When operating water and effluent treatment plants using flocculation, it is often argued that this "more an art than a science". It is certainly true that flocculation plants are extremely difficult to predict. However, a little knowledge goes a long way. This website is therefore dedicated to explaining the theory of flocculation and connecting the theory with the practice.

Processes

The Focus is on giving practical assistance to practitioners

Rather than explaining the flocculation process starting with the theory it was decided to start with the practice as followed in an actual plant and try and connect this with the theory. This website is dedicated to helping practitioners, not to be a scientific paper. We start, therefore, with flocculation, then flotation and settling, and finally filtration.

Fast Mixing

A controversy

Fast mixing is one of the processes that we will be examining in detail. We will discuss the limited effect from increasing the stirring speed, why diluting the flocculant is so important and the massive effect of addition points. But first you will have to wade through an extensive discussion on poly-cation formation and diffuse double layers.

Slow Stirring

Breaking up is o so easy to do!

Floccs are fragile. In fact they are so fragile that they break and re-form continuously. Slow stirring is therefore a balancing act between not letting your floccs settle in the stirring chamber and smashing them to bits.

Flocculation Pages to-date

I am trying to add at least one page a week:

1. Flocculation: The Basics
2. The Early Beginnings: Formation of Polycations and Nucleation
3. Joining them up: Polycation Chain/Network Formation
4. Neutralise and Wrap: Particle Removal