Improving a desalination plant by using Merus, here a RO System
In a lot of parts in the world, water is very difficult to come by. The water even out of bore wells, has to be treated before it is possible to use as drinking water. Especially bore well water in dessert area or where the ground water is heavily used the TDS content of the water can be very high. In a lot of cases reverse osmosis is used to reduce the TDS out of the bore well water and get a somehow acceptable drinking water. A Saudi Arabian company runs several RO Systems to produce drinking water.
Technically a high concentration of TDS gives a row of problems at the membranes of the RO, especially at systems running with high pressure. The solids solved in the water are only partly washed out together with the brine, a good portion of the solids, are blocking the pre filters and the channels in the RO membrane, and are causing the so called fouling. In this case after installation of a new set of membranes, the pressure at the inlet of the RO increased day by day, and the production capacity decline in the same ratio. So the experience from the customer has been they have to replace the sediment filter once a week and each and every membrane in all their RO systems, in less than 3 month.
In order to extend the time of replacement of a membrane it is common to add a cocktail of chemicals, to slow down the fouling. Stopping the fouling totally can hardly be achieved by using chemicals. Merus has been installed at this RO System, where the membranes have been already partly blocked. It could be seen immediately, the daily decline of the production of water stopped after the installation of Merus, it even increased to some extend over time. Recognizing stable results over some weeks, customer stopped totally adding chemicals to the system. Having stable results for more than a year, where no fouling of membrane happened and no replacement has to be done, the customer decided to add to all his RO Systems Merus Rings. Another positive side effect, as mentioned in the certificate, the amount of bacteria in the produced water got less and are now very stable far below 100 CFU/mL. The return of investment ROI in this case has been less than 2 month. Not only there are no chemicals needed anymore, the production is stable on the same high level, there is no shut down of production for replacement of some parts of the RO, and of course the lifetime of the membrane itself is far higher. As well the need of electricity in the pumps is reduced, due to the fact there is no fouling of the RO Membrane anymore there is less pressure needed to press the water through them.
See as well the certificate issued by the customer for more details.