Station d’épuration des eaux usées de Jebel Ali

Une capacité de traitement journalière de 370,000 m³ pour la verte Dubaï

Réalisation phare et emblématique, la station d’épuration des eaux usées de Jebel Ali, située dans une zone désertique de 670 ha au sud de Jebel Ali, est le plus grand projet de ce type jamais réalisé par BESIX. Elle assure le traitement de l’ensemble des eaux usées de Dubaï conformément aux normes internationales et sans impact sur l’environnement.

Unprecedented magnitude

Combined with the existing Jebel Ali Phase 1 sewage treatment works, the new facilities treat the equivalent of the sewage flow originating from a city of 3.35 million inhabitants. A project of this magnitude is unprecedented in the GCC region. All sewage water is treated up to Dubai’s strict irrigation water standards and allows the city to cut back the use of costly desalinated seawater for non-potable use by 700,000,000 litres per day through re-use applications such as irrigation. The second phase of the project was completed using 143,000m³of reinforced concrete, 24,000 tons of reinforced steel, 2659 mechanical and engineering equipment and machinery, 700km of cables and 30km of pipes.

Means to an end

Over a period of three years, BESIX – in partnership with Larsen and Toubro – has built an impressive amount of 77 tank clusters and buildings structures. Each tank cluster often consisted of several units: 20 pre-sedimentation tanks to capture the settable solids, 16 aeration tanks where oxygen breaks down the contaminants, 12 large diameter clarifiers to separate the biological bacteria from the clean water, etc… All these structures are interconnected by an impressive network of large diameter pipes moving 375,000 tons of water from one treatment unit to the other, 24/7, all year long.

L’ensemble du processus aboutira à la production de biosolides que Dubaï utilisera comme fertilisants et amendements pour les sols dans ses nombreux espaces paysagers : une caractéristique qui démarque la verte Dubaï des autres villes du désert. Ce projet place BESIX dans une position idéale pour remporter de futurs projets de grande ampleur en matière de procédés durables d’épuration des eaux.

Nature-friendly project

One of the more special features is the valorisation of the main by-product from the treatment process, the sludge. This liquid excess product, which is normally disposed of to a landfill in the desert, is anaerobically digested and then dried in state-of-the-art sludge dryers, which use the by-product of the digestion process, methane gas, as fuel to evaporate excess water.

Coordination is key

Apart from the stringent planning and the integration with existing facilities, the key challenge was the day-today coordination between the various trades to assure that interfaces between civil works and the equipment and long piping and electrical cables were correctly and timely planned without the need for costly and time-consuming re-work.