The solid-solution interface. Adsorption mechanisms in aquatic surface chemistry. Adsorption mechanisms. Organic compounds. Inorganic compounds. The electric double layer at the solid-solution interface. Electronic work function and potential of zero charge. Single-crystal electrodes. The problem of polycrystalline electrodes. Specific ionic adsorption. Adsorption of neutral molecules. Chemisorption and surface mobility. A two-phase model for the interpretation of proton and metal ion interaction with charged polyelectrolyte gels and their linear analogs. Development of the unified model. Application of the unified model to the interpretation of proton and metal-ion interaction with various charged polymeric systems. The surface chemistry of oxides, hydroxides, and oxide minerals. Coordination chemistry of the oxide-water interface. Acid-base characteristics of surface hydroxyl groups. Metal complexes. Adsorption of anions. Ternary surface complexes. Aspects of the molecular structure in surface complexes; spectroscopic investigations. Cation adsorption. Anion and organic ligand adsorption. Final considerations. Surface chemical processes in soil. Soil materials. Available models. Applicability of the models to the soil water system. The formation and dissolution of solid phases. The hydrolysis of iron in synthetic, biological, and aquatic media. Mononuclear aquahydroxo complexes of iron (III) and the primary steps of polynuclear growth. Hydrolysis in salt solutions. Iron hydrolysis in cells. Aquatic media: hydrolysis induced by oxidation of ferrous ions. The morphological variety of hydrolysis products. The dissolution of oxides and aluminum silicates; examples of surface-coordination-controlled kinetics. Surface-controlled dissolution. The ligand-promoted dissolution of ... The proton-promoted dissolution of hydrous oxides. Kinetic dependence on solute concentrations; fractional reaction orders. Weathering. The role of chemical weathering in the neutralization of acids. Reductive dissolution of metal oxides. Oxidation state and solubility. The geochemical setting. Dissolution without changes in oxidation state. Mechanism of reductive dissolution. Kinetics of reductive dissolution: simple models. Kinetics of reductive dissolution: additional considerations. Adsorption of redox-inert species. Effects of oxide mineralogy and surface structure. Experimental verification of theory. Monte Carlo simulations of surface reaction rate laws. Surface reaction rate laws: simple models. Dislocations. Monte Carlo model. Results and discussion. Dislocations with a strain field included. New evidence for the mechanisms of dissolution of silicate minerals. Evidence of surface reaction control during dissolution of silicate minerals. New data on the dissolution of silicates and the surface reaction hypothesis. Concluding remarks. Regulating the composition of natural waters. Surface chemical aspects of the distribution and fate of metal ions in lakes. Interactions of metal ions with surfaces of natural particles. Interaction of metal ions with biota: simple chemical models. The role of settling particles in the vertical transport of metal ions in lakes. Interpretation of metal complexation by heterogeneous complexants. Background: metals and ligands. Measurement of metal-ligand complexation equilibrium data. Representation of complexation equilibria. Application of the G(K') function to interpretation of heterogeneous complexant properties (Using Metal-Fulvic Interaction). Particle-particle interactions. Particle transport. Chemical aspects. A physicochemical synthesis. Environmental applications. The role of colloids in the partitioning of solutes in natural waters. Surface reactions of ions and polar compounds. Organic film solvation of hydrophobic compounds. Strange observations. Experimental artifacts. Reversibility of colloid aggregation. Artifacts and reality. Coagulation kinetics and simulations of particle-size distributions. Size distributions in peptizable suspensions. Apparent partition coefficients in natural waters. Abiotic transformation of organic chemicals at the particle-water interface. Kinetic models and equations. Heterogeneous organic reactions in sediment suspensions. Heterogeneous photoreactions. The role particles in regulating the composition of seawater. Particle in the ocean. Classification of deep-ocean profiles. Deep-ocean profiles of the elements. From molecules to planetary environments: understanding global change. Change. Observation. Earth convection: megaprocesses: geochemical cycles. Erosion. Bioprecipitation.