This book is a compendium of research efforts and findings on the sources, occurrences, hydrochemistry, and several operating variables that influence the presence of oxyanions in aqua system. The content of this book has been designed to provide an insightful account of an array of innovative technologies for the management of the impacts of oxyanions in water, the progress and drawbacks of these technologies and those that have been effectively deployed to transform oxyanions in water to beneficial species. This book further x-rays global laws and economic policies targeted at effectively curtailing the presence of harmful oxyanions in water, challenges facing these policies, and future perspectives on how best to reduce the level of these harmful oxyanions in water to safe limit. The book is relevant to water professionals, policy makers, academics, and research students.