ABSTRACT
Phosphorus is a critical nutrient for growth of algae and other aquatic organisms, accumulation of organic matter and the functionality of nutrient cycling and energy flow in an aquatic ecosystem. In a phosphorus-overloaded ecosystem, the sources of phosphorus may be classified as endogenous and exogenous. To control the overload of phosphorus, the two sources must be controlled at the same time; otherwise, the management strategies may not reach the target, especially in shallow lakes. The forms of phosphorus in waters can be categorized into three groups: orthophosphate, polyphosphates and organic phosphorus according to their chemical properties, or into two groups: particulate phosphorus and dissolved phosphorus according to their physical characteristics. In aquatic ecosystems, endogenous and exogenous phosphorus are in dynamic equilibrium. Exogenous phosphorus from effluent, nonpoint pollution, leaching from farmland and atmospherically deposition can be accumulated in sediment via biological or physical processes.
