汕头湾沉积物磷的形态分布与季节变化特征研究

分别于2008年9月（平水期）、11月（枯水期）及2009年6月（丰水期）在汕头湾的13个站点采集表层沉积物样品,测定了其中的总磷、无机磷、有机磷,并采用SMT提取法提取并测定了各无机形态磷的含量,分析了其空间分布与季节变化特征.汕头湾表层沉积物中总磷、无机磷及其各形态磷在季节变化上表现为枯水期〉平水期〉丰水期;在空间上表现为由湾顶至湾外呈波状递减趋势,其高值区出现于汕头湾上游的牛田洋.无机磷是汕头湾沉积物磷的主要存在形态（94.06%）,无机磷中钙结合态磷所占比重最大（70.21%）,其次为可交换态磷和铁结合态磷,而以碎屑态磷最少（4.99%）.相关分析表明各种磷的来源相似,且在时空分布上受地表径流季节变化影响.其中有机磷、铁结合态磷和可交换态磷为生物可利用性磷,主要受控于其来源和水体氧化还原电位,而钙结合态磷和碎屑态磷生物利用性差,受区域内生物活动和地质特征影响显著.

Distribution Characteristics of Phosphorus Forms in Surface Sediments of the Shantou Bay in China

In order to know the horizontal distribution and seasonal variation characteristics of phosphorus species in surface sediment, the contents of different phosphorus species in the surface sediment sampling from Shantou Bay were determined by using the SMT sequential extraction method in September and November, 2008, and June, 2009.The contents of different phosphorus species basically showed an order of the low-water period, normal-water period and high-water period from high to low, and horizontal distributions of phosphorus species showed a decrease trend as waves from the inner bay to the outer bay with the maximum appeared in Niutianyang. The main form of total phosphorus in sediment was inorganic phosphorus, which accounted for 94.06%, and the content of Ca-P was the highest in all inorganic phosphorus of the surface sediment in Shantou Bay, comprising 70.21%, followed by Ads-P, Fe-P and De-P. The correlation analysis among different phosphorus forms suggested that they had similar sources and they were affected by surface runoff and seasonal variation. OP, Fe-P and Ads-P were bioavailable phosphorus, which were controlled by sources and water oxidation-reduction potential; while Ca-P and De-P were mainly influenced by biological processes and geological characteristics.