As a supplier of holistic industrial water treatment solutions we offer made-to-order and turnkey industrial plants. One example of such is this project in Algeria from 2020:

Chriwa has realised a desalination plant in the city of El-Oued, Algeria, for the treatment of brackish water to drinking water from 2017 - 2020.

Chriwa‘s scope of services includes project planning, design, engineering, manufacturing, delivery, installation, electrical, automation and measurement technology as well as commissioning of the entire plant.

The plant technology consists of the components:

- Pumping station for filtered water

- Dosing

- Microfiltration

- High-pressure pumping station

- Reverse osmosis unit

- Membrane filter cleaning

- ESMR technology SPS S7

The capacity of the plant is 30,000 m³/d.

The water supply is provided by 3 deep wells. The water filtered by an on-site pre-filtration is sucked through a welded manifold and transported to the downstream fine filters (fineness 5 µm) by means of 4 feed pumps. The chlorine concentration and the conductivity of the water are measured between the pump station and the fine filters to monitor the process.

In the pressure line to the fine filters, the water is dechlorinated by dosing sodium bisulphite. Antiscaling is also dosed here to prevent precipitation within the reverse osmosis system. Both dosages are adjusted proportionally to the flow rate.

The water then passes through the 5 µm fine filters, which are dimensioned for the entire nominal flow rate. The delivery includes eight units with 39x40“ cartridges in each unit.

At the outlet of the fine filters, the water is brought to the osmotic pressure required for the process by means of high-pressure pumps. After the high-pressure pumps, a redox meter (ORP) is installed to monitor the residual chlorine. The pH value of the water and the temperature are also measured and monitored upstream of the reverse osmosis units.

The demineralisation process by reverse osmosis is dimensioned to guarantee the nominal flow rate in the used condition after three years of operation. The plant comprises four reverse osmosis units with a capacity of

4 x 315 m³/h of treated water and the recovery rate is 75 %.

To remove possible deposits on the membranes, the plant has an automatic membrane cleaning system. Cleaning takes place in individual stages.

After the Chriwa reverse osmosis desalination plant, the conductivity of the permeate is checked again and the treated water is then transferred to the storage and mixing tank for further use.