Salt free Nano filtration 1

[vij36]

Dear All,

I came across the below water softening methods in this website wqa.org.

Link
[ul]
[li]Chemical softening—lime softening, hot and cold; lime-soda softening[/li]
[li]Membrane separation softening—Nano filtration[/li]
[li]Cation exchange softening—inorganic, carbonaceous, or organic base exchangers[/li]
[/ul]

Are there practical systems implemented using Nano filtration.

Basically we need Salt free water softening methods and systems.

Thanks,

 

[ashtree]

Nanofiltration is a technique used for water softening but its success will depend a lot on what your feed water quality is and water your treated water quality objectives are. A number of water utilities in Florida use nanofiltration for water softening at a city supply scale.

Nanofiltration is very similar to reverse osmosis but in effect the membranes are not as tight and will typically only reject compounds that are divalent as well as particulates and organic matter. Thyis means that elements such as calcium and magnesium will be rejected very well but sodium will not be. Nanofiltration will however produce a waste stream in which the calcium and magnesium is concentrated. This stream is likely to be between 10 and 30% of the feed flow in volume.

If you are wanting very low amounts of hardness (lets say less than 10mg/l) you will probably need to go to reverse osmosis.

Both processes will need to have very high quality feedwater to be successful

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[vij36]

Thank you for your kind reply.

The requirement appears to be strange to whomever I have shared with.
It is basically water softener without sodium content in the output.
Whatever softener i have come across all are having sodium output.

Any inputs please ...

 

[vij36]

Just now I have come across this ...

Link

It says ".... it does not remove the grains from your water. A filter catches larger particles as the smaller calcium and magnesium particles pass through into the polyphosphate coating material."

Is this a tested system ?

 

[ashtree]

I am sure it has been "tested" by the inventor. I would recommend that you don't waste your money on such a device.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[Alex smith]

According to my experience. Electric water softener works better.

 

[Alex smith]

I was browsing and i came across this information.
Link
When your softener or filter do nano filtration, it removes best minerals from it.
Do you guys agree from it?

 

[itsmoked]

Nano filtration for water softening, another name for it is: "a scam water softener".

Keith Cress
kcress -

http://www.flaminsystems.com

 

[IRstuff]

There's certainly a bit of controversy, since most of the "anti" salt-free articles are written by actual water softener suppliers. That said, it sounds plausible that salt-free systems do not actually "soften" the water, since they really can't remove the dissolved minerals, and they actually attempt to crystallize the minerals so they can't deposit as scale on pipes and in water heaters. There may be sound reasons for avoiding softened water, like sodium content, etc.

https://www.uswatersystems.com/blog/the-hard-truth-about-salt-free-water-softeners

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[itsmoked]

If you really need non-salt (i wouldn't drink it) then follow the 'salt' softener with a simple RO system for any cooking/drinking needs.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Magher Aghasia]

You should take a closer look on the differences between reverse osmosis and nanofiltration so you can understand how each can help you in softening water. Both are highly advanced and efficient water treatment systems that share similarities in regards to their look and features. Nevertheless, Nanofiltration systems use the latest technology by incorporating certain features for further performance that reverse osmosis systems can not do.

 

[waterfilterupdates]

If you are living in the city area, Electrical water conditioners are better choice. Because its not salt-less water softeners so you will not feel the slippery feeling but still its depend to the type of the Descaler that which one are you going to use.

 

[vij36]

Thank you for all the kind inputs.

I gave up searching for nano filtration and want traditional resin based softeners.

Basically the plant is for an NGO and they wanted an economical setup.

I got two options given by a vendor:

Details:
TDS 750 ppm
Total Hardness as Caco3 considered for design: 500 ppm

Option 1: 12.5 cubic meter/ hr with OBR of 12.5*10 = 125 cubic meter
Option 2: 12.5 cubic meter/ hr with OBR of 12.5*20 = 250 Cubic meter

Treated water quality hardness <250 ppm after blending.

Request honorable members to give their valuable suggestions to tweak the system to design for an economical design since the NGO is for a charity cause and a good design may reduce their expenditure.

Thanks,

 

[Maryam Lylaa]

Dubai water filters is one of the best water purifier in Dubai.Purifiers are available at

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[bimr]

This is an old thread, but still open.

The decision to select a water softener or nanofiltration depends on a number of factors including raw water quality, flow rate, treatment plant skill set, and the desired finished water quality.

For the application of 12.5 cubic meter/ hr, the water softener may be the best option. A nanofilter will be much more expensive and require more operator attention.

In the US, the acceptable standard for TDS is 500 ppm (mg/L), a standard established by the USEPA under the authority of the Safe Drinking Water Act. This is a secondary standard, that is, it’s a standard that is based on aesthetics (taste) rather than health impacts. It is not enforced, and many public water systems deliver water that has a TDS concentration that is higher than 500 mg/L.

The WHO (World Health Organization) also considers the TDS standard as an aesthetic standard and has published the following guidance for TDS: excellent, less than 300 mg/L; good, between 300 and 600 mg/L; fair, between 600 and 900 mg/L; poor, between 900 and 1200 mg/L; and unacceptable, greater than 1200 mg/L.

Many people in the world drink water every day that has a TDS level higher than 1000 mg/L. The water doesn’t taste good, but the TDS by itself isn’t necessarily unhealthy. However, high TDS levels are frequently accompanied by concentrations of other substances that are harmful to health. The most common are usually the heavy metals (arsenic, chromium, cadmium, mercury, lead, and a few others).

Nanofiltration membranes have a nominal pore size of approximately 0.001 microns and an MWCO of 1,000 to 100,000 daltons. Pushing water through these smaller membrane pores requires a higher operation pressure than either MF or UF. Operating pressures are usually near 600 kPa (90psi) and can be as high as 1,000 kPa (150psi). These systems can remove virtually all cysts, bacteria, viruses, and humic materials.

Because NF membranes also remove alkalinity, the product water can be corrosive, and measures, such as blending raw water and product water or adding alkalinity, may be needed to reduce corrosivity. NF also removes hardness from water, which accounts for NF membranes sometimes being called “softening membranes.” Hard water treated by NF will need pretreatment to avoid precipitation of hardness ions on the membrane. However, more energy is required for NF than MF or UF.

Typically, NF membranes used for softening applications remove more than 95 percent of total hardness.

AWWA

AMTA Org

Finally, agree with the previous posters that "salt free" water softeners or electronic water treatment gadgets are scams.

 

[Michael Abebe]

Reverse osmosis is a separation technique by exerting pressure on water to move via a membrane and eliminate particulate matter and dissolved solids. Water is compelled to work its way from the concentrated side to the diluted side, as well as the filtration system retaining solutes.

Nanofiltration, which is often characterized as an alternative version of RO, utilizing lesser fine membranes than a reverse osmosis system. This can be seen as the necessary feed pressure becomes nearly half of what would be needed for a reverse osmosis system.

The size distribution of particles expelled by NF and RO are considerably overlapping. A nanofiltration system can generally disallow particles as comparatively tiny as 0.001 μm while ro systems can reject particles up to 0.0001 μm in size.