Abstract Sediment samples were collected from nine stations located along the Cochin estuary through five seasonal sampling campaigns for evaluating the distribution, accumulation and biogeochemical factors governing the concentration of various phosphorous fractions. Concentrations of sedimentary phosphorus fractions followed the order: iron-bound phosphorus > calcium bound inorganic phosphorous > alkali soluble organic phosphorus > acid soluble organic phosphorous > residual organic phosphorus. The enrichment of calcium bound inorganic phosphorous in the estuarine stations was found to exist in the high alkaline pH. Correlation study revealed that texture of the sediment controlled the distribution of iron bound phosphorous in the sediments. Terrestrial runoff carried huge quantities of humic substances to the riverine sediments that resulted in the peak concentration of alkali bound phosphorous at station S9 during monsoon. Increased levels of acid soluble organic phosphorous was recorded at stations with higher salinity (S5 to S8). Majority of the stations exhibited depleted levels of residual organic phosphorus due to the mineralization process. Meanwhile, total phosphorous ranged between 222.92 ± 3.89 µg/g and 4348.66 ± 15.35 µg/g with significant spatio-temporal variability (p < 0.01). Besides river run off resulted in the transport of organic matter derived from terrigenous, industrial, agricultural and aquaculture sources which brought about large scale accumulation of recalcitrant organic phosphorous in the sediments. Silt and clay exhibited remarkable positive correlations with iron-bound phosphorus, calcium bound inorganic phosphorous and alkali soluble organic phosphorus indicating the role of fine grained sediments in their dispersal mechanism. Multivariate statistical analysis revealed that distribution of phosphorous fractions were mainly controlled by salinity, granulometry, adsorption, desorption, precipitation, redox status, and the microbial processes occurring in the sedimentary environment.

中文翻译：

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印度西南海岸科钦河口选定表层沉积物中磷组分的归宿和运移过程

摘要 通过五个季节性采样活动从位于科钦河口沿线的 9 个站点收集沉积物样品，以评估控制各种磷组分浓度的分布、积累和生物地球化学因素。沉积磷组分的浓度顺序为：铁结合磷>钙结合无机磷>碱溶性有机磷>酸溶性有机磷>残留有机磷。发现河口站中钙结合无机磷的富集存在于高碱性pH值中。相关性研究表明，沉积物的质地控制着沉积物中铁结合磷的分布。陆地径流将大量腐殖质带到河流沉积物中，导致季风期间 S9 站的碱结合磷浓度达到峰值。在盐度较高的站点（S5 到 S8）记录到酸溶性有机磷水平的增加。由于矿化过程，大多数站点显示出残留有机磷的耗尽水平。同时，总磷介于 222.92 ± 3.89 µg/g 和 4348.66 ± 15.35 µg/g 之间，具有显着的时空变异性（p < 0.01）。除了河流径流导致来自陆源、工业、农业和水产养殖源的有机物质的运输，导致沉积物中顽固有机磷的大规模积累。淤泥和粘土与铁结合磷、钙结合无机磷和碱溶性有机磷表现出显着的正相关，表明细粒沉积物在其扩散机制中的作用。多变量统计分析表明，磷组分的分布主要受盐度、粒度、吸附、解吸、沉淀、氧化还原状态和沉积环境中发生的微生物过程控制。