The goal of this book is to improve understanding of the role wetlands perform in processing nutrients and contaminants, and to discuss and demonstrate how restored and constructed wetlands in the future, via their associated ecosystem services, can contribute to ensure sustainable water management and resource recovery while at the same time regulating and mitigating impacts of global climate change. Topics covered include:•various treatment wetland types, e.g. free water surface wetlands, subsurface flow wetlands, and intensified wetlands•the performance of treatment wetlands for different types of water, e.g. greywater, industrial wastewater, and agricultural runoff•the performance of treatment wetlands for removing selected micro-pollutants•the impact of salinity on the treatment performance.In Focus – a book series that showcases the latest accomplishments in water research. Each book focuses on a specialist area with papers from top experts in the field. It aims to be a vehicle for in-depth understanding and inspire further conversations in the sector.