exogenous calcium ion were 0, 50, 200 and 500 mg/L respectively. The Ex-P content in surface sediment exposed to exogenous calcium ion with concentration50 mg/L is less than that in sediment exposed to exogenous calcium ion with concentration 0 mg/L(P< 0.05).Under the same concentration of exogenous calcium ions, the IP contents in surface sediments were 0.37±0.10,0.46±0.16, 0.41±0.06 and 0.69±0.05 μmol/g, respectively. The IP content in surface sediment exposed to exogenous calcium ion with concentration 0 mg/L was less than that in sediment exposed to exogenous calcium ion with concentration 500 mg/L(P< 0.05). Nevertheless, the Ex-P or IP content in bottom sediments was not influenced by exogenous calcium ions. Thus, the content of bioactive phosphorus can be influenced by exogenous calcium ions, and there are double threshold effects of exogenous calcium ions on Ex-P content in surface sediments. Moreover, the phosphorus in water body can be transformed into slow-release phosphorus in sediments by exogenous calcium ions.更多还原