Abstract

The Chilika Lagoon is the largest brackish water ecosystem in the Asian continent and is a Ramsar site. Here, the sorption–desorption study was standardized simulating the environmental condition of the Chilika, to ascertain whether phosphorus (P) is the source or sink for sediments of the coastal ecosystem. The sorption behaviour of sediment phosphorus was better fitting into the modified Langmuir model. The effects of salinity, pH, and temperature on phosphorus sorption were found to be better understood by nonlinear relationships. The sorption was recorded to increase at its lower concentrations with increasing of mentioned parameters, when it decreased beyond some threshold values. The maximum phosphorus sorption capacity (Q_max) was more (258 mg/kg) in the freshwater stretch of the lagoon; Northern Sector compared to the relatively saline stretches, i.e., Outer Channel (219 mg/kg) and Southern Sector (237 mg/kg) (p < 0.05). This study will help to control eutrophication by increasing P sorption.

Highlights

1. 1.

   Phosphorus sorption and desorption study mark an unique for the Asian largest lagoon Chilika

2. 2.

   The behaviour of sediment phosphorus sorption was better expressed by the modified Langmuir model than by the alternative modified Freundlich model

3. 3.

   The maximum phosphorus sorption capacity (Qmax) was more in the fresh water stretch of the Chilika lagoon compared to the relatively saline stretches

4. 4.

   For management of eutrophication condition of the lagoon by increasing P sorption through restoration of the freshwater environment.

中文翻译：

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南亚最大的微咸水泻湖对磷的吸附行为

摘要

Chilika泻湖是亚洲大陆最大的微咸水生态系统，是拉姆萨尔（Ramsar）基地。在此，对吸附-解吸研究进行了标准化，以模拟Chilika的环境条件，以确定磷（P）是沿海生态系统沉积物的来源还是沉积物。沉积物磷的吸附行为更适合修正的Langmuir模型。通过非线性关系可以更好地理解盐度，pH和温度对磷吸附的影响。记录到当吸附量降低到某些阈值以上时，其吸附量会随着上述参数的增加而增加。最大磷吸附量（Q _max）在泻湖的淡水段中更多（258 mg / kg）; 与相对盐碱地带（即外河道（219 mg / kg）和南区（237 mg / kg））相比，北部地区（p  <0.05）。这项研究将有助于通过增加磷的吸收来控制富营养化。

强调

1. 1。

   磷吸附和解吸研究标志着亚洲最大的泻湖奇利卡的独特之处

2. 2。

   改进的Langmuir模型比替代的改进的Freundlich模型更好地表达了沉积物对磷的吸附行为

3. 3。

   与相对盐渍地段相比，Chilika泻湖的淡水段中的最大磷吸附量（Q max）更大。

4. 4。

   通过恢复淡水环境来增加磷的吸收，以管理泻湖的富营养化状况。