ABSTRACT

This chapter explores a review of concepts related to solute transport and mixing processes in water bodies. It presents key definitions in the area of hydrodynamics of reactors with focus on flow pattern classification and features in water and wastewater treatment units (WWTU). WWTU hydrodynamic efficiency assessment methods based on tracer techniques are the most commonly used, as applied in the field and laboratory scales through physical experimentation, or via computational simulations of hydrodynamic and solute mixing processes that mimic a tracer experiment. In WWTU literature, particularly from the unit processes perspective, the term ‘hydraulic’ is generally associated with flow-related aspects that somehow influence the treatment efficiency, with the HRT being the iconic ‘hydraulic’ parameter. The term ‘hydraulics’ is perhaps more easily recognised and generally understood by a non-hydrodynamicist audience, such as traditional process specialists and technical staff in the water industry.