This volume includes five main topics: Reactivity and Transformations of Mineral Constituents and Metals at the soil-solution interfaces; Nature, Dynamics and Transformations of Organic Compounds and Enzymes in Soils; Microorganism-Colloid Interactions and their Effect on Bioavailability of Pollutants and Nutriments in Terrestrial and Freshwater Environments; Effect of Microorganism-Colloid-Soil Interactions on Dynamics and Activity of Microbial Communities and Populations; Integration of Mineral-Organic-Microorganism Interactions in the Evaluation of Soil and Freshwater Quality. These topics consider different aspects of the environmental behavior and fate of natural and anthropogenic organic and inorganic compounds in different soil systems and soil-surface water systems under the control of biotic and abiotic processes and parameters involved. In this book, overlap of processes, constituents, etc., between the different topics underline the occurrence, importance and interest of such interactions. In the near future such interactive phenomena will have to be much more defined to propose criteria of soil quality and of soil environmental functions that are needed to help management of the whole terrestrial ecosystem.