Eutrophication level in lakes and reservoirs depends on both internal and external phosphorus (P) load. Characterization of sediment P fractionation and identifying the P pollution sources are important for assessing the bio-availability of P and the dominant P source, for effectively controlling the water pollution. For determining the availability and sources of sediment P and eutrophication status, spatio-temporal variation in different P fractionation of sediment of hyper-eutrophic Krishnagiri reservoir, Tamil Nadu, India, was investigated. Sediment average total P (TP) content ranged from 4.62 to 5.64 g/kg. Main phosphorus form was the inorganic P (IP), and it makes up to 73.4–87.7% of TP. Among the different P fraction, viz. calcium bound (Ca-P), iron bound (Fe–P), aluminium bound (Al-P), exchangeable (Ex-P) and Organic-P (Org-P), Ca-P was the dominating fraction in both IP and TP. Trend of IP fraction was as follows: Ca-P > Fe–P > Al-P > Ex-P in pre-monsoon season, Fe–P > Ca-P > Al-P > Ex-P in monsoon and Ca-P > Al-P > Fe–P > Ex-P in post-monsoon. Overall the trend was as follows Ca-P > Fe–P > Al-P > Org-P > Ex-P. Bio-available-P (BAP) fractions ranged from 35.2 to 64.0% of TP, indicating its comparative higher value. Pearson’s correlation matrix revealed that there was strong correlation among the different P fractions. Factor analysis indicates that different fractions of P were the dominating factor than the other sediment parameters. The observed variation in sediment P fractionation indicate the differences in source and characterization of P which is very helpful for implementation of effective management practices in controlling pollution that arises due to phosphorus in this hyper-eutrophic reservoir.

湖泊和水库的富营养化水平取决于内部和外部的磷 (P) 负荷。沉积物P分馏表征和P污染源识别对于评估P的生物有效性和主要P源，有效控制水体污染具有重要意义。为了确定沉积物 P 的可用性和来源以及富营养化状态，研究了印度泰米尔纳德邦超富营养化 Krishnagiri 水库沉积物不同 P 分馏的时空变化。沉积物平均总磷（TP）含量为4.62～5.64 g/kg。磷的主要形式是无机磷（IP），占总磷的73.4-87.7%。在不同的 P 分数中，即。钙结合 (Ca-P)、铁结合 (Fe-P)、铝结合 (Al-P)、可交换 (Ex-P) 和有机-P (Org-P)，Ca-P 是 IP 和 TP 中的主要部分。IP分数的趋势如下：季风前Ca-P > Fe-P > Al-P > Ex-P，季风和Ca-P中Fe-P > Ca-P > Al-P > Ex-P > Al-P > Fe-P > Ex-P 在季风后。总体趋势如下：Ca-P > Fe-P > Al-P > Org-P > Ex-P。生物有效磷 (BAP) 分数范围为 TP 的 35.2% 至 64.0%，表明其相对较高的值。Pearson 相关矩阵显示，不同 P 分数之间存在强相关性。因子分析表明，与其他沉积物参数相比，不同比例的 P 是主要因素。