桑沟湾沉积物中磷的赋存形态及生物有效性

Forms and Bioavailability of Phosphorus in Surface Sediments from Sungo Bay

以桑沟湾表层沉积物为研究对象，利用连续提取法对8个采样点沉积物中磷的赋存形态、含量及分布特征进行了研究，并探讨了磷的生物有效性．结果表明：①无机磷（IP）是桑沟湾表层沉积物中磷（TP）的主要形态，平均占总磷的73．33％，有机磷（OP）只占较小的比例．②无机磷中钙结合磷占的比例相对较大，平均占总磷的45．22％，是沉积物中磷的主要赋存形态，可交换磷、铁结合磷、碎屑磷占总磷的比例分别为9．92％、4．74％、13．46％．③对各形态磷的相关分析结果表明，总磷的含量及空间分布主要受有机磷的影响与控制（P〈0．05），无机磷受自生钙结合磷的影响较大（P〈0．01）．④磷的生物有效性分析结果表明，桑沟湾表层沉积物中潜在生物有效性磷的含量为358．05-448．39μg/g，平均占总磷的86．54％，具有很强的释磷潜力．

Forms and bioavailability of phosphorus in the sediments of eight sampling sites from Sungo Bay were analyzed by means of sequential extraction method （SEDEX）. Results showed that： ①The main form of total phosphorus （TP） in sediments was inorganic phosphorus （IP）, which accounted for 73.33 % and organic phosphorus （OP） was only the minor part. ② Among different forms of inorganic phosphorus, calcium-phosphorus （Ca-P） was the dominant forms, accounted for 45.22% of total phosphorus while organic phosphorus, adsorbed- phosphorus （Ads-P）, iron-phosphorus （Fe-P） and detritus-phosphorus （Detr-P） was 26.67%, 9.92%, 4.74% and 13.46% respectively. ③The correlation analysis among different phosphorus forms suggested that the concentrations and distribution of total phosphorus were mainly controlled by organic phosphorus （p〈0.05）, while inorganic phosphorus was affected by calcium-phosphorus （p〈0.01）. ④Bioavailable phosphorus in sediments ranged from 358.05 μg/g to 448.39 μg/g and occupied 86.54% of the total phosphorus pool.