长江口滨岸潮滩沉积物中磷的环境地球化学特征

Environmental geochemical characteristics of phosphorus in intertidal sediments of the Yangtze estuarine and coastal zone

研究了长江口滨岸潮滩表层沉积物中磷的分布、形态等环境地球化学特征 .结果表明该地区表层沉积物中磷的含量水平在 18 0— 3 1 4μmol g之间 ,最大值出现在浦东白龙港污水排放口附近 .长江口滨岸潮滩沉积物中磷的分布呈现明显的空间和季节性变化规律 ,这主要与潮滩不同地段磷的来源、沉积物质地的差异 ,以及水动力、环境介质条件和生物作用的时空变化密切相关 .此外 ,沉积物中磷的形态分级研究表明大部分沉积磷以无机磷形式存在 ,其中无机磷又以钙结合磷为主 ;有机磷比例较少 .其次 ,潮滩沉积物表层上覆水中可溶磷的浓度一般都大于沉积物间隙水 ,沉积物

The distribution and forms of phosphorus (P) were investigated in intertidal surface sediments of the Yangtze estuarine and coastal zone. Total P concentrations in surface intertidal sediments ranged from 18.0μmol/g to 31.4μmol/g,and the maximal value occurred at the Bailonggang(BL) site which is near a sewage outlet. The P distribution presented spatial and seasonal variability, which was dominated by the resources of P input, sediment texture and a number of biogeochemical processes in different hydrodynamic and environmental conditions of the Yangtze estuarine. Moreover, significant variations in the forms of P in different sites were observed. Generally, organic P (Org-P) in sediments was lower, and P bound as Ca(Ca-P) was the dominant inorganic form in intertidal sediments. Accumulation may be the main process of P between water and sediment, according to the concentration gradient of dissolved P between surface water and pore water in sediments.