Desalination as a sustainable alternative for water supply case studies.

July 2007
AMTA Annual Conference & Exposition
San Diego, CA – July 12-15, 2010
AMTAAnnual Conference & Exposition
America’s Authority in Membrane Technology 1
DESALINATION AS A SUSTAINABLE
ALTERNATIVE FOR WATER SUPPLY:
CASE STUDIES.
Jorge J. Malfeito
Acciona Agua S.A.U.

America’s Authority in Membrane Technology
Right bank of the river Gorgos.
At 2 km from the river mouth.
JAVEA DESALINATION PLANT
LOCATION

Intake …………………………………….. ……… Beach wells ( 200 m
)
Raw water salinity …………………………….. 38 ( ups )
Elements ………………………………….. ……..8040 Spiral wound
Nº of racks …………………………………. ……4
Future racks …………………………………… ..6
Permeate flow per rack ……………………… 7.000 m3 / day
Total permeate flow ………………. …….. .…28.000 m3 / día
Future permeate flow after extension …... 42.000 m3 / día
Nº of stages ………………………………………… 1
Recovery ………………………………... …………45 %
Permeate salinity ………………………………. < 400 mg/l
Final use of the permeate water …………… Drinking water
Salinity of the brine ………………. …………..68 ( ups )
PLANT DESCRIPTION

SCHEME OF THE PLANT

REVERSE OSMOSIS
Pre-treatedwater Permeatewater
Brine
Split chamber pumps
655 m3/h
69 bar
Pelton turbines:
360 m3/h
66 bar
Operational engines:
1100 kw
6.000 W

Lime and CO2 tanks.
Treated water pumping station.
POST-TREATMENT

BRINE DISCHARGE OPTIONS
Option 1: Gorgos river mouth.
Advantage: Strong hydrodynamics.
Disadvantage: Posidonia oceanica
meadows at 80 m from the mouth
Option 2: La Fontana Channel
Stagnant water channel.
Lack of dissolved oxygen: Anaerobic
fermentation
In summer the T was 5-7 degrees higher
than the sea water. High level of evaporation.
Posidonia oceanica meadows at 400 m from
the mouth.

BRINE DISCHARGE

SCHEME OF THE BRINE DILUTION SYSTEM
BRINE DISCHARGE

RESULTS
 Discharge water conductivity (μScm-1).
 Permeate water (μS cm-1).
 pH
Temperature (ºC).
Salinity of the discharge (psu).
Data of the discharged water

Surface water salinity
RESULTS

RESULTS
Interstitial water salinity

RESULTS
Bottom water salinity

CONCLUSIONS
The salinity of the effluent in the Channel of the Fontana it is always around
the seawater salinity values.
Outside the channel, the extension of the area affected by the discharge is
usually very reduced (summer) or null (winter).
In the superficial waters we can observed a total dilution, while the salinity
effects in the bottom can be detected until 300 meters from the outlet of the
channel.
Recovered for recreational uses (no anoxia and its associate problems).

17
THAMES GATEWAY DESALINATION PROJECT
VARIABILITY OF THE RAW WATER:
Surface and seawater mixture.
Flexibility of the plant design.

18
Salinity: From 5 to
20 g/l (average 12,5
g/l).
Temperature from
5 to 25 ºC.
TOC from 0 to 10
mg/l.
RAW WATER CHARACTERISTICS
0
2000
4000
6000
8000
10000
12000
14000
0 5 10 15 20 25 30
temperature (oC)
TDS(mg/l)
TDS and temperature design envelope (abstraction period 3 hours prior to
low tide):

PLANT DESIGN

20
PLANT DESIGN

21
Design
Highest recovery.
Minimize the energy consumption.
Hydraulic and electrical energy recovery.
Construction
Materials reuse.
Operation
Intermitent raw water abstraction (lowest
salinity).
Minimization of the environmental impact.
Fishes.
Brine.
SOSTENIBILITY CRITERIA

22
Peak power 17.6 MW.
Annual average power 14 MW (2.27 kWh/m3).
The plant will be powered by renewable energy provided by five 1.6
MW bio-diesel engines. The bio-diesel will be derived from a
sustainable feedstock, and the client is currently evaluating the use of
used cooking oils as a source of energy.
Breakdown of power consumption across the plant.
ENERGY CONSUMPTION
8%Other
9%Final Water pumping
61%RO
15%Pre-treatment process
7%Raw water abstraction and storage
Percentage of total power consumptionProject component
8%Other
9%Final Water pumping
61%RO
15%Pre-treatment process
7%Raw water abstraction and storage
Percentage of total power consumptionProject component

23
The high storage capacity of the salinity buffer tank means that raw water
abstraction can be targeted towards minimizing the salinity of the raw water on
each tidal cycle, and hence the specific energy consumption of the RO process
increasing demand for water.
Using variable speed drives on the four stages of RO feed pumps reduces
energy wastage through permeate throttling.
The use of Pelton turbines to recover energy from the reject stream. Because
of the delays to the project Pelton Turbines were at the time of selection the
proven technology for large scale RO plants. Pressure or work exchangers could
reduce specific power further.
MEASURES INCLUDED TO MINIMIZE THE
SPECIFIC ENERGY CONSUMPTION

24
Innovative electrical engineering :
(he use of higher voltage transmission, water cooled switch gear,
and intelligent assemblies, which monitor electrical energy use and
efficiency to switch off non-essential power use during peak demands,
and optimize running plant to the most efficient available.
MEASURES INCLUDED TO MINIMIZE THE
SPECIFIC ENERGY CONSUMPTION
Ene Feb Mar Abr May Jun Jul Ago Sep Oct Nov Dic
0
50
100
150
200
250
300
350
400
450
500
550
600
650
ConsumoeléctricokW
Mes
Refrigeracion por aire Refrigeracion por agua

25
MATERIALS REUSE

26
145.000 m3 dehydrated sludge
reused.
33.000 m3 structures reused.
MATERIALS REUSE

27
 C. E. de Biodiesel
 Intake
 Brine discharge
MATERIALS REUSE

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Objective:
Low activity of the river species.
To get lower raw water salinity.
Method:
Abstraction from river during 3 hour window
per tidal cycle reduces mean raw water salinity.
Crayfish
Seahorse
Dan Sprawson/Zsl
INTERMITENT WATER ABSTRACTION

29
Objective
To drive off the fishes.
To expel the larvaes.
Method:
Acoustic fish deterrents operate
prior to and during the period of
abstraction (140 Db).
Air flushing before the start up.
3 mm screens.
PROTECTING THE RIVER WILDLIFE

Desalination as a sustainable alternative for water supply case studies.

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