"This thesis investigates the applicability of surface functionalization techniques for nanoscale zerovalent iron (NZVI) particles for improving the degradation of a toxic, common groundwater contaminant, trichloroethene (TCE). Although NZVI has emerged as a promising environmental remediation agent in the past decade and has the potential to transform a number of chlorinated organic pollutants to non-toxic end products, factors such as loss of electrons to reactions with water, formation of passivating oxide layers on NZVI surface and aggregation of NZVI to micron-sized particles pose significant challenges in the application of NZVI for TCE remediation. This research investigated techniques for the modification of NZVI surface with secondary metals (e.g. palladium), inorganic ions (e.g. sulfide), polyelectrolytes and surfactants (e.g. carboxymethylcellulose and rhamnolipid), and solid supports (e.g. activated carbon) to enhance reactivity through mitigation of the challenges mentioned above. The research was aimed at assessing the increases in reactivity, and also characterizing the fundamental physico-chemical processes that were responsible for the changes in reactivity. It was observed that organic macromolecules such as rhamnolipid (M.W. 600 g mol-1) sorbed on NZVI and prevented the deposition of rate enhancing surface dopants namely, palladium and sulfide, and inhibited TCE degradation. Conversely larger molecules such as carboxymethylcellulose (M.W. 700000 g mol-1) and humic acids bound to NZVI hindered deposition of the surface dopants to a lesser extent. Powdered activated carbon when used as a support for embedding NZVI was observed to significantly enhance the TCE degradation rate, however the method adopted for deposition of NZVI critically affected the rate enhancements because of changes in structural properties of activated carbon. Lastly, a phase transfer approach was developed to degrade the solvent (oil) phase of TCE using a rhamnolipid coated Pd-NZVI. This approach enabled 50% higher degradation of TCE solvent compared to a system where phase transfer was not employed." --

This is the first complete edited volume devoted to providing comprehensive and state-of-the art descriptions of science principles and pilot- and field-scaled engineering applications of nanoscale zerovalent iron particles (NZVI) for soil and groundwater remediation. Although several books on environmental nanotechnology contain chapters of NZVI for environmental remediation (Wiesner and Bottero (2007); Geiger and Carvalho-Knighton (2009); Diallo et al. (2009); Ram et al. (2011)), none of them include a comprehensive treatment of the fundamental and applied aspects of NZVI applications. Most devote a chapter or two discussing a contemporary aspect of NZVI. In addition, environmental nanotechnology has a broad audience including environmental engineers and scientists, geochemists, material scientists, physicists, chemists, biologists, ecologists and toxicologists. None of the current books contain enough background material for such multidisciplinary readers, making it difficult for a graduate student or even an experienced researcher or environmental remediation practitioner new to nanotechnology to catch up with the massive, undigested literature. This prohibits the reader from gaining a complete understanding of NZVI science and technology. In this volume, the sixteen chapters are based on more than two decades of laboratory research and development and field-scaled demonstrations of NZVI implementation. The authors of each chapter are leading researchers and/or practitioners in NZVI technology. This book aims to be an important resource for all levels of audiences, i.e. graduate students, experienced environmental and nanotechnology researchers, and practitioners evaluating environmental remediation, as it is designed to involve everything from basic to advanced concepts.

"Handling the high amount of waste generated by human activities is a current major challenge. Hazardous waste treatment activities focus on reducing damage caused to the environment and exposure to toxic substances by controlling the amount of untreated waste released into the environment. Although the goal of these activities is favorable in and of itself, they may have unintended consequences because treating the waste requires supplementary materials and energy and may produce toxic by-products. For instance, hazardous waste incineration processes showed to significantly damage the surrounding environment. However, thus far, it is one of the most common methods to treat chlorinated solvents waste, including trichloroethylene (TCE). In recent years, the use of nanoscale zerovalent iron particles (NZVI) for TCE degradation has received attention because of their ability to transform TCE into non-toxic products through chemical reduction reactions. However, degradation of TCE by NZVI in the aqueous phase is limited by NZVI selectivity to produce hydrogen with water and the growth of an oxide shell on the particles. To address this challenge, a NZVI-based treatment technology, in a novel biphasic reactor, has been developed for non-aqueous phase TCE treatment. The objective of the study is to assess the environmental performance of this technique in a life-cycle perspective, and to identify the configuration with the lowest environmental footprint. The impacts of the NZVI-based process, operating at ambient temperatures, are also compared to catalytic oxidation, an emerging technique for TCE treatment at higher temperatures. The Impact 2002+ model is chosen to evaluate the impacts on a wide range of environmental impact categories, on both global and local levels. The major observation from this study is that the total impacts of TCE degradation with NZVI can be reduced by controlling the amount of solvent used for the NZVI synthesis, choosing an appropriate doping method for the particles and recycling the reaction media. However, additional process optimizations must be achieved to significantly decrease the impacts of TCE waste treatment technique with NZVI. Further studies should also be conducted in order to ensure the validity of the results regarding nanoparticles production and end-of-life treatment impacts as, due to the novelty of the technology, current data rely on assumptions based on lab scale processes." --

Examines the suitability of nanoscale zero-valent iron (ZVI) for degradation of agrochemicals. This book identifies by-products produced from the ZVI-mediated degradation process of particular contaminants, and explains the reaction mechanism by which ZVI degrades a chosen contaminant.

Nanotechnology has a great potential for providing efficient, cost-effective, and environmentally acceptable solutions to face the increasing requirements on quality and quantity of fresh water for industrial, agricultural, or human use. Iron nanomaterials, either zerovalent iron (nZVI) or iron oxides (nFeOx), present key physicochemical properties that make them particularly attractive as contaminant removal agents for water and soil cleaning. The large surface area of these nanoparticles imparts high sorption capacity to them, along with the ability to be functionalized for the enhancement of their affinity and selectivity. However, one of the most important properties is the outstanding capacity to act as redox-active materials, transforming the pollutants to less noxious chemical species by either oxidation or reduction, such as reduction of Cr(VI) to Cr(III) and dehalogenation of hydrocarbons. This book focuses on the methods of preparation of iron nanomaterials that can carry out contaminant removal processes and the use of these nanoparticles for cleaning waters and soils. It carefully explains the different aspects of the synthesis and characterization of iron nanoparticles and methods to evaluate their ability to remove contaminants, along with practical deployment. It overviews the advantages and disadvantages of using iron-based nanomaterials and presents a vision for the future of this nanotechnology. While this is an easy-to-understand book for beginners, it provides the latest updates to experts of this field. It also opens a multidisciplinary scope for engineers, scientists, and undergraduate and postgraduate students. Although there are a number of books published on the subject of nanomaterials, not too many of them are especially devoted to iron materials, which are rather of low cost, are nontoxic, and can be prepared easily and envisaged to be used in a large variety of applications. The literature has scarce reviews on preparation of iron nanoparticles from natural sources and lacks emphasis on the different processes, such as adsorption, redox pathways, and ionic exchange, taking place in the removal of different pollutants. Reports and mechanisms on soil treatment are not commonly found in the literature. This book opens a multidisciplinary scope for engineers and scientists and also for undergraduate or postgraduate students.

Iron Catalysis: Design and Applications is an exciting new book that takes readers inside the world of iron catalysis guided by international catalysis expert, Dr Jose M Palomo. Iron is the most abundant metal in the planet, cost-effective, environmentally friendly, with an easily manipulated remediation process. In the last few years the use of this nonprecious metal has gained extraordinary attention particularly for its potential as a catalyst in different areas. This book compiles a series of chapters describing the most significant advances in the last few years since the design of different iron catalysts and nanocatalysts and iron-containing artificial and natural enzymes. The chapters also cover its application in different areas of interest such as organic synthesis, environmental remediation, enzyme-like activities or the creation of novel types of electrodes for battery design.

This book contains both practical and theoretical aspects of groundwater resources relating to geochemistry. Focusing on recent research in groundwater resources, this book helps readers to understand the hydrogeochemistry of groundwater resources. Dealing primarily with the sources of ions in groundwater, the book describes geogenic and anthropogenic input of ions into water. Different organic, inorganic and emerging contamination and salinity problems are described, along with pollution-related issues affecting groundwater. New trends in groundwater contamination remediation measures are included, which will be particularly useful to researchers working in the field of water conservation. The book also contains diverse groundwater modelling examples, enabling a better understanding of water-related issues and their management. Groundwater Geochemistry: Pollution and Remediation offers the reader: An understanding of the quantitative and qualitative challenges of groundwater resources An introduction to the environmental geochemistry of groundwater resources A survey of groundwater pollution-related issues Recent trends in groundwater conservation and remediation Mathematical and statistical modeling related to groundwater resources Students, lecturers and researchers working in the fields of hydrogeochemistry, water pollution and groundwater will find Groundwater Geochemistry an essential companion.