Innovative dual-mode Keppel desalination plant in Singapore begins commercial operations with large-scale and compact Nijhuis Industries DAF pre-treatment

Singapore’s fourth desalination plant, the Keppel Marina East Desalination Plant (KMEDP), has commenced commercial operation. Unique is its large-scale, dual mode for the treatment of both freshwater from the Marina Bay Reservoir, or seawater. For the pre-treatment of the seawater, contractor Nijhuis Industries has provided eight high rate dissolved air flotation units for removal of solids. With a total plant recovery rate of 98%, the Nijhuis DAF units provide a small environmental footprint utilizing Nijhuis plate pack technology.


The desalination plant can produce 137,000 m3 of fresh drinking water per day. It has been built by Keppel Infrastructure under a Design, Build, Own and Operate (DBOO) arrangement with the National Water Agency, the Public Utility Board of Singapore (PUB). Keppel will operate the plant for 25 years under this contract arrangement. All plant facilities are located underground, with a green parkland area above the facility at ground level.

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"The desalination plant can produce 137,000 m3 of fresh drinking water per day"

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Two water sources:

Depending on conditions such as high rainfall, the plant can choose to draw from either the Marina Bay or the sea in the production of desalinated water. When the Marina Bay reservoir reaches high levels during the heavy rain season the plant may elect to draw water from the Marina Bay, which then requires less energy and fewer steps in the treatment process compared to desalination.

The engineering design can draw water from the sea and the reservoir, collecting both into a dual flow chamber, through pre-treatment using flocculation and dissolved air flotation, then ultrafiltration; a two-pass reverse osmosis system; finally, post-treatment using ultraviolet disinfection. The pre-treatment consists of eight Nijhuis Dissolved Air Flotation Units followed by Ultrafiltration.

Help building a more resilient, sustainable, and inclusive future

Mr. Menno M. Holterman, CEO of Nijhuis Industries and Senior Executive Vice President of SAUR Industries, said: “After the announcement of the partnering with SAUR, the start of the operation of the Marina East Desalination plant is another unique moment in the 116-year history of Nijhuis Industries. We are extremely proud that our team together with Keppel, PUB and other technology providers have successfully realized an impressive climate-resilient desalination plant.

With a strong focus on footprint reduction, the lowest possible energy and chemical consumption and a total plant recovery rate of 98%, the plant perfectly fits into our unique ‘reduce-reuse-recover’ philosophy. The testing and commissioning during the Covid-19 pandemic brought about some inevitable challenges. A big compliment must be made to the commitment of the Nijhuis Industries team as one of the contractors to overcome these challenges and deliver a successful project with Keppel. This shows once again the fulfilment and dedication of water professionals, even during these challenging times, to help to build a more resilient, sustainable and inclusive future”.

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"With a strong focus on footprint reduction, the lowest possible energy and chemical consumption and a total plant recovery rate of 98%, the plant perfectly fits into our unique ‘reduce-reuse-recover’ philosophy"

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Small DAF unit footprint due to plate pack technology

The Nijhuis concrete High Rate i-DAF units have plate packs that make particles/flocks float to the surface with the injection of air. The floating solids are automatically and continuously being removed by a scraper mechanism. The plate packs designed by Nijhuis, increase the separation area, and ensures that even the smallest flocks are removed from the intake water.

In comparison to classic DAF units without plate packs for desalination plants, a DAF unit with plate packs reduces footprint requirements by 30 to 60 percent. Especially for the purification of sea and surface water above 800 m3/hr., pre-treatment solutions must be compact, robust, stable, and modular at the same time.

Innovative aeration system

The i-DAF system is based on the innovative i-AERATION system which forms fine air bubbles for the separation of particles ensured by the patented non-clogging depressurization nozzles. Micro air bubbles are dosed in and before the inlet construction of the DAF unit. In the i-AERATION system, a part of the treated water is brought under a pressure of 5 bar, making air dissolve in water. By reducing the pressure down to 1 bar, small air bubbles of 20 to 60 micron are formed, which quickly stick to the impurities in the water and cause a high degree of clarification.

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About Keppel Infrastructure

Keppel Infrastructure (KI) is a wholly owned subsidiary of Keppel Corporation Limited, a leading company listed on the Singapore Exchange. KI drives the Keppel Group's strategy to invest in, own and operate competitive energy and environmental infrastructure solutions and services.

Keppel Seghers, a wholly owned subsidiary of KI, is a leading provider of comprehensive environmental solutions, and provides consultancy, design and engineering, technology development and construction of large-scale environmental projects.

Keppel Infrastructure Services houses the technical support and Operations & Maintenance (O&M) capabilities within the Keppel Infrastructure group. It operates energy and environmental related infrastructure facilities globally.

About Nijhuis Industries

Nijhuis Industries delivers solid and adaptive solutions for sustainable water use, energy, and resource recovery. We help industries, utilities, and cities to reduce, reuse and recover to advance water and climate change adaption and help building a more resilient, sustainable, and inclusive future.

Nijhuis multidisciplinary teams develop, design, and implement smart and game changing solutions based on Nijhuis proprietary and innovative technologies. We help our clients to meet their increasingly demanding sustainability requirements, lower their environmental footprint, combine productivity and energy efficiency, and reduce life cycle cost at the same time.

With headquarters in the Netherlands, Nijhuis Industries is active in all geographical regions around the world, serving over 2,600 references from its Sales & Service Centers in the Netherlands, Germany, England, France, Spain, Dubai, KSA, Poland, Russia, Singapore, USA & Latin America.

For more information

Nijhuis Industries
Menno M. Holterman
Chief Executive Officer
Senior Executive Vice President Saur Industries
Tel: +31 314 749 012