What Is the Difference Between Media and Membrane Filtration?

Media and membrane filtration are common systems in liquid and gas filtration. Whether you want a solution for Storm Water management, drinking water systems, wastewater treatment, or gas filtration, it’s crucial to understand the two systems to make an informed decision.   

In this post, we elaborate on the two filtration systems, their uses, and how they work to guide you towards the best filtration method for your needs. We will start by uncovering the need to know information around media filtration.

What Is Media Filtration and How Does It Work?

Media filtration is a process that uses granular material to filter impurities. The granular material is often made of a bed of sand, crushed glass or granite, peat, woven fabrics, fiber, or metal screens, depending on the impurities being removed. Some media filtration systems allow you to switch the filters based on the intended filtration requirements. Examples of common media filters include fiberglass, cotton, ceramic materials, Nomex, nylon, polyester, and polypropylene. Filter Holdings offers a number of other media options to fit your needs.

Media filtration works in two ways. The first method involves passing the liquid through the filter, which traps the pollutants on the surface and allows the purified substance to pass through. The second way removes the impurities through chemical reaction and adsorption.

The process of adsorption is known as cation exchange and is often used to remove nutrients and metal from the material being purified.

Media Filtration Applications

Some applications of media filtration include:

• Drinking water filtration
• Storm Water management
• Oil and gas filtration
• Aquaculture and irrigation
• Pool and spa

What Is Membrane Filtration and How Does It Work?

How does membrane filtration compare to media filtration? Generally, media filtration is used to capture large particles or remove pollutants such as pathogens, chlorine, iron, and other metals and impurities through adsorption. 

On the other hand, membrane filtration uses a porous material that blocks the impurities and separates them from water as it passes through. Membrane filtration processes are suitable for separating particles (molecules) of different characteristics and sizes. Furthermore, membrane filtration does not use a chemical process to filter liquid.

Pore size and durability of the membrane material are two key factors to consider when planning an effective filtration. Pore size requirements are based on the type of impurities being captured.

Similarly, the membrane’s durability determines how it will withstand heavy use. For example, in a Storm Water application, the membrane should be durable enough to withstand the pressure of lots of water passing through it.

Membrane filtration is considered a more effective pretreatment process than conventional systems. Essentially, the process has two pollutant removal mechanisms. The primary removal involves blocking the particles as the water passes through, while the secondary mechanism removes impurities that are attached to the captured particles.

Membrane Filtration Categories

There are four categories of membrane filtration – reverse osmosis, nanofiltration, microfiltration, and ultrafiltration. Their main difference is the membrane pore size and the substances they are able to separate.

Reverse Osmosis

Reverse Osmosis is typically used in water purification. It works two ways, allowing the liquid to pass through while flushing impurities to the drain. It has the tightest membrane, only allowing water to pass through. In water treatment, reverse osmosis is used to process pure water since it removes all substances, including minerals.

Nanofiltration

Nanofiltration uses slightly open membranes, allowing water and other small ions (monovalent ions) to pass through while blocking larger particles, such as bacteria.

Ultrafiltration

Ultrafiltration uses membranes with larger pores, but the pressure applied is low. This allows liquid with monovalent and multivalent ions to pass though while bacteria, viruses, and suspended solids are blocked.

Microfiltration

The membranes are relatively larger, allowing most substances to pass through other than suspended solids and bacteria.

Membrane Filtration Applications

Typical applications of membrane filtration include:

• Drinking water treatment (pretreatment, desalination of salt water, surface water filtration, etc.)
• Biomass removal
• Wastewater treatment
• Gas filtration

Having established a background of the two processes, let’s now look at how the two differ from each other.

What Is the Difference Between Media and Membrane Filtration?

In review, though both media and membrane filtration are used to remove pollutants, their application is quite different. The main differences between the two include:

Technology

Media filtration uses a chemical process to filter the impurities. On the other hand, membrane filtration does not use chemicals to clean the water and gasses, making it a clean technology.

Effectiveness

Membrane filtration is more effective at removing impurities. For example, reverse osmosis can purify water by removing all substances from it. With media filtration, you might need to filter the water several times to remove most of the particulates.

Cost

Membrane filtration is more cost-effective than media filtration in terms of installation and operational costs. The former uses fewer processing steps while achieving higher purity than the latter. In addition, the energy requirements in membrane filtration are relatively lower than media filtration.

Durability

Filtration membranes have a much-limited lifespan due to fouling and clogging, while media filters have a much longer life expectancy, especially with consistent maintenance.

Conclusion

Getting the ideal filtration solution for your plant is key to guaranteeing process efficiency and cutting costs.

Generally, membrane filtration has more pros than media filtration. But when it comes to application – Storm Water management, oil and gas filtration, drinking water treatment, wastewater management, etc. – each solution has its advantages and disadvantages.

Depending on your objectives, you might require media filtration, reverse osmosis, nanofiltration, ultrafiltration, microfiltration, or a combination. Regardless of your decision, the most crucial thing is to note their differences in durability, labor requirements, degree of purification, and the overall overhead costs of running the systems.

At Filter Holdings, we have a wide range of filtration materials. Our fabric choices include polypropylene, polyester, PPS, Teflon and more. We guarantee system efficiency thanks to unique construction technology that ensures the products are cut to size and have sealed edges to eliminate seams. When it comes to setting up effective filters, we are committed to our clients’ success.

Contact us today and let us help you find the best filtration for your manufacturing process.