Challenge
A power plant on the northeastern coast of England was faced with a short-term difficulty with the supply of demineralized water from its regular supplier. In order to continue operating without the fear of being short of this precious resource and facing a shutdown, it needed a solution, and fast. Veolia was able to provide an emergency mobile water treatment solution to overcome the problem, once information on the water supply and the desired quality and quantity were analyzed. The customer required 24,000 gpm (90m3 /h) of demineralized water for their high-pressure boiler, at the quality of <1 µS/cm and <20 ppb SiO2. To add to the challenge of the project, the feed water supply was raw river water, which was known to fluctuate in quality depending on the time of year, and variation in weather.
Solution
The solution involved dosing the river water with acid, biocide and coagulant before being sent to a 13,000 g (50 m3 ) contact tank. From the tank the water was pumped on two MobileFlow* Filter trailers, and sent onto two MobileRO* (Reverse Osmosis) units loaded with cellulose acetate membranes, running at 90% rejection and 70% recovery. The water was then degassed in a Forced Draft Aerator (FDA) and finally re-pumped onto the customer through two MobileFlow Demineralizer (DI) trailers. When the ion exchange resin was exhausted the trailers would be replaced and sent to have their resin regenerated at the Veolia regeneration facility. Flow Rate: 24,000 gpm (90 m3 /h) Inlet Conductivity: 700 µS/cm Outlet Conductivity - MobileRO 65 µS/cm Outlet Conductivity – MobileFlow 0.056 µS/cm
Result
The customer benefited from having a complete working water treatment plant in within 4 days of requesting the system, with no burden on the customer’s operational staff. This gave the customer confidence there was sufficient water to continue power production.
The quality of the water produced by Veolia’s temporary water treatment plant (0.056 µS/cm; < 10 ppb SiO2) exceeded the expectation of the customer. The plant manager was very pleased with the rapid response to their emergency need and paid tribute to the mobile system and service by saying, “The operational phase has been exceptional, quality of the product exceeded expectations and staff have proven to be diligent and reliable.”
