Description
Scitus Academics Transport And Fate Of Chemicals In Soils Principles And Applications by Prahlad Maurya
The weathering of the parent material by water determines, to a large extent, the chemical composition of the soil which has ultimately been produced. Some chemicals are leached into the lower soil layers where they accumulate. Other chemicals, more insoluble, are left in the upper layers of the soil. The most rapid removed chemicals are chlorides and sulphates, followed by calcium, sodium, magnesium and potassium. The silicates and oxides of iron and aluminium decompose very slowly and are rarely leached. When some of these products come into contact with the air in the soil, chemical reactions occur, such as oxidation in particular, which results in the formation of chemicals either more soluble or more fragile than the original ones. This results in an acceleration of the weathering processes, increased leaching* of chemicals, and further changes in the soil chemical composition. A freshwater acid sulphate soil may develop when the waterlogged soil containing iron sulphurs (pyrites) is exposed to the air, for example, when constructing ponds. Oxidation of the pyrites takes place and acidification of the soil occurs. The pond water may then become too acid for fish culture. The air present in the soil also contains carbon dioxide. This gas combined with water can form a weak acid (carbonic acid) which will then react with some of the soil chemicals to form new ones. This book, Transport & Fate of Chemicals in Soils: Principles Applications, offers a comprehensive treatment of the subject complete with supporting examples of mathematical models that describe contaminants reactivity and transport in soils and aquifers. This book details the basic framework of the physical and chemical processes governing the transport of contaminants, trace elements, and heavy metals in soils. Highly practical, it includes laboratory methods, examples, case study, and empirical formulations.