长江口潮滩沉积物中磷的分布和形态特征

研究了长江口潮滩表层沉积物中磷的含量、分布及其形态特征．结果表明，沉积物中总磷（TP）的含量在539．6-3379．5mg／kg之间，石洞口（SDK）排污口处含量最高；磷的沿程空间变化明显，某些岸段夏季和冬季季节性变化较大，这主要受人类活动（排污）、沉积环境和水动力条件控制．除SDK样点有机磷含量偏高（43．6％）外，沉积物中有机磷（OP）含量较低；磷主要以无机磷（IP）形态存在，其中钙结合态磷（Ca—P）在IP中占主要地位，占54．4％～94．3％．沉积物中生物可利用磷（BAP）主要受人类活动控制，可以作为长江口潮滩环境潜在生态风险评价指标之一．

Distribution and Forms of Phosphorus in Intertidal Sediments of the Yangtze Estuary

The distribution and forms of phosphorus(P) were investigated in intertidal surface sediments of the Yangtze estuarine.Total P(TP) concentrations in tidal surface sediments ranges from 539.6 to 3 379.5 mg/kg.The maximal content of TP occurs at the SDK site which is located at the sewage outlet of Shidongkou.The P distribution presents spatial and seasonal variability,which is dominated by the resources of P input,sediment texture and a number of biogeochemical processes in different hydrodynamic and environmental conditions of the Yangtze estuary.Moreover,significant variations in chemical forms of P in different sites are observed.Except for SDK(43.6%),organic P(OP) in sediments is lower;inorganic P(IP) is the main form,and Ca-P is the dominant form of IP in intertidal sediments which account for(54.4%)-94.3%.The bioavailable phosphorus(BAP) is mainly controlled by human activities,which can be used as one of indicators for the potentially ecology risk assessment in the Yangtze estuary.