Raw Water Treatment - Technology

Plimmer® is based on the principles of Capacitive De-ionization (CDI). Capacitive Deionization is a technology for removing salinity from water. This innovative technology is used to desalinate water without using resin or membrane filters. It does not require chemicals to treat water and uses very low power to separate salts in water.

CDI Cells uses different coupled electrodes contained in a pressurized container, supplied with direct current at a potential difference of 1.6 Volt. The electrodes are placed at a distance at an order of magnitude of 0.1mm.


Powering the electrodes, an electrostatic field is created. The salts contained in the water, that possess an electric charge, will be attracted by the electrode with opposite charge and blocked its surface by the electric field.

Operating as low voltages, electrolysis and gas production will not occur. The result is the partial or total demineralization of the water.

The electrodes behave like those of a normal condenser. At a certain point, the ions will cover the whole surface of the electrodes, meaning that extra ions will not be captured. In these conditions, the Cells are at full capacity. Blocking the water flux and removing the power supply it is possible to measure on the electrodes a potential difference equal to the blocked ions on the surface. This energy will be dissipated by short-circuiting the electrodes. A maximum current is therefore obtained that will be used up in a short period of time.

The blocked ions are now in their original form and are contained in the small volume of the cell. A short rinse will turn them in concentrated form for waste or recycle.

Purification Process

When Water passes between the electrodes, the ions get attracted to opposite charged electrodes. The water void of these salts and metals come out of the system.

With more and more ions sticking to the electrodes, they become saturated - when this happens, the system automatically changes the polarity. The ions sticking to the electrodes fall off.

Water is then flushed between the electrodes and the wasted ions are flushed to drain. The polarity is reversed back and the Ion removal process(Step 1) starts again.

After the short-circuiting, the poles of the power supply are inverted for a short period of time in order to make the ion releasing and recombination process quicker. Plimmer® works according to condenser principle, holding back the ions on the electrode due to the potential difference applied on them. The p.d is in fact very low (approximately 1.5V) meaning that the system is intrinsically safe.

One big advantage that Plimmer® has is the fact that the percentage of demineralization can be varied according to the customers needs. This can be done by varying the potential difference across the electrodes from 1 to 1.6V. This characteristic, unique in respect to all machinery on the market, gives the chance to alter the water’s taste, adapting is for virtually infinite uses.