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WABAG offers sustained solutions for special customer needs through a comprehensive range of services and innovative technologies.

Drinking Water Treatment

Sundarijal Water Treatment Plant

Kathmandu Valley, Nepal

Client

MelamchiWater Supply Development Board

Location

Melamchi, Kathmandu, Nepal

Capacity

85,000 m 3/d

Nepal’s largest state-of-the-art drinking water treatment plant to ensure safe drinking water for over one million people of Kathmandu Valley. The project was funded by JICA.

Project Highlights

  • Turn-key execution
  • Flocculation –Sedimentation –Filtration
  • Underground clear water reservoir
  • 2 x 100 KW axial flow mini hydro turbine power generator
  • Disinfection by chlorination
  • SCADA and Control room operation

Upper Ruvu Water Treatment Plant

Mlandizi, Tanzania

 

Client

Dar Es Salaam Water & Sewerage Authority (DAWASA)

Location

Dar Es Salaam, Mlandizi, Tanzania

Capacity

200,000 m3/d

Rehabilitation and expansion of the intake and raw water transmission system at Ruvu river and the building of a new water treatment plant to cater over 700,000 people in Dar Es Salaam. The project was funded by EXIM India.

Project Highlights

  • Turn-key execution
  • Flow division
  • Flocculation Turbidity removal
  • Coagulation
  • Solid contact clarification
  • Disinfection using chlorination

Putatan Water Treatment Plant

Philippines

 

Client

Maynilad Water Services Inc

Location

Metro Manila, Philippines

Capacity

150,000 m3/d

State of the art treatment plant treating complex source water and producing highest quality drinking water.

Project Highlights

  • Turn-key execution
  • Biological Aerated Filtration (BAF – WABAG System) including innovative drainage filter system
  • Raw Water Pumping Station
  • Ultrafiltration for additional 50,000 m3/d
  • Dissolved Air Flotation (DAF)

Muttenz Water Treatment Plant

Switzerland

 

Client

Municipality of Muttenz

Location

Muttenz, Switzerland

Capacity

19,200 m3/d

Path breaking technology for the elimination of micropollutants in groundwater.

Project Highlights

  • Advanced Oxidation (AOP) – System HiPOx
  • Granulated Activated Carbon (GAC) filter and Dosing of Powdered Activated Carbon (PAC)
  • PAC Recycling System
  • Ultrafiltration
  • Back-washwater treatment

Panjrapur Water Treatment Plant

Panjrapur, Maharashtra, India

Client

Municipal Corporation of Brihanmumbai

Location

Panjrapur, Maharashtra, India

Capacity

455,000 m3/d

One of the largest drinking water treatment plants in India employing state of the art technologies to reduce footprint and enhance efficiency.

Project Highlights

  • Inlet chamber
  • Flash mixing
  • Flocculation
  • Lamella clarification
  • Rapid Gravity Sand
  • Filtration
  • Chlorination
  • Recirculation tank

Al Ghubrah SWRO

Muscat, Oman

Client

Muscat City Desalination Company SAOG (MCDC)

Location

Muscat, Oman

Capacity

191,000 m3/d

Largest Plant in the heart of Muscat with innovative “arrow head” design for pre-treatment, thus reducing footprint in a congested space & catering to over 5 lakh people.

Project Highlights

  • Subsea Intake pipeline for best water quality
  • Red Tide insurance using DAF – DMF Pre-treatment
  • One of the largest skid capacities at 27,200 m3/day
  • Two pass RO system with latest Q-series from ERI system
  • Standby RO skid for high plant availability

Nemmeli SWRO

Chennai, India

 

Client

Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB)

Location

Nemmeli, Chennai, India

Capacity

110,000 m3/d

State-of-the-art desalination plant and a reliable drinking water source for Chennai, contributing to 12.5% of daily supply and catering to over 1.5 million of population.

Project Highlights

  • Ensuring efficient and reliable plant operation despite varying seawater parameters
  • Optimal lifecycle cost
  • Low area footprint
  • Energy recovery models ensuring reduced power consumption

Al Wasia BWRO

Saudi Arabia

 

Client

AZIZ Company Ltd. (for Ministry of Agriculture)

Location

Al Wasia, Saudi Arabia

Capacity

200,000 m3/d

One of the largest desalination plants for brackish water treatment. The plant supplies up to 200,000 m3/d to a growing population in Riyadh, which is roughly 100 km away.

Project Highlights

  • Successful Refurbishment & Upgrade of existing plant
  • Desalination by use of slow decarbonisation and reverse osmosis

Duqm SWRO

Al Wusta, Oman

 

Client

Rural Areas Electricity Company (RAECO)

Location

Al Wusta, Sultanate of Oman

Capacity

6,000 m3/d

The plant, which has capacity of 3 x 2,000 m3 per day provides both drinking water for the local population and a small amount of utility water for a power station.

Project Highlights

  • Open seawater intake system
  • First plant in Oman to use microfiltration units for pre‐treatment
  • Capacity enhancement by 2,000 m3 & successful O&M by WABAG

Tobruk MED

Libya

 

Client

GDCOL

Location

Tobruk, Libya

Capacity

13,333 m3/d

The thermal sea water desalination plant using MED-TVC technology will ensure continuous supply of clean drinking water to a large population.

Project Highlights

  • Pre-heating of raw-water
  • Evaporation
  • Condensation
  • Potabilisation
  • Model for realizing further projects in terms of securing financing

Rembang MED

Rembang, Indonesia

Client

PT Perusahaan Listrik Negara (Persero)

Location

Jawa Tengah, Rembang, Indonesia

Capacity

2 x 3,000 m3/d

The thermal desalination plant, type MED-TVC, ensures a continuous water supply for the nearby power plant (630 MWe)

Project Highlights

  • Reliable operation even when using varying sea water
  • Safe compliance with required product quality
  • Reduction of operation costs
  • Law impact to the environment

Oran WWTP

Oran, Algeria

Client

DHW Oran

Location

Oran, Algeria

Capacity

270,100 m3/d

Turnkey realisation of Algeria’s largest municipal WWTP. Design-Build-Operate (2 years O&M)

Project Highlights

  • Mechanical pre-treatment
  • Activated sludge treatment: aeration and secondary settling
  • Tertiary treatment: disinfection with chlorine
  • Sludge treatment line: thickening, anaerobic digestion, dewatering

Kondli WWTP

Delhi, India

 

Client

Delhi Jal Board (DJB)

Location

Kondli, Delhi, India

Capacity

204,500 m3/d

The largest WWTP in New Delhi with complete automation system using PLC software and controlled by central control room.

Project Highlights

  • Design-Build-Operate
  • Mechanical/biological WWTP
  • Activated sludge process
  • Anaerobic sludge treatment & biogas utilization for energy production

POLATLI WWTP

Turkey

 

Client

Ministry of Environment and Urbanization

Location

Polatli, Turkey

Capacity

19,872 m3/d (stage 1)

Co-financed by European Union with treatment standards conforming to EU regulations.

Project Highlights

  • Mechanical/biological treatment providing carbon and nitrogen removal
  • Turnkey execution – WWTP & sewerage network and collectors

PORT SAID WWTP

Egypt

Client

SAMCO (NSPO)

Location

Port Said, Egypt

Capacity

40,000 m3/d, peak flow 107,000 m3/d

The multi-stage treatment offers water reuse for landscaping and irrigation. Executed on DBO-scheme including 12 months O&M.

Project Highlights

  • Mechanical pre-treatment
  • Biological treatment – SBR (Sequencing Batch Reactor) process with extended aeration for aerobic sludge stabilization
  • Disc filters
  • Disinfection
  • Sludge thickening and drying

SAARNERATAL WWTP

Alpnach Switzerland

 

Client

Entsorgungszweckverband Obwalden

Location

Alpnach, Switzerland

Capacity

14,000 m3/d

Employing Aerobic Granular Activated Sludge Technology – representing the first NEREDA® plant in Switzerland

Project Highlights

  • Reduced footprint (-34%)
  • Reduced volume (-40%)
  • Higher nitrogen removal in spite of the reduced volume

DONA IMELDA WWTP

Philippines

Client

Maynilad Water Services, Inc.

Location

Metro Manila, Philippines

Capacity

6,000 m3/d, peak flow 10,800 m3/d

High performance on limited space. The WABAG FLUOPUR® process provides smaller footprint solutions for carbonaceous nitrification with lower capital and operating costs. Design-Build-Operate (24 months O&M).

Project Highlights

  • Screening
  • De-gritting
  • Mixed bed bio-reactor (MBBR -FLUOPUR)
  • Flash mixing
  • Flocculation
  • Sedimentation
  • Disinfection
  • Sludge thickening and dewatering
  • Odour treatment by pre-scrubber and biofilter

ZERMATT WWTP

Switzerland

Client

City of Zermatt

Location

Zermatt, Switzerland

Capacity

60,000 m3/d

Underground MBR for ski tourism region, largest MBR plant in Switzerland. Rehabilitation and upgrade of existing WWTP to more stringent effluent standards and for dealing with tourism-related peak loads ranging between 6,000 and 60,000 PE. The complete plant is housed in mountain caverns at a depth of up to 200m.

Project Highlights

  • Mechanical pre-treatment
  • Wastewater lifting
  • Coagulation
  • Primary sedimentation
  • Fine screen
  • Membrane filtration in separate basin
  • Neutralisation
  • Phosphorus elimination by pre and simultaneous precipitation

Kodungaiyur WWTP

Chennai, India

 

Client

Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB)

Location

Kodungaiyur, Chennai, India

Capacity

110,000 m3/d

Kodungaiyur Plant, executed on DBO model, stands as the role model plant in India for “comprehensive sewage treatment” which focuses on resource recovery with the conviction that “Sewage is a resource, not a liability. The plant is equipped with an advanced sludge management process which is capable of producing adequate amount of electricity to run the entire plant.

Project Highlights

  • Mechanical/biological WWTP
  • Anaerobic sludge treatment & biogas utilization for energy production
  • First in India to achieve 90,000 operating hours from a single gas engine
  • Enables reuse of treated water in nearby refinery

Sanliurfa WWTP

Turkey

 

Client

Ministry of the Environment and Urbanisation

Location

Sanliurfa, Turkey

Capacity

144,833 m3/d

Co-financed by EU, a stand out reference in terms of reduced area footprint as well as operating expenditure

Project Highlights

  • Turn-key construction of large scale WWTP
  • Activated sludge process & Anaerobic sludge digestion
  • Energy-neutral – 95% self-sufficiency by use of biogas
  • One of the largest solar sludge drying units, providing savings in opex
  • Energy savings by gravitational flow of wastewater

Tehran Southern WWTP

Iran

 

Client

Tehran Sewerage Company (TSC)

Location

Tehran, Iran

Capacity

450,000 m3/d

A resource-protective wastewater treatment plant for the city of Tehran. The plant is energy-neutral by use of biogas and the purified water is reused for agricultural irrigation. The plant, which covers 4 water lines & 6 sludge treatment lines, was built on DBO-scheme and was operated by WABAG for a period of 3.5 years.

Project Highlights

  • Turn-key construction of one of the large scale WWTP
  • Activated sludge process & Anaerobic sludge digestion
  • Energy-neutral – >80% self-sufficiency by use of biogas
  • Process design enables water reuse for agricultural irrigation

Xianghomen WWTP

China

 

Client

Beijing Drainage Group Co., Ltd

Location

Beijing, China

Capacity

WWTP: 600,000 m3/d, Sludge digester volume: 5 x 12,000 m3

Turnkey plant with advanced technology for anaerobic sludge treatment and biogas utilisation for one of China’s largest municipal wastewater treatment plants. The plant produces 67,000 kWh/d.

Project Highlights

  • Sludge storage tanks for primary and excess sludge
  • Thickening
  • Anaerobic sludge digestion
  • Dewatering
  • P-removal system for sludge dewatering
  • Biogas treatment and storage system
  • Air blower station with biogas utilization
  • Boiler room with biogas utilization

City Wastewater Management

Istanbul, Turkey

Client

Istanbul Water and Sewerage Corporation (ISKI)

Location

Istanbul, Turkey

Capacity

24 x 7 management of the wastewater of 16 million inhabitants – on 2 continents.

Project Highlights

  • Integrated Management Model- Maintaining over 120 units
  • 9 pre-treatment plants: 4,200,000 m3/d
  • 52 biological wastewater treatment plants: 980,000 m3/d
  • 64 pumping stations: 2,300,000 m3/d

3 main WWTPs clean the bulk of the city’s wastewater volume based on energy-optimized designs.

Integrated Water Management

Chennai, India

Client

Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB)

Location

Chennai, India

Capacity

Sustaining the water supply of Chennai through efficient operational management of drinking water and wastewater treatment plants for over a decade.

Project Highlights

  • Ensuring water security & enhanced sanitation coverage for Chennai
  • 2 Drinking Water Treatment plants: Red Hills and Veranam (480, 000 m3/d)
  • 2 Power neutral STPs (Kodungaiyur & Perungudi) and 1 WWTP (Alandur): 188,000 m3/d
  • 1 SWRO Plant (Nemmeli): 110,000 m3/d

City Water Management

Mersin, Turkey

Client

Mersin Belediyesi Su Ve Kanalizasyon Idaresi (MESKİ) Genel Müdürlüğü

Location

Mersin, Turkey

Capacity

Providing professional water services for a city comprising 1.4 million people.

Project Highlights

  • Environmentally compatible wastewater treatment to protect the Mediterranean Sea
  • Karaduvar WWTP: 189,523 m3/d
  • Tarsus WWTP: 61,272 m3/d
  • 5 small WWTPs 1,000 -12,300 m3/d
  • A safe drinking water supply for one million people
  • Berdan WTP: 390,000 m3/d

Coloane WWTP

Macao, China

Client

Government of the Macau Special Administrative Region

Location

Macao, China

Capacity

130,000 m3/d

Operation & Maintenance of the 130,000 m3/d municipal WWTP based on the SBR-process. Ongoing O&M since December 2008 including technical plant adaptation works.

Scope:

WABAG is responsible for the operations, maintenance and repair of the entire plant, including all equipment as well as provision of chemicals and energy.

Water and Wastewater Management

Delhi, India

 

Client

Delhi Jal Board (DJB)

Location

Delhi, India

Capacity

Ensuring water security and improving sanitation for Delhi through efficient operation and maintenance of drinking water and wastewater treatment plants.

Project Highlights

  • Promoting innovative models to enhance efficiency and resource recovery
  • 1 Drinking Water Treatment plants (Dwaraka): 220, 000 m3/d
  • 3 WWTP (Kondli, Papankalan & Keshopur): 525,000 m3/d
  • 1 Sewage Pumping Station (Possangipir): 41,639 m3/d

AMAS WWTP

Bahrain

Client

Ministry of Housing

Location

Al Madina Al Shamaliya, Bahrain

Capacity

40,000 m3/d

Building a state of the art WWTP for a new township located on reclaimed land in Bahrain. Purified water will be reused to cater for the entire irrigation water requirements for all 13 islands.

Project Highlights

  • Highly challenging civil component on reclaimed area
  • Mechanical pre-treatment
  • Biological treatment
  • Wastewater filtration
  • Sludge treatment

Beni Messous WWTP

Algeria

Client

Direction de l’hydraulique de la Wilaya d’Alger

Location

Beni Messous, Algeria

Capacity

35,770 m3/d

Two wastewater treatment lines followed by a common tertiary treatment plant (5,500 m3/h) for water reuse for agricultural irrigation.

Project Highlights

  • Mechanical pre-treatment
  • Biological treatment
  • Wastewater filtration
  • Final disinfection odour treatment
  • Sludge treatment: aerobic digestion, dewatering

Madinaty WWTP

Egypt

 

Client

Arab Company for Projects and Urban Development A.R.

Location

Near Cairo, Egypt

Capacity

40,000 m3/d

Water reclamation plant for a new and exclusive satellite city near Cairo. Purified water is directly pumped into a special service water network for irrigation purposes. DBO-contract incl. 12 months O&M.

Project Highlights

  • Mechanical pre-treatment
  • Biological treatment
  • Wastewater filtration
  • Final disinfection
  • Sludge treatment: aerobic digestion, dewatering

The new Goreangab WTP

Windhoek, Namibia

 

Client

City of Windhoek

Location

Windhoek, Namibia

Capacity

21,000 m3/d

Turning municipal wastewater into drinking water. World’s first advanced water treatment plant for direct potable water reuse.

Project Highlights

  • Pre-ozonation
  • Coagulation & flocculation
  • Dissolved air flotation (DAF)
  • Dual media filtration
  • Main ozonation
  • Biologically activated carbon filter
  • Adsorption/ activated activated carbon filter (GAC)
  • Ultrafiltration

Madinat Salman WWTP – Sustainable wastewater model for a rapidly growing Bahrain

Wastewater Infrastructure – A necessity to bolster sustainable growth in GCC

In recent years, Bahrain has proved itself to be a front runner in the quest for development not only in the Middle East but the entire globe. Considered one of the best places to reside in the world, it is home to a plethora of developmental projects. The spectacular water front of Bay of Bahrain , the modern city of Diyar-Al-Muharraq or the Bahrain monorail are only some of the manifestations of a nation growing rapidly. With the major chunk of its GDP arising from the services sector, Bahrain is an important economic hub in the GCC which characterises itself with high ease of doing business and a welcoming immigration policy.

This favorable business and social environment attracts people from all across the globe. In addition to the immigrants, Bahrain’s own population is close to 1.3 million housed in an area of 710 sq. kms. This denotes one of the highest population density rates in the world, projected to grow at a rate of 4.6% annually.

Effectively sustaining this population while maintaining their quality of life makes efficient water management the need of the hour. Water management includes not only water treatment for one time consumption but a holistic approach including provision of necessary treatment of the resulting wastewater. This approach should also be augmented with a provision of water recycling to round off the water cycle.

This utopian idea of holistic wastewater management is being put to implementation at Bahrain in the form of the 40,000 m3 per day WWTP of Madinat Salman.

The Madinat Salman Plant: A Technological Marvel

The Engineering, Procurement & Construction of the plant was awarded to VA Tech Wabag in collaboration with Belhasa projects. The scope of the order award also includes 5 years of O&M.

The site is built on 13 islands of reclaimed land which accounts to 750 hectares of total plant area.

21 m deep terminal lift pumping station:

The process scheme begins with the inlet chamber and an 85,000 m3 per day terminal lift pumping station which sits at a depth of 21 metres. The water from the deep sewage gravity network is pumped through this depth with the help of a dry well pump.

Efficient Reuse & Resource Recovery

The heart of the plant is the tertiary treatment which renders it further purity through disc filters and disinfection using chlorination. The plant runs on the philosophy of resource recovery for the environment to the maximum extent. The collected sewage is digested, thermally dried and bagged through an automatic bagging plant for sale to farmers as manure.

WABAG- Setting new standards in execution

Executing this project was a huge challenge as it was situated on reclaimed land surrounded by sea from 3 sides and a hill in the middle which proved to be a bottle neck for construction.

The project stands out as a structural marvel with 25,000 cubic meters of concreting and reinforcement of over 7,000 MT of steel. The 85,000 m3 per day deep terminal lift pumping station sits over 160 piles carefully inserted over an unstable surface which housed an aquifer below it.

The 4.5 km long outfall pipeline which rounds off the plant process involved both onshore and offshore HDPE piping of 1200 mm diameter. The offshore piping involved plastic welding of numerous sections of length 1.5 resulting in two huge portions of 750 meters each. Both these portions were tugged to the ocean and systematically sunk into trenches made using specialized sea water dredging machines.

Despite all these challenges, no compromise was made on safety and quality. With an eye for customer satisfaction, Wabag overcame these challenges and completed the project on time, clocking a total of 3.5 million safe man hours. Wabag was also commended for the hydro-testing and commissioning which was successfully completed in the first go itself.

Effect on people’s lives and the future of Reuse

The project touches the lives of almost 100,000 civilians as it promotes water sustainability with a potential to reclaim water from sewage at the city of Madinat Salman in the rapidly growing kingdom of Bahrain. The plant is a showcase model and proposes a fitting solution to the wastewater treatment needs of not only Bahrain but the entire GCC region as such.

Kodungaiyur power neutral plant: converting waste to wealth

Initial state

North Chennai has historically been the hub for manufacturing activities and in the last decade, is considered an area of stagnant growth with a sizeable and burgeoning population.

However, due to inadequate wastewater management infrastructure, the exploding population which is labour oriented started facing a lot of health and environment issues. This was hampering the productivity of the population and the economic progress of the region.

Challenges

Development of a sustainable wastewater infrastructure for North Chennai which will ensure the safe discharge of treated sewage after removal of the contaminants for replenishing the nearby water bodies.

The solution

Chennai Metro Water Supply and Sewage Board decided to set up a first of its kind sewage treatment plant at Kodungaiyur and VA Tech WABAG was entrusted with the turnkey realization of a new biological sewage treatment plant being the reliable and trusted partner of CMWSSB for developing sustainable water infrastructure.

The contract assigned to VA TECH WABAG was on Design-Build-Operate mode in the year 2003 and was successfully commissioned in the year 2006 with a capacity of treating 110 million liters of sewage per day.

Technologies

The entire plant operates in two different stages. The first stage ensures safe discharge of treated sewage through an aerobic process. Whereas in the stage phase the sludge is treated through an advanced anaerobic process to generate green power from bio-gas and thus makes the plant power neutral, i.e. on self-sustaining basis without depending on grid power.

The plant handles 110 MLD (million liters per day) of sewage and the treatment process is based on activated sludge process with anaerobic sludge digestion and biogas utilisation by means of a power plant based on gas engine (capacity 1,317 KVA). After commissioning in 2006, WABAG also assumed responsibility for operations & maintenance of the plant for over a period of 12 years. It is the largest plant of its kind in India and the most energy efficient one among the 9 STPs in Chennai – achieving 98% self-sufficiency in terms of power consumption.

Comprehensive technical and economic know-how of WABAG has guaranteed efficient project realization and a highly commendable operations phase of the plant for over a decade. The Kodungaiyur STP has the distinction of completing maximum hours of run time with a single gas engine, which has run successfully for over 90,000 operating hours with producing over 50,000 MWh over the last 12 years.

In line with Govt. Policies

  • MNRE (Ministry for New and Renewable Energy) programme offering subsidy to utilities and operators for setting up green power generation units inside WWTPs
  • CPCB (Central Pollution Control Board) circular to all SPCBs (State Pollution Control Boards) mandating green power production from methane present in biogas produced through anaerobic digestion of sludge
  • India’s ratification at COP 21 Paris Climate Convention to satisfy 40% of its energy requirements from non-fossil sources to reduce carbon emission

Key Highlights

  • One of the largest Power Neutral Plant of India and achieves 98% self-sufficiency in terms of power consumption.
  • Enables reuse of treated wastewater to reduce the burden on freshwater- relevant especially in a city like Chennai which depends on groundwater. Supplies 21 MLD of Treated Sewage to nearby Chennai Petro Chemicals Limited & 5 MLD of treated Sewage to Manali Petro Chemicals for industrial uses.
  • 84 MLD treated wastewater routed to nearby Buckingham canal reducing environment pollution.
  • Silt generated from Inlet chamber is being used to raise the entire low lying area of the plant.

Conclusion

There are many time tested and successful case studies in India which testify to the viability of power neutral STPs. Kodungaiyur set a precedent in this novel concept. The plant stands as a role model plant for “Comprehensive Sewage Treatment” which focuses on resource recovery with the conviction that “Sewage is a resource with economic value, not a liability.

Nemmeli desalination plant: a reliable model for coastal India

Challenge – Sustaining a water starved city:

India is the second most populated country in the world. With one of the highest rates of urbanization, we are no stranger to the water crisis. It sustains 18 percent of the world’s population but on the contrary has access to only 4 percent of the total usable water sources of the Earth.

Due to the lack of alternatives the country is majorly dependent on the surface water sources. But these are unevenly distributed across its states. Such conditions give rise to certain geo-political water disputes which further aggravate the water crisis and threaten the per capita availability of water.

The city of Chennai in Southern India was also facing similar issues. It has been historically dependent on surface water sources to sustain its drinking water needs. Since the city receives irregular rainfall, the replenishment of such water bodies was highly uncertain. At times when these reservoirs were running at a fraction of their capacities the residents had to resort to the use of ground water which had a negative impact on the water table of the city, thus causing sea water ingression.

The situation put enormous pressure on the government think tank and advisory committees to come up with a solution that would not only curb the prevalent water crisis but ensure water sustainability for future generations as well.

The solution:

Chennai being a coastal city is blessed with an abundant coastline, hence the city sought an answer to the water crisis in the form of large scale sea water desalination. There were certain challenges in the form of high power requirement to run such desalination plants and to build a plant which can treat sea water with varying salinity.

The situation called for technology experts who were commercially competitive as well, thus entrusting VA Tech WABAG with the responsibility.

Embodiment of the solution – The 110 MLD Nemilli Desalination Plant

In order to tackle the growing water stress, a 100 MLD (Million Litres per day) desalination Plant was envisaged along the coast of the Chennai City at Nemmeli

VA Tech WABAG was given the responsibility to design, build and operate this mega project, first of its kind for India.

The plant is equipped with the most advanced technology in the field of desalination. The entire process starts with the inflow of sea water through gravity flow in a 1 Kilometre pipeline embedded at the sea floor at a depth of 10 metres. The inlet water from the sea is pre treated with a state of the art pre treatment technology – Lamella Clarifier. The Lamella Clarirfier not only efficiently removes high amount of suspended solids in the incoming water but its compact size also reduces the footprint of the entire facility. The process water then flows through the disc filters to the Ultra-Filtration units.

Post the Ultra-Filtration, the water is treated by a single pass SWRO system which enables the removal of dissolved solids. A significant reduction in the salinity from around 35000 ppm to less than 500 ppm is achieved in this stage, which is the process core of the project.

The plant ensures production of the highest quality of desalinated water coupled with a process that optimizes power consumption. This is enabled by the use of high end pressure exchanging mechanism which uses the residual pressure of the reject from the RO membranes, thus boosting the pressure of sea water feed to the RO system.

The plant ensures production of the highest quality of desalinated water coupled with a process that optimizes power consumption. This is enabled by the use of high end pressure exchanging mechanism which uses the residual pressure of the reject from the RO membranes, thus boosting the pressure of sea water feed to the RO system.

The treatment cycle is complete with the remineralization of the process water with Carbon Dioxide and Lime in order to make the desalinated water fit for human consumption.

This project is a testament to the feasibility of desalination as an alternative coupled with WABAG’s process know how to optimize the lifecycle cost at INR 35 for every thousand litres of desalinated water produced.

In 2016 the plant’s capacity was further enhanced by 10 MLD with an innovative process retrofit and optimization by VA Tech WABAG’s water professionals. This was a welcome step for a city which was experiencing a dry spell that year.

Awards and accolades:

The Nemmeli plant today supplies water to over a million south Chennaites, thus projecting an alternative, sustainable and viable technological solution for water security which has been a challenge for decades.

Being the largest desalination plant in India to be executed on Design Build Operate basis, recognitions for this project have been global in stature. Success of this project reinforced the recognition given by Global Water Intelligence ranking WABAG among the top 10 desalination companies globally.

The plant was awarded with the Dun and Bradstreet Infra Awards in 2016. Another feather in WABAG’s cap was the International Engineers Institution’s Industry Excellence Award in 2016 that complimented the technology employed to make the project feasible and sustainable.

Present Status and the future of Desalination:

The Nemmeli desalination plant has satisfactorily helped bridge the water demand- supply gap (desalination caters to 25% of daily water supply in Chennai).This proves that advanced technology can provide solutions to one of humanity’s most critical problems – the scarcity of drinkable water.

Seeing this the Government of India has also acknowledged the sustainability promised by desalination especially along the coastal cities of India.

The recent announcements of two new desalination plants – a 150 MLD Plant and 400 MLD plant at Chennai are a few welcome measures promoting desalination as a reliable source to safeguard our country’s water security.

Solution for seamless performance of Soft Starters in WTP / WWTP

Introduction

Water being scarce resource, its treatment, storage and distribution to public uninterruptedly is a challenge to most operators. Large WTP/WWTP use high capacity pumps for transfer of treated water. In most plants pumps are driven by electrical drive which draws huge current during start up. Reducing starting current and stress on conductor and drive poses challenge to most electrical engineers. Thanks to technology that helped to address this challenge and today most high capacity pumps are equipped with soft starters. Here is a simple case study on elimination of its failure.

Challenges

Soft starters minimize the starting current and ensure smooth ramp up by switching IGBT/ SCR thereby mechanical stress on motor and driven equipment is drastically reduced. 50MGD WTP in Dwaraka Delhi treats raw water and supplies potable water to nearby residents. Treated water pumps are driven by 110Kw,415V motors. Installed soft starters are Danfoss MCD500 internal bypass type(fig.1) thus motor starts with soft starter and once full speed is achieved load is seamlessly changed over to bypass contactor and motor runs on DOL (Direct on line) mode. Soft starters were frequently failing and warranting frequent repair and replacement of control and power cards. On an average INR 6lacs PA was spent to keep treated water pumps running on account of this alone. This has inflated OPEX and jolted complete economics.

Principle Cause

Detailed RCA (Root Cause Analysis) was done and concluded that soft starter internal components were failing due to temperature. While drive running surface Temp. of soft starter was measured with IR temp. gun and found high (Table 1). Therefore it is very evident that PCB and components would be certainly higher than OEM recommended temperature which is 50 deg.c. Temperature rise is due to heat dissipation from internal bypass contactor which is continuously ON while drive is running soon after soft starter goes to bypass mode. There was no quick means of removing this heat due to compact design. As a result, power card and control cards started heating and components started malfunctioning finally leading to soft starter failure.

Resolution

Now the challenge is to isolate heat sensitive components from heat dissipating components. Hence internal bypass soft starter has been retrofitted with external bypass soft starter which has its bypass contactor outside the soft starter (fig 1). Previous version was replaced with Schneider ATS48C25Q soft starter. Post modification significant reduction in temperature of about 16 deg C was evident (Table 1).

Figure 1. GA of soft starter with internal and external bypass

Conclusion

100% uptime of equipment in water treatment is critical for known reasons. This makes us constantly thrive for higher MTBF (Mean time between failure). Higher MTBF not only reduces OPEX but also improves brand in such sensitive public related business. Retrofitting of internal bypass soft starter with external bypass irrespective of rating at right time and consideration of this scheme initially in capital projects makes sense in such competitive industry. ROI is just less than a year!

Sustainable solutions. For a better life.

The WABAG Group head quartered in Chennai with its global presence in 4 Continents and more than 20 countries has a work-force of more than 2,000. With a history dating back more than ninety years, the group has emerged as a leading pure play water technology player across the globe with focus on emerging markets.

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