Opening Time:  Mon‑Sat  08:00 AM

Types of RO Membranes used in Commercial RO Plants

Types of RO Membranes used in Commercial RO Plants

Are you looking for the answer about types of RO membranes. Then this article is for you, but before we start first we have to know the history of Membrane.

Membranes for reverse osmosis

Moritz Traube created the first synthetic membrane known to exist in 1867. His most effective membrane, which he employed to research osmosis, was a precipitated layer of copper ferrocyanide. Later on, asymmetric cellulose acetate membranes with a comparatively high flux and effective salt rejection were demonstrated by Loeb and Sourirajan in 1963. When Gulf General Atomics and Aerojet General used the cellulose acetate (CA) membranes in spiral wound modules to filter water, RO membranes made their commercial debut.

Types of RO Membranes

Let us go through the different types of RO Membranes:

  • Cellulose Acetate Membranes (CA)

The asymmetric cellulose acetate membranes have NaCl rejection percentages of around 99.5%. The degree of acetylation in commercial CA membranes is roughly 2.7. This mixture offers a nice compromise between permeate flux and salt rejection. Combining CA with CTA reduces permeability while boosting mechanical stability and resistance to hydrolysis.

CA membranes provide a number of advantages:

1: They have superior mechanical qualities and are comparatively simple to build.

2: They also withstand chlorine damage reasonably well.

3: These membranes have a far higher tolerance to free chlorine, which can reach 5 ppm.

  • Cellulose Triacetate Membranes (CTA)

A little amount of chlorine in the water source is needed to prevent germs from growing on CTA (Cellulose Triacetate) membranes, which are paper by-product membranes attached to synthetic layers.

  • Thin Film Composite Membranes (TFC)

Chlorine must be eliminated from the water before it enters the TFC (Thin Film Composite) membrane, which is comprised of a synthetic substance. These membranes are more durable and can be employed at a higher temperature (45°C). The majority of TFC membranes are constructed from a porous, highly permeable support, like polysulfone, that is covered with a thin layer of cross-linked aromatic polyamide. The membrane’s ability to reject salt is provided by the coating.

TFC membranes provide a number of advantages:

1: They provide high rejection and high flux.

2: They can reject some low molecular weight organics.

3: They are more stable than CA over a wider pH range and at greater temperatures.

Characteristics of RO Membranes

The general characteristics of reverse osmosis membranes are described below:

S.No.Limitations of various parametersCellulose acetate (CA) membranesCellulose triacetate (CTA) membranesThin film composite (TFC) membranes
1.pH2 – 84 – 92 – 11
2.Temperature5°C – 30°C5°C – 35°C5°C – 45°C
3.Resistance to bacterial attackPoorFair/goodExcellent
4.Resistance to damageby chlorineFair (0 – 1 ppm)Good (0 – 3 ppm)Poor (0 – 0.1 ppm)
5.Typical rejection ofsalts at 60 psi85% – 92%92% – 96%94% – 98%
6.Typical rejection of nitrate at 60 psi30% – 50%40% – 60%70% – 90%
7.Typical treated waterproduction at 60 psi40 liter/m2 ofmembrane/day40 liter/m2 ofmembrane/day80 liter/m2 ofmembrane/day
8.Turbidity allowed infeed waterNilNilNil
9.Iron        allowed  in  feed water1 ppm1 ppm0.1 ppm
10.Relative costLowMediumHigh

Fouling of RO Membranes

It is a significant issue that the membranes experience. Generally, Fouling reduces flux and can happen on the surface of a membrane or inside its pores. Scaling, organics, colloidals and bio-fouling are the four main categories of fouling.

1: A biofilm forms on the membrane’s surface as a result of bio-fouling, which is caused by microbial contamination of feed water and raises the membrane’s barrier to water permeability.

2: Salts precipitate and settle on the membrane surface, which causes scaling.

3: Organic fouling is caused by chemicals like hydrocarbons that cover the surface of the porous support layer or clog its pores.

4: Particles like clay or silica that build up on the membrane’s surface are the main causes of colloidal fouling.

Conclusion

By including disinfectants, anti-scaling chemicals and other pre-treatment procedures, fouling can be somewhat managed. However, these are not fixes for the issue. It is still a critical area that needs to be improved for RO membranes. 

Contact one of our experts to learn more about our range of Commercial RO Plants and Types of RO Membranes! Call us at +91-9650608473 or send an email to enquiry@netsolwater.com for further queries.

Comments

  1. Rebbeca

    Wow, superb blog structure! How lengthy have you ever been running a blog for?
    you make running a blog look easy. The entire look of your
    web site is great, let alone the content material! You can see similar here e-commerce

  2. Santiago

    Have you ever thought about including a little bit more than just your articles?
    I mean, what you say is important and everything. But just imagine if you added some great images or video
    clips to give your posts more, “pop”! Your content is excellent but with images and clips, this blog could undeniably be one of the most beneficial in its field.

    Awesome blog! I saw similar here: Sklep online

  3. Arron

    Hi there! I’m at work surfing around your blog from my new
    iphone 4! Just wanted to say I love reading through your blog and look forward to
    all your posts! Carry on the excellent work! I saw similar here:
    Sklep internetowy

  4. Clayton

    It’s a shame you don’t have a donate button! I’d certainly donate to this brilliant blog!
    I guess for now i’ll settle for book-marking and adding your RSS feed to my Google account.
    I look forward to new updates and will talk about this
    blog with my Facebook group. Chat soon! I saw similar
    here: Sklep

  5. Deana

    Hello! Do you know if they make any plugins to assist with Search Engine Optimization?
    I’m trying to get my blog to rank for some targeted keywords
    but I’m not seeing very good gains. If you know of any please share.

    Many thanks! You can read similar text here: Najlepszy sklep

  6. Nelly

    Hi! Do you know if they make any plugins to assist with SEO?
    I’m trying to get my blog to rank for some targeted keywords but I’m not seeing very good results.
    If you know of any please share. Cheers! You can read similar art here:
    E-commerce

  7. Jerold

    Hey! Do you know if they make any plugins to assist with Search
    Engine Optimization? I’m trying to get my blog to rank for some targeted
    keywords but I’m not seeing very good results. If you know of any please share.
    Thank you! You can read similar art here: Sklep internetowy

  8. Duane

    Good day! Do you know if they make any plugins to help
    with SEO? I’m trying to get my blog to rank for some targeted keywords but I’m not seeing very good results.
    If you know of any please share. Thank you! You can read similar blog
    here: E-commerce

  9. Kenny

    Good day! Do you know if they make any plugins to assist with
    Search Engine Optimization? I’m trying to get
    my website to rank for some targeted keywords but I’m
    not seeing very good gains. If you know of any please share.
    Cheers! I saw similar article here: List of Backlinks

  10. Abel

    Howdy just wanted to give you a brief heads up and let
    you know a few of the pictures aren’t loading properly. I’m not sure why but I think its a linking issue.
    I’ve tried it in two different browsers and both show the
    same outcome.

    Take a look at my web-site :: vpn coupon 2024

  11. Bennie

    Good day! This is my first comment here so I just
    wanted to give a quick shout out and say I really enjoy reading through your posts.

    Can you suggest any other blogs/websites/forums that cover the same
    topics? Thanks a ton!

    Stop by my site :: vpn coupon code 2024

Leave a Reply

×

Hello!

Click one of our representatives below to chat on WhatsApp or send us an email to contact@commercialroplant.com

× Chat With Us!!