In addition to these applications, environmental applications of electrochemical engineering are not restricted to wastewater treatments. Thus, the treatment of gaseous flows is also a very interesting topic for electrochemical engineering and many attempts have been done during the recent years in order to develop novel applications. Thus, in addition to fuel cells applications for energy production from particular waste gaseous flows and to the very significant applications of the NEMCA effect (non-faradaic electrochemical modification of the catalytic activity) on the improvements of the catalytic oxidation or reduction of gaseous pollutants, there is a plethora of processes based on the absorption of a gaseous pollutants on aqueous solutions and in the later treatment of the liquid waste produced. However, the most applied processes nowadays are related to soil remediation. Electrokinetic soil remediation (EKSR) is one of the more interesting topics of research and application for electrochemical and environmental engineering nowadays. It consists of the application of a direct current electric field across contaminated soil through electrodes installed in the subsurface.
This current produces simultaneously various physical processes (such as heating, changes in viscosity), chemical processes (e.g. ion exchange, dissolution of precipitates), electrochemical processes (such as water oxidation and reduction), and electrokinetic processes (e.g. electroosmosis, electromigration, electrophoresis) which promote significant physicochemical changes in the soil. Suitable combination of these processes by applying optimum configurations and operation conditions to a soil remediation process can yield the removal of many inorganic and organic contaminants from soils. Hence, advances in applied electrochemistry mainly to solve environmental problems, such as wastewater treatment and soil remediation have recently led to great technological improvements, particularly in the design of reactors in which are held such processes. Several research groups around the world have worked on improving performance of these technologies, particularly energetic efficiencies, optimization of parameters such as pH, temperature, current density, electrode configuration, among others, all with the goal of increasing the amount of organic matter removed in an effluent or soil to be treated.
The aims of this book is to show the most important advances in the design of electrochemical reactors that have been used to solve various environmental problems, this right through five chapters covering different aspects such as, electrocoagulation reactors, boron doped diamond electrochemical reactors, Fenton-based water treatment process and electrokinetic remediation of polluted soil. In view of the above considerations, this book would be a very useful source of information to environmental researches, engineers and postgraduate student alike.