沉积物磷生态环境风险评价方法的研究

Phosphorus (P), as one essential mineral nutrient element for life activity, is regarded as a limiting factor for water body eutrophication. When P in sediments exceeds a certain threshold, its release may induce risk of water bodies to eutrophication. Guided by precipitate/dissolution theory, the project propose will firstly focus on the interaction of P with acid under optimized conditions with aims to construct procedures to extract P by strong acid and determine the acid-consumption of sediments based on an results of form and component of P in different sediments; Secondly, the method for stability assessment of P-bearing minerals will be constructed using the relationship between P storage index (PSI) and available P in sediments, in which the former is calculated with acid-dissolved P and acid-consumption; Then, consulting the model using to judge potential of soil P supply, the method for ecological environment risk assessment will be built up and the border how to us them will be given. The results obtained in the current propose will be very helpful to understand the relationship between substance components and phosphorus loading of different property sediments, which is tightly linked to mechanism for release of internal P. Of course, the methodology explored in this project is also very valuable to some fields such as ecology, soil sciences and oceanology.

磷是生命活动必需的矿质营养元素，也是水体富营养化主要限制因子。沉积物磷超出基准阈值时，存在诱导水体富营养化的风险。本项目拟以沉淀/溶解理论为指导，通过不同性质沉积物的磷形态组成和与酸反应特征的研究，优化反应条件，建立沉积物磷的提取方法和沉积酸消耗量的测定方法；根据提取磷和酸消耗量，计算沉积物的磷赋存指数（Phosphate Storage Index, PSI），并利用磷赋存指数与有效磷的关系，构建沉积物磷稳定性的评价方法；同时，借鉴土壤磷素供应潜力的划分思路，建立沉积物磷生态环境风险评价方法，并阐明应用边界。该项目有助于深入了解不同性质沉积物的磷负荷与物质组成的关系，揭示内源磷释放的实质；拟采用的研究方法还可为其它学科如生态学、土壤学、海洋学等所借鉴，并提供有价值的资料。

磷是富营养化的主要限制因素，沉积物是水体的磷源，研究沉积物磷的释放风险对指导水生态系统管理具有重要科学意义，项目通过沉积物磷形态组成与沉积物性质的关系，沉积物磷的酸反应特征，沉积物磷生态环境风险评价方法的构建和沉积物磷生态环境风险评价方法验证及校正等研究，得到了利用酸溶解沉积物磷，获取磷赋存指数的方法，并结合水质关系，提出了磷赋存指数0.5为标准值，将沉积物磷风险分为5级，用于沉积物磷生态环境风险评估，这些成果对评价具体水体的营养现状，指导水资管理等方面具有重要意义。在项目实施过程中，取得发表SCI论文4篇，授权专利3件，培养研究生5名等成果。