Desalination technologies
Reverse Osmosis & Thermal Desalination
for drinking water, industrial water & water recycling
WABAG - for over 90 years a synonym for innovative and
successful water engineering solutions.
At present, the widely preferred
technologies for the desalination of
sea and brackish water are:
WABAG is an international supplier of water and wastewater treatment systems for both municipal and industrial segments. It is one
of the innovative leaders in this field and in particular, is one of the
few companies in the world to offer a comprehensive spectrum of
technologies for the desalination of sea and brackish water:
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Membrane technology: reverse osmosis (RO)
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Thermal methods: multi-effect distillation (MED)
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Reverse osmosis
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Thermal desalination (MED, TVC, MED-XL™ and XXL™, MVC,
MSF)
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Electrodialysis (ED)
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Ion exchange (IX)
These technologies can be utilised for both the production of potable water and industrial process water, and form the basis for
optimum and customised solutions. Desalination technologies are
also of increasing importance in the field of water recycling systems and demineralisation, while the employment of membrane
technologies such as reverse osmosis allows the reuse of industrial effluents as highly-purified process water, e.g. as boiler feed
water.
With more than 30 years of desalination experience, WABAG has
designed and built over 100 plants worldwide.
What makes WABAG a preferred partner?
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A comprehensive desalination technology portfolio
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Experience as a desalination plant operator
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Proven process know-how and expertise as well as an understanding of entire systems
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A multinational presence and long-term experience
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The integration of desalination plants with water reclamation
systems
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The provision of complete solutions: EP, EPC, DBO, BOOT
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Freedom of choice on the most suitable membrane systems
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In-house R&D centres in India, Austria and Switzerland, which
guarantee the optimisation and further development of desalination technologies
Finding new approaches through R&D
On the strength of our extensive experience, our current focus is on the development of membrane distillation (MD). Membrane distillation is a thermally powered separation technology
based on hydrophobic membranes, which allows higher concentration efficiency at lower cost.
Pilot tests are currently under way with the aim of studying concentration performance in the
case of various effluents (such as produced water) and brines (such as concentrates from reclamation plant ROs). In this context, the development and design of an ideal pre-treatment for
MD is extremely important.
Moreover, progress has been made in the area of minimising brine return volumes and this
constitutes a step towards zero liquid discharge (ZLD).
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Reverse Osmosis or Thermal Desalination
The larger the salt content of the untreated water and the greater the required degree of purity at the desalination output, the higher
the energy costs.
In the past, reverse osmosis installations required sizeable
amounts of electrical power. However, owing to increased energy
optimisation, these processes have now become far more costefficient. In today’s world, RO is indispensable for the supply of
potable water in countries lacking adequate ground or surface
water resources. It has emerged as the most economic solution
where residual steam is unavailable as an energy source.
By contrast, thermal seawater desalination using residual
steam as an energy source is the most appropriate solution in
power plants and offers major O&M savings. Thermal MED installations, for example, are operated with low pressure exhaust
steam or with output steam from steam turbines. For steam pressures above 2 bar, thermal MSF would then be appropiate. When
such energy is available this process is most suitable.
WABAG is one among the very few companies in the world to offer both technologies on standalone or hybrid basis.
THERMAL
DESALINATION
REVERSE
OSMOSIS
Al Ghubrah, Seawater Intake sinking
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Reverse Osmosis Desalination
RO – the advantages:
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Proven and time-tested technology
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Relatively low investment costs as compared
to thermal methods
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Application flexibility - from very small (< 100
m3/d) to large installations (> 100,000 m3/d)
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No cooling water requirement
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Less energy consumption than with an MED
system
RO is a pressure-driven process. Saline water is
forced through semi-permeable membranes under
pressure, thereby separating the saltwater into a
freshwater stream (known as permeate) and a brine
stream (concentrate).
Typical process steps in an
RO system:
35Al Wasia, Saudi Arabia
Brackish water RO, 200,000 m3/d
1 Pre-treatment (protecting the RO membranes)
2 High Pressure Pumps
3 Energy Recovery system
4 RO Membrane Modules
5 Concentrate discharge
6 Post-treatment (remineralisation, disinfection)
Due consideration
given to the economic
factors such as:
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Energy recovery
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Membrane durability
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Chemical consumption
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Process automation
The recovery percentage of purified water depends upon various factors that include membrane size and internal structure, temperature,
operating pressure and membrane surface area.
Raw water
2
1
4
6
Product water
3
5
Nemmeli, India
Seawater RO, 100,000 m3/d
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Complete and Exclusive
Saving energy & costs
Customized solutions
Employing pressure exchanger systems.
WABAG supplies RO plants for various types of raw water such as
seawater, brackish water and industrial effluents. As a provider of
end to end solutions, WABAG delivers the entire process from the
raw water onwards, including deep seawater intake and outflow
structures to the post-treatment of product water and product
water pumping stations.
The RO process does not require thermal energy, but needs electrical power mainly due to the high pressure pumping required to
obtain flow through the RO membranes. Brine energy recovery
systems have also been optimised in order to reduce energy consumption and have proved to be highly successful.
On the strength of its experience in design, construction and operation of plants of varying sizes, WABAG offers economically advantageous and technically proven solutions for every application.
Highly effective pre-treatment systems are
extremely important
From filtration to micro- and ultrafiltration
WABAG lays a special emphasis on efficient pre-treatment. In
that, apart from conventional filtration technologies, highly effective micro- and ultrafiltration systems are employed.
For example, WABAG designed and built the first plant in Oman
(Duqm, Al Wusta region) to use microfiltration units for pre-treatment and subsequently this successful combination was also
used in the desalination plant for the new Sohar International Port
(start-up 2013), where an in-line RO system was successfully executed.
The Nemmeli RO-drinking water plant in Chennai, which is one of
the largest plants of its kind in India, employs ultrafiltration membranes for highly effective pre-treatment upstream of the RO system.
WABAG is an established name in various pre-treatment technologies.
5 Duqm SWRO, Oman
6,000 m3/d, Pre-treatment (microfiltration)
Al Kharj BWRO, Saudi Arabia
50,000 m3/d, Pre-treatment
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Sohar International Port SWRO, Muscat, Oman
Most modern desalination plant for drinking and industrial water production.
Combination of microfiltration and
reverse osmosis desalination.
Best practice references
An integrated solution.
Client: Contract type:
Commissioning: Majis Industrial Services SAOC
DBO - Design-Build-Operate
2013
Raw water:
Product:
Capacity:
Process: seawater
potable water and process water
20,000 m3/d
reverse osmosis with self-cleaning
filters and membrane pre-treatment
Microfiltration-based Inline RO system reduced CAPEX, OPEX and footprint.
Main parameter:
Plant recovery: Process water quality: Potable water quality: 44,000 ppm TDS
40%
< 25 ppm TDS
120-600 ppm TDS
Completion of a reverse osmosis (RO) based seawater desalination plant producing 8,000 m3/day of industrial process water and
12,000 m3/day of potable water, thus contributing substantially to
a continuous water supply at Sohar Industrial Port Area, Sultanate
of Oman.
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Objectives
Reduced energy consumption
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Ensuring reliable operation even during difficult raw water
intake conditions such as red seawater tides
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Continuous RO water production
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Low life cycle costs
With its hybrid membrane system (high- and low-rejection)
WABAG has met the stringent quality of product water with optimized energy consumption. Energy recovery devices are deployed to extract power from the SWRO reject stream.
Modern design reduces costs
SEAWATER INTAKE SYSTEM
A 2.6 km, 800 mm diameter pipeline feeds the plant through a
tap off from an existing cooling water pump manifold. Two 300
micron automatic self-cleaning filters are installed midway through
the pipeline.
In general terms, the employment of a modern process design
and in particular the direct combination of microfiltration as a pretreatment with reverse osmosis plant without additional cartridge
filters and feeding pumps between MF and RO, has resulted in
lower investment and operational costs. In addition, the plant footprint is smaller than that of conventional RO desalination plants.
PRE-TREATMENT
Microfiltration to handle inlet TSS up to 80 ppm obtaining at the
output SDI of less than 1 (input SDI 35+). Configuration: 7 Skids,
each with 80 modules and 420 m3/h capacity.
DESALINATION
Sea- and brackish water RO – 3 units: 12,000 m3/d, double-stage
Seawater RO – 2 units: 8,000 m3/d, single-stage
Further references
ENERGY RECOVERY SYSTEM
Pressure exchanger
SEAWATER
Muscat, Oman
OPWP Al-Ghubrah: 192,000 m3/d,
potable water, EPC, start-up: 2015
POST-TREATMENT
1. Post-treatment for pH adjustment and disinfection of potable water.
2. Neutralization system for brine.
Ras Laffan, Qatar
PUNJ-LLOYD, 12,000 m3/d,
process water, EP, start up: 2015
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Nemmeli SWRO, Chennai, India
Reverse osmosis to boost drinking water supply volumes.
Clean drinking water for one million
people in Chennai.
Best practice references
A complete solution.
Client: Contract type:
Start-up:
O&M period:
Chennai Metropolitan Water
Supply and Sewerage Board
(CMWSSB)
DBO - Design-Build-Operate
2013
2013-2020
Raw water:
Product:
Capacity:
seawater
potable water
100,000 m3/d
Main parameter:
Plant recovery: Process water quality: Potable water quality: 43,000 ppm TDS
40%
< 25 ppm TDS
120-600 ppm TDS
From the sea to the tap. Using
technological competence and
professional management.
WABAG was awarded a contract for the design, construction and
operational management of one of India‘s largest seawater RO
desalination plants. The plant was built on a 16-hectare site 40
km south of Chennai and converts seawater into fresh potable
water, which is supplied to one million people in the city’s southern
suburbs.
SEAWATER INTAKE SYSTEM
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Pipeline (1,600mm diameter, HDPE, length: 1,050m, sea-side
depth: 14.1m)
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Maritime intake filter
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Intake chamber (upflow filter and sedimentation tank)
PRE-TREATMENT
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Disc filters, ultrafiltration
ENERGY RECOVERY SYSTEM
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Pressure exchanger
DESALINATION
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Reverse osmosis (spiral-wound polyamide)
POST-TREATMENT
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Remineralisation system: carbon dioxide absorber and limestone filter
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Degasser tower
Further references
BRACKISH WATER
Al Wasia, Saudi Arabia: 200,000 m3/d,
potable water, start-up: 2010
Al Kharj Saudi Arabia:
50,000 m3/d, potable water,
start-up: 2009
SEAWATER
Duqm, Oman: 6,000 m3/d,
potable and process water,
DBO, start-up: 2010
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RO for water recycling at the Panipat Refinery, India
Closing the water cycle.
Highly efficient water recycling plant
for a refinery expansion.
Best practice references
A sustainable solution.
Client: Indian Oil Corporation Ltd. (IOCL)
Start-up: 2006
Raw water:
secondary refinery effluent and
various refinery/petrochemical
process effluents
Product:
boiler feed water and process
water for PTA production
Capacity:
21,600 m³/day
Technology: Plant:
multi-stage treatment including
ultrafiltration and reverse osmosis
water recycling plant
Main parameter:
Plant recovery: TDS: 1,786 mg/l, silica: 98 mg/l,
COD: 150 mg/l
90%
WATER QUALITY
after RO: TDS: 12 mg/l
silica: 0.09 mg/l
COD: 0
after demineralisation:
TDS: < 0.05 mg/l
silica: 0.007 mg/l
Further references
Paradip Refinery, Orissa, India:
54,000 m3/d, process water, start-up: 2015
Panipat Naphta Cracker Project, India:
20,900 m3/d,
boiler feed water,
start-up: 2009
90% water recovery.
Essar Oil, India:
9,600 m3/d, cooling and
boiler feed water,
start-up: 2011
Completion of a tertiary treatment plant (TTP) for the refinery effluent recycling for the Indian Oil Corporation Ltd., in Panipat, India with the aim of achieving zero liquid discharge in combination
with the recycling of wastewater for reuse as boiler feed make-up
water. It is the first plant of its kind in India.
Sustained focus on zero liquid
discharge (ZLD).
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High-rate clarification
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Pressure sand filtration
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Ultrafiltration (UF) – pressure-driven, hollow fibre system
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Cartridge filter
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Reverse osmosis (RO) – two-pass system in combination with
a brine concentrator, 3 stages
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Degasser tower
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Demineralisation: RO permeate is polished by mixed bed, ion
exchange filters
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Thermal Desalination technologies
Multi-effect distillation
Thermal desalination (multi-effect distillation) takes place in a series of vessels
(effects) in which the principle of condensation and evaporation at reduced
ambient pressure is applied. This permits the saline water to undergo boiling
without the need to supply additional
heat after the first effect.
Thermal desalination
– the advantages
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Stable and proven process
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Minimal or no need for pre-treatment
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High output water purity level
(≤ 10 ppm TDS)
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Ideal in combination with power
plants
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Simple operation with low maintenance costs
Achieving synergy MED
MED-TVC - enhanced
efficiency
The MED desalination process is
normally used for medium-sized
and large-scale thermal desalination plants where thermal energy is
available in the form of low-pressure
steam (≥ 0.3 bar abs.) or waste heat,
e.g. in combination with thermal
power plants or industrial complexes.
It therefore represents the most economic distillation process from an energy efficiency perspective.
Standard MED plants are equipped with
thermal vapour compressors for enhanced
efficiency.
Main advantages
Therefore, from cost-efficiency standpoint,
TVC distillation is the most advantageous,
steam-heated process for medium-sized
plants.
The MED process operates at low
temperatures with high thermal efficiency, providing:
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Low thermal energy consumption
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Low operating costs
Selected references
As a rule, the TVC desalination process is
employed for small to large-scale thermal
desalination plants where thermal energy
in the form of medium pressure steam
(>3 bar) is available, e.g. in combination
with thermal power plants or industrial
complexes and this results in low operational and investment costs.
Main advantages
The TVC process operates at low temperatures with high thermal efficiency, providing:
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Small to large train sizes
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Low investment costs
AVR, Rotterdam, The
Netherlands: 24,000 m3/d,
process water
CMI, Marmara, Turkey:
3,360 m3/d, process water
Selected references
Tobruk, Libya: 13,333 m3/d, potable water,
start-up. 2016
Suralaya, Indonesia: 6,000 m3/d, process &
potable water, start-up: 2010
Rembang, Indonesia: 6,000 m3/d, process &
potable water, start-up: 2010
GMDC, Kutch, Gujarat, India: 2,400 m3/d,
process water, start-up: 2006
Benghazi North, Libya: 4,800 m3/d, process
water, start-up: 2005
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MED-MVC - the
stand-alone solution
Where an external steam source is
unavailable for heating, standard MED
plants are equipped with mechanical
vapour compressors (MVC). These provide heat for water evaporation through
mechanical steam compression.
The MED-MVC desalination process
is normally used for small to medium
scale thermal desalination plants where
thermal energy is unobtainable. The
mechanical compressor is electrically or
diesel driven.
Main advantages
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No need for external thermal energy
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A robust process
Multi-stage flash
(MSF) - large-scale
thermal desalination
technology
MSF - the big solution. The MSF desalination process is utilised mainly for
large-scale, thermal desalination plants
where thermal energy in the form of
low-pressure steam (>2 bar) is available, e.g. in combination with thermal
power plants or industrial complexes.
Saline water is heated by steam and
then fed into a series of vessels (effects)
where reduced pressure leads to immediate boiling (flash) without the need for
additional heat.
Main advantages
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Large train sizes
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Low energy consumption
Selected references
Burrup Penninsula, Australia:
3,600 m3/d, process & potable
water
CHP, Taba, Egypt:
2,000 m3/d,
potable water
Selected references
REFURBISHMENTS
Khoms, Libya: 30,000 3/d,
process water, start-up: 2008
Zliten, Libya: 30,000 m3/d,
potable and process water,
start-up: 2008
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MED – XL™ and
XXL™
Recently, the capacity of thermal seawater desalination units has begun
to increase considerably. In response
to this trend, WABAG has designed
and optimised its XL (in the range of
13,500 - 25,000 m3/d) and XXL units
(from 25,000 up to 45,000 m3/d).
In these newly developed systems,
all the preheaters are enclosed in an
extremely compact manner, which not
only prevents heat losses, but also
guarantees highly efficient operations.
These large units can be built as
MEDs or MEDs with thermal vapour
compressors (MED-TVC).
WABAG offers sustainable solutions for:
Operations & Maintenance
(DBO, BOT, BOOT)
After Sales Services
n Drinking water treatment
Conceptualizing
n Industrial and process water treatment
Commissioning
n Water reclamation
n Sea and brackish water desalination
Financing
n Municipal wastewater treatment
n Industrial wastewater treatment
n Sludge treatment
Construction
WABAG is one of the world’s most innovative water
Design
treatment companies with know-how in specific technologies and in-house developed processes such as:
n Biofiltration BIOPUR®
n Moving bed biology FLUOPUR®
n Activated sludge Hybrid™, SBR,
processes MICROPUR-CAS®
n Membrane bioreactor MARAPUR®,
MICROPUR-MBR®
n Membrane filtration
RO, MF, UF, NF
CERAMOPUR®,
CERAMOZONE®
n Denitrification BIODEN®, ENR®
n Oxidation processes
ADOX®, BIOZONE®
n Adsorption processes CARBOPUR®, PACOPUR®
n Thermal desalination MED, TVC, MVC, MSF
MED XXL™
n Fine sieving
MICROPUR®
n Deep bed filtration in various designs
n Anaerobic sludge digestion
including advanced energy recovery
Equipment supply
Engineering
WABAG Vienna
WABAG Chennai
Headquarters
The WABAG Group represents a leading multinational
player with companies and offices in 20 countries and
a focus on emerging markets in Eastern Europe, Africa,
LATAM, Middle East, South East Asia, China and India.
sustainable solutions. for a better life.
VA TECH WABAG LIMITED
“WABAG House“
No.17, 200 Feet Thoraipakkam –
Pallavaram Main Road
Sunnambu Kolathur
Chennai 600 117, India
Tel.: +91-44-3923 2323
[email protected]
VA TECH WABAG GmbH
Dresdner Straße 87-91
1200 Vienna,
Austria
Tel.: +43 1 251 05 0
[email protected]
www.wabag.com