Effects of Suspended Particulates and Chemical Interactions

Particulates in estuarine systems are composed of both seston (discrete biological particles) and inorganic lithogenic components. An operational cutoff definition of 0.45 pm is used in this section to discriminate particulates—more details on the role of colloidal particles are discussed in chapters 8, 14, and 15. The highly dynamic character of estuarine systems (e.g., tides, wind, resuspension) can result in considerable variability in particle concentration over diurnal time intervals (Fain et al., 2001). Moreover, the reactivity of these particles can change over short spatial intervals due to rapid changes in salinity, pH, and redox conditions (Herman and Heip, 1999 Turner and Millward, 2002). 

The laws of thermodynamics are the foundation for chemical systems at equilibrium. 

Under standard conditions G, H, and S are represented as AG° and AH0, and AS0 and are referred to as the standard free energy of formation, enthalpy of 

It is well established that temperature increases chemical reaction rates and biological processes. Particularly important in estuarine biogeochemical cycles are the effects on microbial reactions commonly described by the well-known Arrhenius equation k = Ae Ea/RT. 

Some of the unique properties of water that stem from it s dipolar character are as follows (1) an excellent solvent (2) thermal expansion (3) high surface tension and viscosity (4) high dielectric constant (5) high specific heat and (6) high latent heats of fusion and evaporation. 

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