Reverse Osmosis in Foodservice: Uses, Pros and Cons
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Update time : 2025-08-16 15:25:02
Reverse osmosis (RO) finds specific applications in foodservice scenarios, primarily determined by the total dissolved solids (TDS) content in water. It is worth considering when the TDS level is high enough to cause issues such as imparting an objectionable taste, leading to scale buildup in equipment, or resulting in poor quality of beverages and ice (e.g., weak carbonation or soft ice). The U.S. Environmental Protection Agency (U.S. EPA) has set a secondary standard of 500 mg/l TDS for drinking water, which serves as a recommended guideline for contaminants that may have cosmetic or aesthetic effects. Different foodservice applications have varying TDS requirements. For steam applications, water with very low TDS is necessary to prevent heavy scale accumulation that could damage or even destroy the equipment. In contrast, fountain beverage applications can tolerate TDS levels up to 500 ppm because scale is not typically a problem here, as no energy is applied to the water. Some Everpure RO systems come with a "blend" feature, allowing raw water to bypass the RO membrane. Both the raw water and the RO-treated water are filtered through a traditional taste and odor filter before being blended. This enables control over the TDS quantity, ensuring the system meets specific water specifications. For instance, a coffee recipe might require water with a TDS of 150 ppm.
When it comes to the benefits of reverse osmosis, it is highly effective at eliminating or significantly reducing a wide range of contaminants, outperforming most other types of water treatment. By removing 95%-99% of total dissolved solids, it is often the top choice for obtaining clean water free of TDS and other contaminants. Moreover, by stripping water of damaging contaminants that can harm equipment, it helps lower operating costs. RO systems are effective in removing excess salt, other dissolved minerals, taste and odor-causing substances, heavy metals, microorganisms, nitrates, and pesticides. Water treated by reverse osmosis has a noticeably cleaner and sparkling appearance, allowing the subtle flavors in foods and water-based beverages to shine through.
However, reverse osmosis also has its drawbacks. Despite their effectiveness, RO membranes are prone to loss of function due to several factors. The amount of contaminants, the size and type of equipment, and system pressure can all contribute to material buildup on the membrane. Additionally, disinfectant chlorine can attack some membranes. To address this, RO systems usually include a carbon prefilter to reduce chlorine and protect the membrane. A sediment prefilter is also used to prevent fine suspended particles in the source water from permanently clogging the membrane. Larger commercial systems sometimes soften the incoming water or add scale inhibitors to maintain membrane porosity.
Furthermore, RO systems are more expensive than traditional filtration systems and require more maintenance. They also have a waste factor, as a portion of the water supply must be used to flush contaminants down the drain, which can account for a significant portion of total water usage. Another drawback is that RO produces clean water at a slow rate, so a holding tank is necessary to ensure water availability during peak usage periods.
