Particles matter: Transformation of suspended particles in constructed wetlands

This thesis shows that constructed wetlands transform suspended particles in (treated) municipal wastewater through selective precipitation in ponds, biological filtering by plankton communities and physical and biological retention in reed beds. These processes effectively remove faecal indicator bacteria and viruses, while in situ production generates suspended particles including bacterial consortia that closely resemble that of natural shallow water systems. This transformation is driven by a complex interaction of physical, chemical and biological processes occurring in the wetland ecosystem. Based on the observations in this thesis I have constructed an operational model describing these interacting processes in relation to changes in the concentrations, nature and type of suspended particles in wetland ecosystems. This model provides a scientific basis for the design of constructed wetlands optimized to protect our natural surface waters from harmful impacts of the increasing levels of suspended particles from different sources.