Both Reverse Osmosis (RO) and Nanofiltration (Nano) are membrane processes that remove total dissolved solids (TDS) from your water, leaving it with substantially lower ionic content. Water with high TDS can wreak havoc on the brewery and your finished product. The availability of these membrane processes makes it possible to easily improve this potentially troubling feature of mineralized water supplies. The question is: Which process do you want or need for your brewery?
RO and Nano are essentially the same basic process. Water is forced through a thin membrane that has extremely small pores. The water passes through the pores, but much of the ions dissolved in that water cannot pass through those pores. The result is much purer water with relatively low ionic content (low TDS) on the other side of that membrane.
RO and Nano processes differ due to the relative size of the pores in their membranes. RO pore diameters are about 10 times smaller than those in Nano membranes. That results in RO systems producing water that has only a few percent of the original ionic content, while Nano systems produce water with over 10 percent of the original ionic content. Depending on the content of the raw water, that difference can make a real difference in the brewery.
Now, you are probably asking: “Why not take out as much ionic content as possible? I can always add minerals to the water!”
Yes, taking almost everything out and adding back only the ions you want is an option. But you may want to consider that this has a real cost to your brewery operations in the form of energy and water usage. In some settings, Nano produces as little as 15 percent waste from the incoming water volume while RO can waste 30 percent or more. Industrial RO and Nano systems require pumps to increase the water pressure flowing through the membranes. Since water flows more easily through the larger Nano pores, the pressure level and pumping cost for that process are lower. Another consideration is that most water usage in a brewery can tolerate or benefit from minor ionic content and it may not be necessary to take nearly all of the ionic content out.
While this suggests that Nanofiltration will save you money, its applicability is dependent upon your raw water quality and how pure you need the water in your brewery. There are cases where Nano will not produce acceptable water quality because the raw water is just too mineralized. So, it is necessary to understand the quality of your raw water supply and use that information to model the probable treated water quality from a Nano system before purchasing a system. The same modeling is also used to predict the treated water quality from a prospective RO system and let you know how pure that water is likely to be.
In addition, modeling helps establish the configuration and operating parameters that can give you better system performance and life. Bru’n Solutions performs membrane system modeling and can help you work with RO or Nano system suppliers to give you a membrane system that meets your needs. Having your own advocate that is dedicated to your brewery’s needs and goals can make your system purchase and operation, more secure.
Include Bru’n Solutions on your team when exploring this important water treatment decision.