Key Questions to Ask When Ordering nanofiltration system

What are the differences of different types of membranes?  Are all membranes of the same type (e.g. TFC) from different manufacturers the same? (example: an oil filter by Toyota is different from that of Mitsubishi).

You can find more information on our web, so please take a look.

You are right. These are very similar in construction and performance. Like other products, the main difference is in the reputation and reliability of the manufacturer.  However, because there are different manufacturers, membranes do come in several end type configurations depending on the manufacturer.  When ordering vessels, you will need to specify what brand of membrane you plan on using so the appropriate end adapters can be built in.  When replacing membranes with a different brand, you should check with the salesperson to make sure the end configuration is compatible for direct replacement.  If not, you can usually purchase an end adapter for a reasonably low price.

I am using RO Water for our La Marzocco espresso machine. Is it possible that the water may be too pure to allow the electric steam generator level controller to operate successfully?

Pure water will not conduct electricity.  For this reason if your steam generator level controller operates by measuring electrical currents, the water may be too pure to allow it to operate successfully.  We recommend using a Nanofiltration Element instead of RO, which will remove only 80% of the Ions, compared to 99% by RO.

I have been using Full Fit Elements in my system.  I just changed the elements and am now using BW which is a non-full fit element with a fiber glass cover. What kind of problems should I expect with the performance of the equipment?

There should be no problems.  These membranes are completely compatible.

I wonder if it would be possible to separate air with your membranes? I’m looking for a way to separate oxygen from air. What I understand, if concentrations and flow rates are moderate, a membrane-system is the best system to do that with.

Our membranes will not work for air.  They are good for liquids only.

1.Can we use the nanofiltration system for reduce COD (in treated water from leachate treatment plant) from 300 mg/l to 100 mg/l? 2. Does nanofiltration need the sand filter and activated carbon for pretreatment? 3. What is the good characteristic of feed water for nanofiltration?

Nanofiltration performance on waste waters is difficult to predict. Only sure way is to run a pilot test with one membrane.

I have seen RO systems with CTA and TFC membranes. The TFC units are higher in price. Are they necessarily better that the CTA? I want a small unit under the counter, about 10 GPD

The CTA membranes are chlorine tolerant whereas TFC membranes are not. The two systems should be very similar for your use.

What is the difference with Tap Water Membranes and Brackish water Membranes?

For more information, please visit ShekeSaisi.

There is no difference in the membrane material. Brackish water membranes have an outer shell of fiberglass whereas Tap water have a tape wrap. The construction allows Brackish water membranes to be operated at higher pressures required to treat brackish water.

I would like to get information about how to calculate the microfiltration membranes area knowing the characteristics of the water and the feed flow.

Unfortunately, it is not that simple. You will need to do a pilot test to determine the design criteria for each feed water source

Are Nano Filtration membranes suitable for removal of Flouride?

Let’s say you’re an application engineer in the textile industry, and you’re tasked with finding the right technology to separate dye from wastewater. There are specific questions you need to ask to guide you into making the best choice possible.

Question 1:  How fine is your application?

Membrane selection starts by first narrowing down the filtration categories you could work with including pressure-driven, osmotically-driven, and temperature-driven.

1. Pressure-driven filtration categories are further subdivided into four: microfiltration, ultrafiltration, nanofiltration, and reverse osmosis.
2. The osmotically-driven membrane separation process is also known as forward osmosis.
3. And another separation technique is partial vapor pressure difference induced by a temperature difference or temperature-driven filtration.

Question 2:  What are your membrane selection criteria?

Once you’ve narrowed down your filtration category, it’s important to evaluate selection criteria based on your application, and determine which is most vital to the success of your work.  

1. Chemical compatibility with the feed solution. You want to be confident that the membrane material you choose is compatible with your solution and doesn’t change characteristics over time. 
2. Membrane pore size. Pore size dictates how the selection or suppression process works. Larger pore sizes allow larger particles to pass, while smaller pore sizes are more selective about what passes through.
3. Membrane flux. It is also essential to find out which will produce the most flux or the permeate rate per unit area of membrane. The flux is a function of applied pressure, water temperature, and in the case of NF, RO, and some UF, the osmotic pressure of the solution under treatment. Other factors to consider when choosing your membrane material and characteristics are: temperature limits,  pH limits, affinity for water (hydrophilic or hydrophobic), and membrane surface charges.

Question 3: What membranes are ideal for a particular application?

Many manufacturers have optimized particular membranes for specific applications. If you’re still unsure of which membrane to use after establishing your selection criteria, you can also review the typical applications for a membrane. From our original example, if you are separating dye from dying wastewater effluent, our application engineers recommend either polyamide-TFN composite and F membranes or ultrafiltration membranes with very low pore size. Nanofiltration membranes are recommended if the dye is very water-soluble (and thus, small particle sizes). If you want the fastest path to your solution, give us a call, and one of our application engineers will get you there. 

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