DESCRIPTION

Technical Description

Ion exchangers are used in water treatment primarily for desalination and softening. CE 300 enables these processes to be demonstrated with the aid of cation and anion exchangers.

The raw water is pumped from the tank into the top of the cation exchanger. In the softening process the water flows from there back into the collecting tank. To desalinate the raw water, it is then additionally routed through the anion exchanger. From there the treated water passes into the collecting tank. In the regeneration process, acid or caustic is fed into the ion exchangers from below using the same pump. The acid and caustic used is collected in the collecting tank.

The flow rate of the pump is adjustable, and can be read from a flow meter before it enters the first ion exchanger. For continuous evaluation of the process, a conductivity sensor is installed upstream of the inlet into the collecting tank. The measured values can be read from a conductivity meter. Samples can be taken at all relevant points. Tap water can be used as raw water.

The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.

Learning Objectives / Experiments

- learning the fundamental principle of softening and desalination by ion exchange
- identification of the different modes of operation of cation and anion exchangers
- combined use of cation and anion exchangers for desalination
- exchanging capacities and regeneration
- verification of the theoretically calculated regeneration time