Desalination & Reuse Handbook - Flipbook - Page 36
IDA
WATER SECURITY
HANDBOOK
DJERBA, TUNISIA
The Djerba desalination plant marks a significant step forward for desalination
in Tunisia. It constitutes the first stage of the country’s desalination programme
and creates an important new North African market for the technology.
The design and construction project, executed jointly by Aqualia and GS
Inima, also included the seawater and effluent capture systems, well-water iron
removal plant, product water pumping station, and the installation of pipes
to connect with the existing distribution network (23.7 km of pipelines). The
consortium’s contract with SONEDE also contemplates the commissioning of
the facilities and their management for a period of one year.
Water is drawn from the Mediterranean Sea through an intake located 2.9 km
offshore at a depth of 5 m, and is subjected to dual media and pressure filtration
pretreatment stages. The plant’s two-train RO system operates with a recovery
rate of 46%, using Dow membranes and an ERI energy recovery device. Carbon
dioxide and calcium hydroxide are added to the product water in the posttreatment stage.
SARROCH REFINERY
SWRO, SARDINIA
In January 2018, Acciona Agua commissioned a 12,000 m3/d seawater reverse
osmosis (SWRO) plant at Sarlux’s Sarroch Refinery on the island of Sardinia. The
project was delivered under a BOT contract in which Acciona will operate and
maintain the plant for six years, with the option of a three-year extension. The
project takes screened seawater from a submerged, offshore intake. Pretreatment
includes 125-micron, self-cleaning strainers and UF membrane filtration, after
which seawater undergoes two-pass RO treatment followed by electrodeionisation
(EDI) to polish the water to meet boiler feedwater requirements. The system has
been designed with 97% availability as a modular and largely containerised plant.
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