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FlexKarb-C 10-100

Cutting-edge filtration system for diverse water flows

Customized to accommodate a wide array of flow rates, the FlexKarb-C excels in reducing pressure drops and maximizing media bed efficiency. Ideal for handling small to medium water flows for many applications, it has been designed to achieve low pressure drops even at high loadings and flow rates.

WaterMaid FlexKarb systems are all based on our standard modular-built solution that enables a huge flexibility, high operational reliability, and fast delivery time appreciated by all our customers.

High-performance industrial filtration systems

The Water Maid FlexKarb-C systems are turn-key systems possessing pressure filter vessels available with various types of active media. They can be used in all types of industrial and municipal water applications. The range of units offered under our Water Maid range of media filtration systems can accommodate any flow range, which makes them suitable for numerous industries and applications, such as treating industrial effluent from food and beverage plants, textile facilities, breweries, off-shore platforms and more.

The Water Maid FlexKarb-C, both standard and tailored adsorption water filtration systems, is optimized for small and medium scale water applications with flow rates between up to 100 m3/h per unit or more, up to 7 bars pressure. They are most effective as a polishing step for adsorption of micropollutants, pharmaceutical residues, colors, taste, dechlorination and other unwanted pollutants from the process water. The areas of application are wide, including COD and BOD removal, swimming pools, bottling plants or municipal or industrial wastewater treatment plants.

FlexKarb-C system is a pressure filter vessel for particle filtration, available with various types of active media

Technical data WaterMaid FlexKarb-C systems

Type Flow rate¹ nominal (m³/h) Design pressure (bar) Weight² in operation app. (kg) Full technical specs
10 10 6.2 3,050 Datasheet
12 12 7.0 3,700 Datasheet
14 14 6.8 4,350 Datasheet
17 17 6.0 5,250 Datasheet
20 20 5.2




25 25 4.3




30 30 4.0




35 35 3.5




40 40 5.5




50 50 4.5




60 60 4.0




75 70 3.4




100 100 4.0





¹Nominal filtration velocity: 15 m/h for dechlorination. Depending on application, the flow rate can be higher or lower.

²Total filter weight with pipe system, filling [1.5 kg/litre] and water. All weights are approximate and depending of design, pressure and type of filling.

How does it work?

The operational principles lie in pressurized, vertical fluid flows through the active media that adsorbs the contaminant load. Active media rests on at least two supporting layers of media, typically gravel and sand, which stabilize flows, distribute the flow velocity evenly across the active media bed, and maintain laminar conditions. This is especially important for adsorption beds as opposed to gravel or sand multimedia units, such as our Water Maid FlexKarb-S range.

Flow velocities are normally adapted to the current customer requirements and water quality, which determine the configuration of the treatment design and the sizing of each unit. The FlexKarb-C range is optimal for PFAS, PFOS and other types of recalcitrant environmental hazards today.

Installed Flexkarb tanks

Automation and backwashing

Normally, the need for backwashing in FlexKarb-C systems is limited. We recommend that our WaterMaid FlexKarb-S prefiltration systems be applied for separating suspended solids or other particles prior to implementing our FlexKarb-C units. However, due to operational conditions, manual or automatic backwashing may be essential in order to secure long-term operational stability.

Backwashing is applied by reversing the vertical flow-through during limited periods of time in order to limit pressure drops over time and remedy potential accumulation of solids which may prevent performance by blocking active media sites. Backwash liquid can be a separate water source or treated effluent liquid. For automatic backwashing, Mellifiq supplies time-based or pressure based backwash control units PLCs, please read more at the WaterMaid accessories section.

Illustrating the process of backwashing, a process to secure long-term operational stability

Treating Micropollutants at Malungs-Sälen's Municipality

Example case study of how our WaterMaid FlexKarb-C played an important role in treating micropollutants at a wastewater treatment plant. Our FlexKarb-C system was completely integrated by Mellifiq with automation, valves, piping, pressure gauges and sampling to optimize the removal rates of more than 100,000 ug/L micropollutants.

Filter media flexibility

Choosing the most fitting active media type is a vital aspect of any Water Maid FlexKarb that Mellifiq designs and delivers to our customers. This is evaluated meticulously by our design engineers for each specific project; the aim is to provide the best possible adsorption rates in order to minimize active media saturation and contaminant break-through.

Through our wide range of active media, any specific media characteristics is available with low ash content, high iodine numbers and particle size distribution for both granular activated carbon (GAC) and pulverized activated carbon (PAC) applications. In some applications, special surface impregnation may enhance the performance of the filtration system.

Biological systems (BAC)

Our Water Maid FlexKarb-C systems are also suitable for Biological Activated Carbon systems, in which active media beds with tailored granule sizes are used as carriers for biological treatment with attached growth. These systems are delivered with

active oxygenation systems to accomodate proper bacteria growth rate, and sometimes with low concentrations of dissolved ozone to increase substrate availability.

Integration with multiple technologies

FlexKarb-C systems are often part of a complete process and used specifically for polishing certain remaining pollutants after upstream separation, or as a protective chemical barrier. Mellifiq frequently designs and delivers water treatment processes consisting of multiple elements for disinfection, micropollutants, particle separation and dissolved organics. Here, our Water Maid range of systems plays an important role.

Please visit our other website sections to find out how tackle a broad variety of customer problems using our Saniray, Ozonetech or Nodora brand systems and products.

Related reference project.

Advanced water treatment eliminates micropollutants and allows for water reuse

Advanced water treatment for the pharmaceutical residues at a ski resort plant

Unique micropollutant solution at wastewater treatment plant

Eckes-Granini successfully reduces BOD and COD with advanced oxidation and adsorption

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