胶州湾沉积物中的磷及其环境指示意义

研究了胶州湾沉积物中磷形态的地球化学分布特征、控制因素及环境意义,将胶州湾沉积物中的磷分为可交换态磷、铝结合态磷、铁结合态磷、闭蓄态磷、自生钙磷、碎屑态磷和有机磷7种不同的形态,并结合210Pb测年法计算了不同年代各形态磷的埋藏通量,在此基础上,分析了胶州湾沉积物中磷所给出的环境信息.结果表明,无机磷是胶州湾沉积物中磷的主要形态,有机磷只占较小的比例,无机磷中钙磷占的比例相对较大,其中碎屑态磷是含量最高.磷的含量及埋藏通量的垂向分布受到pH、盐度、温度、生物扰动、沉积速率等环境因子的影响.相关分析及元素的OC/OP比值分析证明,近20a,陆源输入是胶州湾沉积物主要来源,并且沉积速率不断增大.由于近年来采取的较为得力的治污与排放措施,胶州湾的环境状况已有明显改观.研究还表明,Fe-P,Al-P和Oc-P的含量与海域污染程度有较密切的关系,可作为表征海洋沉积环境污染状况的指示因子之一.

Phosphorus and Its Environmental Marker Function

Phosphorus is a key biogenic element and plays an essential role in global biogeochemical cycles.The geochemical characteristics of phosphorus as well as the controlling factors and the environmental marker function in Jiaozhou Bay sediments were presented.The different forms of sedimentary phosphorus were studied in three sediment cores,which are forms of inorganic phosphorus,exchangeable phosphorus,phosphorus bound to Al-Fe,and calcium,occluded phosphorus as well as total phosphorus and organic phosphorus,respectively.The vertical profiles of various forms of phosphorus in response to(()~(210)Pb) chronological studies of sediment cores were investigated in order to reveal sedimentary environment changes.The results showed that inorganic phosphorus was the dominant form of total phosphorus and organic phosphorus was only the minor part.The detrital carbonate-bound phosphorus was the largest part of total phosphorus.The concentrations and burial fluxes of phosphorus were controlled by source and environmental factors including pH,salinity,temperature and grain size of sediments etc.Moreover,the analysis of OC/OP ratios suggested that the terrestrial inputs were the dominant source of Jiaozhou Bay sediments.The sedimentation fluxes of phosphorus increased in the past two decades,as a result,the pollution was still serious from the 1980 to 2000.But the state has greatly improved since 2000.The Fe-P,Al-P and Oc-P have close relationships with the degree of pollution and may act as good indicators for environment pollution in Jiaozhou Bay.