Dissolved organic carbon (DOC) undergoes an extensive number and variety of interactions in aquatic ecosystems. It exchanges protons, metals, and nutrients, it inhibits or stimulates microorganism growth, it attaches to colloid surfaces, etc. These interactions may appear at equilibrium within observation time scales or may appear reactive. They are studied to understand the basic character and function of DOC and to make predictions about its behavior under a wide range of environmental conditions such as concentration, temperature, pH, alkalinity, and ionic strength. (...)