A predictive, mechanistically based performance model for hydraulic flocculation could potentially enable improved design for hydraulic flocculators. Such a model would take characteristics of the flocculator and the suspension as inputs so that designers and operators could rationally consider effects of changing flocculator dimensions or influent water conditions on performance. A performance model exists for laminar flocculators, but a model applicable to turbulent flocculators is still needed, as real scale flocculators operate in the turbulent regime. This article outlines a theoretical approach that suggests the form of two dimensionless composite parameters that account for the influence of raw water turbidity, coagulant dose, flocculator hydraulic residence time, and energy dissipation rate on settled water turbidity. The utility of these parameters in describing turbulent flocculation will require testing and validation. Thus, this article also describes the design of a suitable laboratory test apparatus that produces turbulent flow conditions that mimic those in a baffled hydraulic flocculator. Preliminary experimental results are given.
All Science Journal Classification (ASJC) codes
- Environmental Chemistry
- Waste Management and Disposal
- drinking water treatment