The physical and chemical factors controlling sediment release and water column cycling of phosphorus and other nutrients (internal loading) are discussed within a 'systems' framework. Applying the systems approach, time-dependent nutrient storage within identified compartments, and fluxes between compartments are identified and interpreted mechanistically. The lake 'system' is partitioned into four main compartments, the lake water, atmosphere, tributary land drainage, and underlying sediments. The lake water and adjacent sediments are further partitioned along the vertical axis to reflect seasonal thermal stratification, and sedimentation processes. The important mechanistic paradigms applied to the 'system' include transport phenomena in density stratified fluids subjected to wind power, and the interacting geochemistries of iron, phosphorus and sulfur in bicarbonate-buffered natural waters. The purpose of the model is to identify the chemical and morphological factors regulating phosphorus recycling in lakes, and lay a mechanistic foundation for a general model of the phosphorus 'economy' of the epilimnion.

"Prepared for Office of Water Regulations and Standards, Criteria and Standards Division ; prepared by Environmental Research Laboratory."--GPO catalog card. "Research and development"--Cover. "Water Chemistry Laboratory, University of Wisconsin." "April 1981." "EPA-600/3-81-015." Includes bibliographical references (pages 79-89).