Brabant Water has begun a pilot programme to manufacture ferric chloride at its industrial water treatment facility in Zevenbergen, the Netherlands, using electrochemical technology developed with Delft-based company CIWI. The installation is intended to reduce dependence on externally supplied treatment chemicals while demonstrating whether a coagulant can be produced reliably at the point of use.
The equipment is housed inside a shipping container at the existing water treatment works. It uses steel and salt as its main raw materials, combining electrochemical processes to produce a ferric coagulant for removing dissolved organic matter from surface water used in industrial water production.
Initial operation will be limited to one of four treatment lines at Zevenbergen. Brabant Water and CIWI have worked on developing the process for more than a year, with the pilot intended to establish its performance under practical operating conditions before a decision is made about wider deployment.
The utility describes the project as the first use of on-site chemical production of this kind by a Dutch water company. Although Brabant Water also supplies drinking water, the immediate application concerns the manufacture of industrial process water rather than the introduction of a new chemical production method across its drinking water network.
Ferric chloride is used as a coagulant in water treatment. Iron ions interact with substances that would otherwise remain dispersed or dissolved, encouraging the formation of larger aggregates that can be removed through subsequent separation operations.
The effectiveness of coagulation depends on the characteristics of the incoming water and the chemical conditions established during treatment. The required dose can change with organic content, pH and the presence of other substances that interact with the coagulant.
At Zevenbergen, the pilot is intended to produce ferric iron, Fe³⁺, for the removal of dissolved organic material. CIWI has previously developed related technology using ferrous iron, Fe²⁺, for phosphate removal in wastewater, but those applications involve different treatment objectives and operating chemistry.
The on-site production process begins with electrolysis involving steel. Electrical current drives reactions that transfer iron into solution, creating an iron-containing stream that can be used in the subsequent preparation of the treatment reagent.
Bipolar membrane technology provides another part of the process. These membranes enable electrochemical separation and the generation of acidic and alkaline streams from suitable salt solutions, with CIWI using common salt to produce the mildly acidic component required by its system.
Combining the iron-containing and acidic streams in controlled proportions produces the coagulant used in treatment. The chemical composition and concentration must remain sufficiently consistent for the dosing system to deliver the intended effect as incoming water conditions change.
Producing a reagent continuously at a treatment works creates requirements different from receiving a finished chemical solution in bulk. Equipment must maintain the necessary electrical conditions, manage its raw material supply and produce reagent at a rate compatible with the water being processed.
The pilot therefore needs to establish more than whether the electrochemical reactions take place. It must demonstrate that the resulting chemical performs consistently during actual treatment operations, with sufficient production capacity and control to meet the requirements of the selected line.
The coagulant will support a process that includes dissolved air flotation. During this form of separation, small gas bubbles attach to suspended material or flocs, helping lift them towards the water surface, where they can be collected and removed.
Flotation performance depends on the characteristics of the material entering the separation stage. Floc size and stability, bubble formation, hydraulic conditions and the concentration of substances in the water all influence how effectively contaminants can be separated.
Changes to the coagulant must consequently be assessed alongside the existing treatment process. The amount of reagent introduced, mixing conditions and time available for floc formation can all affect the quality of water delivered from the line.
CIWI has identified dissolved organic carbon removal and water quality monitoring among the objectives of its Zevenbergen work. Previous laboratory tests using related treatment chemistry provide supporting evidence, but they do not establish the performance of the newly installed containerised system under routine operating conditions.
Control of reagent quality also influences how the equipment would be maintained. Electrochemical components, electrical connections, feedstock arrangements and membrane systems require inspection and servicing, while the treatment operator must retain appropriate control over dosing and the finished water quality.
The containerised design allows the initial production equipment to be installed on an existing site without constructing a dedicated chemical manufacturing building. Connections are still required for electricity, process interfaces, feedstock handling and the movement of reagent into the treatment system.
Modularity provides a potential route to increasing output. If the initial pilot demonstrates acceptable treatment performance, Brabant Water could extend the system to further treatment lines or use a similar arrangement at other facilities.
Such expansion would require an assessment of reagent demand, electrical requirements and the integration of additional production equipment. The ability to add modules does not establish that a larger installation has already been commissioned or that treatment performance would be identical at another site.
The project also changes the logistics of chemical supply. Conventional treatment reagents may be delivered as liquid solutions containing substantial quantities of water, requiring transport and storage of the finished chemicals before they are dosed into the process.
CIWI’s arrangement instead allows steel and salt to be stored locally and converted into reagent when required. Brabant Water says the raw materials are widely available and can be retained in quantities sufficient for several months of production, reducing its exposure to interruptions in deliveries of finished chemicals.
That approach does not eliminate the need for external supplies. The installation will continue to require electricity, raw materials, equipment maintenance and replacement components. Its resilience benefit depends on the availability of those inputs and the reliability of the chemical production equipment.
The utility also expects reduced transport requirements and less exposure to fluctuations in chemical prices. These remain anticipated benefits, with no measured full-scale savings in cost, energy consumption or transport emissions published for the Zevenbergen pilot.
Patrick van der Wens, project director at Brabant Water, has linked the programme to greater control over the supply of chemicals used in its operations. CIWI founder Jasper Schakel has emphasised the importance of developing the technology in cooperation with an industrial user so that equipment design reflects actual treatment requirements.
The first operating results will determine whether the reagent can meet the site’s treatment requirements across changing water conditions. No timetable has been announced for extending the system across all four lines, and the companies have not published an investment value or full-scale production capacity.
Zevenbergen will provide evidence of whether locally manufactured ferric chloride can replace part of the site’s conventional chemical supply without reducing treatment performance. The next decision will depend on consistent water quality, equipment reliability and the overall operating requirements of producing the reagent on-site.
