aqualia has embraced sustainability in its ongoing desalination projects

By Javier Santiago

Lack of water has been an historical problem in Spain, especially in the South and East of the Iberian Peninsula and in both the Canary and Balearic islands. Due to this fact, Spanish companies have always been at the forefront of the desalination industry to solve these scarcity problems.

In fact, the very first desalination plants were built in the 80s in the Canary Islands. This region is a very dry one, where water is a key issue and desalinated water is one of the best solutions to guarantee drinking water for the public. Based on this experience, Spanish companies have exported their knowhow to other regions where desalination is needed, for example, North Africa, the Middle East and South America. These regions are currently suffering from a lack of water as Spain did many years ago and the expertise of companies like aqualia is highly valued.

aqualia has become a key player worldwide, building more than 30 desalination plants that provide over 700,000 m3/day of fresh water to over three million people. aqualia is currently developing desalination plants in Spain, Algeria and Chile, three markets with a lot of scope. In Chile, aqualia was recently awarded its first contract, which includes the development of a desalination plant and the supply, installation and commissioning of its electromechanical equipment. The plant will supply industrial water.

The Reverse Osmosis (RO) plant at the Mostaganem desalination plant

Currently, aqualia is building two desalination plants in the north of Algeria at Mostagamen and Cap Djinet. The capacities of both plants add up to over 300,000 m3/day of water. The Mostaganem desalination plant, which uses Reverse Osmosis (RO) technology is one of the biggest in the African continent with a production capacity of 200,000 m3/day. The water intake is an open one, and the pre-treatment is double filtration and microfiltration. There are up to eight lines (25,000 m3/day/each) with RO using spiral-wound membranes. The energy recovery system is by isobaric chambers and the remineralisation is with calcium carbonate and CO2.

The environmental policies we have applied in the Algeria desalination plants follow the recommendations of an in-depth study on environmental impact which we do for every design that we develop. I would like to highlight the recommendations pertaining to the execution and operation phases:

• A study of the zero state of the environment (both terrestrial and marine).

• The installation to produce minimal impact.

• A study of the system of dilution / dispersion of hypersaline effluent from the desalination plant, so that its effect on the medium is zero.

• Implementation of the outfall diffuser discharge so as to generate multi-jet and to ensure dispersion.

From the installation design point of view, we have applied the ‘least energy consumption’ principle. We have applied the practices and knowhow gathered from many years of experience installing the best equipment to decrease power consumption.

(The author is Managing Director, aqualia infraestructuras)