Introduction to Wetland Systems

This introductory chapter provides a brief overview of the key wetland principles, which are not comprehensively covered in subsequent chapters. Most information provided is accepted knowledge that has been widely published elsewhere. The fundamental hydrological, physical, and biochemical processes within wetland systems are reviewed briefly. The relationships between aggregates and microbial and plant communities, as well as the reduction of predominantly biochemical oxygen demand, suspended solids, and heavy metals, are investigated. Most constructed wetland research studies show that after maturation of the biomass that dominates the litter zone, organic and inorganic contaminants are usually reduced similarly for all constructed wetland types. This finding is, however, still controversial, and further research needs to be undertaken. Particular emphasis in the introduction is given to treatment wetlands and wetlands used as sustainable drainage systems to control urban runoff. These technologies are further discussed with the help of recent and relevant research case studies in subsequent chapters.