- Home
- Companies
- Solecta, Inc.
- Products
- Solecta - Model Reverse Osmosis (RO) - ...
Solecta - Model Reverse Osmosis (RO) -Polymeric Membrane Solution
Reverse Osmosis (RO) products are one of the most commonly used membranes in both water treatment and process applications – particularly given the product’s ability to extract any remaining valuable components from a process, as well as to create a high-quality permeate. RO is widely used after ultrafiltration (UF) or nanofiltration (NF) as an efficient means of concentrating permeate from those processes while producing its own permeate stream that may either be utilized for further processing or reuse.
- Productivity
- Yield
- Quality
- Operating Efficiencies
- Peace of Mind
Reverse Osmosis refers to a classification of membranes where separation range is categorized by rejection characteristics of a known solute, traditionally sodium chloride (NaCl). Typical ranges of rejection are 96-99.8%. Like NF, separation with RO is largely based on diffusion of dissolved species through the membrane and overcoming osmotic pressure of the process fluid. The membrane configuration is usually cross-flow. For numerous process applications, polymeric RO membranes are produced via application of a thin film (e.g. polyamide) to a polysulfone (PS) UF substrate.
Examples of solids that will not pass through the membrane into permeate include proteins, virus, bacteria, and suspended solids greater than 0. 1-1 nm, or with a molecular weight cut-off (“MWCO”) of <10 Da. Any remaining high value materials left in a process stream would typically be concentrated by RO, making this format attractive as a final filtration step.Variables to monitor performance
There are several variables which are used to monitor RO system performance. These include the following operational parameters:
- Feed flow, pressure, and conductivity
- Permeate flow, pressure, and conductivity
- Retentate flow, pressure, and conductivity
- Temperature
- Other – parameters such as protein concentration and COD are utilized in process applications to measure performance. However, since these tests typically require offline measurement and/or more advanced analytical procedures, conductivity is oftentimes used as a proxy.
Calculations can also be performed to understand rejection and passage. Simplified formulas are provided below:
- Rejection % = (Feed Water Conductivity/Process Variable – Permeate Conductivity/Process Variable) / (Feed Water Conductivity/Process Variable)
Note that conductivity is an effective way to get a quick read on RO performance, but ultimately, measuring the specific rejection of the process variable (e.g. protein) is the best way to measure true process performance.
- Passage % = 1- Rejection %
Passage is simply the inverse of rejection. Maintaining high rejection and low passage is the ultimate goal of RO system performance. When this rises, it typically means there is some process issue that requires addressing via CIP, mechanical inspections, or potentially replacement.
- Recovery % = (Permeate Flow Rate / Feed Flow Rate) * 100
While recovery is a typical calculation used to measure water treatment performance (e.g, polishing) , it is also valuable in process applications to understand how much process stream is being recovered on a % basis. It is also helpful in understanding how well the system is concentrating the process stream.
- Concentration Factor % = 1 / (1 – Recovery %)
Since concentration is typically the main goal of RO in process applications, this is a good way to validate the effectiveness of your application. As is the case with other variables, changes in performance over time should be monitored to ensure optimal system performance.
When properly designed and operated, RO can offer several benefits over traditional separation process:
Compact footprint
With advances in element construction and system design, substantial surface area can be designed into a membrane solution vs traditional filtration technologies.
Lower energy consumption
These systems consume far less energy than thermally driven processes.
Ease of operation
RO membrane operations are well understood, and control systems can ensure smooth, safe separation operations.
Minimal negative effect on quality
RO would be able to remove materials without the risk of thermal degradation like evaporative processes.
RO is used broadly across process industries, most namely dairy, food ingredients, biotechnology/life sciences, beverages, and automotive manufacturing operations. Some of the key applications across these industries include the following:
- UF permeate processing (lactose concentration)
- Milk production (concentration)
- WPC and WPI production (solids concentration)
- Polishing (purification of COW water and other process streams)
- Sugar/sweetener processing (concentration)
- Other fermentation processes (concentration, water recovery)
- Polishing (condensate purification)
- Cell mass removal (downstream processing of bulk fermentation)
- Juice production (concentration)
- Final rinse (purification)
- Utility water (purification)