PPTAC/1 Computer Controlled Water Treatment Plant (filtration, adsorption, and ion exchange)

The Computer Controlled Water Treatment Plant 1, "PPTAC/1", designed by EDIBON, allows to study the main principle of the critical operations in the water treatment.

These operations are: depth filtration, adsorption and ion exchange.

The general objective of the exercises is to achieve the best possible treated water quality. The unit can be used to perform three variations of the specified processes:

• Filtration.
• Filtration and adsorption.
• Filtration, adsorption and ion exchange.

The unit is mounted on a floor standing metallic structure and consists of two modules connected by a set of hoses.

One module is composed of a supply unit and a water treatment unit. The raw water section includes a tank, a computer controlled pump to impel the water from the tank to the gravel filter and a line to introduce air optionally. This aeration ensures the raw water is mixed through and allows to precipitate the dissolved substances. The treated water section includes a tank to collect the water outlet of each operation in the water treatment plant (depth filtration, adsorption and ion exchange). Both tanks have level switches.

The other module includes the water treatment unit, which is connected to the tanks of the supply unit and consists of two filters, two adsorbers and two ion exchangers.

Raw water is pumped from the raw water section of the supply unit into a gravel filter and then routed into a sand filter. In the filtration process, the undissolved particles (suspended solids) are removed by passing the water through the filtering media (gravel and sand).

Filtered water can flow into the second treatment stage or can flow into the treated water tank, depending on the position of the circuit electrovalves. In the second stage, the dissolved particles (organic and inorganic contaminants) of the filtered water are removed by adsorption on aluminum oxide (first filter) and on activated carbon (second filter).

Water can flow into the third treatment stage or can flow into the treated water tank, depending on the position of the circuit electrovalves. In the third stage unwanted ions are removed from the water by ion exchange. First, water is softened by cation exchange, and then it is desalinated in a mixed bed ion exchanger, formed by cations and anions. At last, the treated water flows into the treated water tank.

All the relevant parameters (flow rate, pressure, differential pressure, temperature, conductivity) are recorded by sensors. Samples can be taken at all relevant points of the unit.

This Computer Controlled Unit is supplied with the EDIBON Computer Control System (SCADA), and includes: The unit itself + a Control Interface Box + a Data Acquisition Board + Computer Control, Data Acquisition and Data Management Software Packages, for controlling the process and all parameters involved in the process.