How to select a membrane separator? Can you provide a suitable supplier?

Why is no one paying attention to me? When I searched on Baidu, there were very few membrane separation manufacturers. The principle of the membrane separator I need is to separate substances based on differences in molecular weight.

Do you need gas separation or liquid separation? I work in liquid membrane separation.

Liquid separation refers to the separation of polymer salts from inorganic salts such as sodium sulfate

The principle should be screening; it’s possible to design a separator for liquids by oneself. The key factor is the type of membrane material used in the core component, and separation can also be achieved through vaporization

I now have a general understanding that we need nanofiltration equipment to achieve separation. But I don’t know how to choose the specification

What exactly are the polymer salts you’re referring to? What is the difference in molecular weight compared to sodium sulfate? If the difference isn’t 100 times, it will be difficult to work with them

Sodium pentathiosulfate, molecular weight: 4000~8000. This post was last edited by Lai Lai on 2009-4-1 at 14:35.]

It is possible to consider trying using GE’s GM or PW membrane tests, but the effectiveness cannot be determined

I work in the field of membranes, specifically homogeneous ion exchange membranes. Used for the separation of acids and salts; not sure if it can help you. My email address is *anmiaozhang@163.com

Are there membranes with 1000 MWCO? It seems this is rare in China, right?

Membranes with a molecular weight of 1000 are mainly imported. There are many in our lab. If ultrafiltration with a molecular weight of 1000 is not available, nanofiltration with a molecular weight of 600–800 can be considered. However, for a molecular weight of 4000–8000, a 2500 UF membrane can be considered. Reduce the content of inorganic salts such as sodium sulfate while concentrating the polymer. Based on experience, the inorganic salts can be reduced to below 0.5% (mass percentage).

The cut-off molecular weight of GM is 8000, while that of PW is 10000, resulting in a relatively low retention rate. Of course, it also depends on the spatial structure of the polymer in question.

We will specify a membrane with 1000 WM; 1000 WM represents the characterization capability of the membrane. So, before making the selection, the membranes were actually determined in advance. Is it just the specifications of the equipment that are missing?

I think GM also has a 1000WM membrane, right?

In reality, achieving separation on an industrial scale cannot be based solely on the molecular weight of the materials. The poster mentioned a range of 4000–8000; in that case, ultrafiltration should suffice, and nanofiltration would be even better. However, if the spatial structure of the polymers changes, things won’t go as planned! I have worked on too many engineering projects – this kind of thing keeps happening!

Wow, the question posed by the original poster is really insightful. There are various types and materials of membrane separators; it is necessary to select the appropriate one based on the intended application for treatment. Additionally, the molecular weight of the substance to be processed as well as the desired outcome must be taken into consideration before making a choice. If the original poster wants to figure it out on their own, they can read books and materials related to membrane separation. If they are seeking help, it’s best to clearly explain the physical properties of the material to be processed as well as the goals to be achieved, so that other users can offer suggestions

If you need 1000WM, I can provide it. However, membranes with a capacity of 800–1000 WM have a higher retention rate for sodium sulfate, so you need to consider this carefully.

Will sodium sulfate retain a high level? So how can we achieve the goal of separation?

Membranes with a capacity of 600–1000 WMCO vary among different manufacturers, and it cannot be said outright that one has a high retention rate for sodium sulfate. How high exactly does \"high\" refer to here? 20%? 50%? Or 80%? For a given model of membrane, the retention rate for sodium sulfate is as follows: 1. The impact of sodium sulfate concentration in the feed water – at low concentrations (less than 0.5%), the retention rate is usually much higher than at high concentrations (greater than 5%). 2. Effect of inlet pH: At high pH levels (greater than 7.0), the retention rate is usually much higher than at low pH levels (less than 1.0). 3. Other influencing factors such as the types and concentrations of other components in the solution ； Temperature ； Operating pressure ； Light fluid flow rate, etc. This post was last edited by kuyeliu on 2009-4-5 21:58]

Since I am not aware of the details of your physical components and the specific separation requirements, it is difficult to give a general answer. The retention rate of sodium sulfate by the 1000WM membrane is close to 80%, resulting in a very long process for removing sodium sulfate. I have two types of nanofiltration systems available: NF030 (which retains 80% of sodium sulfate) and NF010 (which retains 30–40% of sodium sulfate). There is also an ultrafiltration system available (with a molecular weight cutoff of 4000) for you to choose from. Whether it is feasible specifically still needs to be tested.