How Biofilter Media Are Produced in MBBR Media Factory?

Walk into any wastewater treatment plant and you'll notice thousands of small plastic carriers quietly flowing in the aeration tank. They don't make noise, but take on the biological treatment work that purifies water.
These simple-looking plastic rings are MBBR biofilter carriers. In this article, we take you inside the MBBR media factory and explore how high-quality MBBR biofilter media are produced from start to finish.

In the market, the most commonly used materials of MBBR media include:

• Expanded Polystyrene (EPS)
• Recycled Plastic
• Polyethylene (PE)
• Polyvinyl Chloride (PVC)
• Polypropylene (PP)
• High-Density Polyethylene (HDPE)

• Expanded Polystyrene (EPS): Very lightweight for fast aeration and mixing, with lower mechanical strength and chemical resistance than HDPE and PP.

• Recycled Plastic: It combines various polyethylenes or polypropylenes. The media is brittle and prone to cracking after repeated impacts inside aeration tanks.

• Polyethylene (PE): PE is also used for MBBR biofilter media with high biofilm compatibility. It can withstand various chemical compounds commonly found in wastewater without significant degradation.

• Polyvinyl Chloride (PVC): It's cost-effective and chemically resistant, but not to UV light.

• Polypropylene (PP): With a higher melting point, it is more often used for high-temp applications. Some special PP media can be designed for biological nutrient removal (BNR) processes.

• High-Density Polyethylene (HDPE): The most popular option of premium MBBR media manufacturers like AquaSust. We insist on 100% Virgin HDPE, with a density of 0.96g/cm³, which features:
▫️ Long-chain structure for water impact
▫️ Chemical resistance
▫️ Very low water absorption
▫️ Up to a 20-year lifespan

After selecting and preparing the raw materials, we use a screening machine to remove impurities, sort the plastic pellets and additives, and automatically blend them according to the required formulation.

Next is the injection molding stage, where the MBBR media take their final form. In the AquaSust MBBR media factory, multiple high-speed, fully automated injection machines run alongside traction units. Each machine is equipped with independent temperature control, pressure regulation modules, and robotic arms for automatic part handling.

So, what does the process involve?
• Melting: HDPE particles are heated to a fully molten, flowable state.
• Injection: Then it's injected into molds (K-type, C-type, or multi-channel tubes) with controlled wall thickness, hole size, and internal support structures.
• Cooling: The mold remains closed while the plastic cools and solidifies.
• Demolding: The molded media are removed from the molds.
• Cutting (if required): Use an automatic slicer to cut long, tubular media into individual segments.
• Preliminary inspection: Each batch is checked for size and appearance here.

The molded filter media cannot be shipped directly from the factory. They would go through several finishing steps, such as:

 

Surface Treatment

Cleaning

Hot-Air Drying

Surface Treatment: To promote rapid biofilm attachment, manufacturers adjust the surface roughness and micro-porosity of the media according to the model. The micro-textures can provide additional points for microorganisms to settle.

Cleaning: The media are thoroughly cleaned to remove any residual oils, dust, or impurities that could affect biofilm growth.

Hot-Air Drying: Next, the MBBR media are fully dried using a hot-air circulation system, ensuring stable performance during density testing, packaging, and transportation.

After production is complete, the MBBR filter media undergoes a series of rigorous quality inspections, such as:

Some manufacturers, including AquaSust, complement these standard tests with long-term cycling trials to observe performance under real wastewater conditions. This combination of continuous monitoring, lab testing, and real-use simulation ensures every batch can withstand operational demands.

Qualified media are then securely packed to prevent damage during transport. We package and mark them with production date, batch number, specification number, etc., using laser marking or coding equipment. Before shipment, each batch receives a final quality check to make sure everything is defect-free. Then, the products are stored in the warehouse and dispatched as soon as the booked trucks or containers arrive.

Now that you know how MBBR media are produced, you may wonder: "Can I customize the media for my project?" Absolutely! AquaSust provides several customization solutions, including:

● Density (0.92–1.05 g/cm³, etc): Tailored for aerobic, anaerobic, anoxic, or high-load tanks.

● Specific Surface Area: For municipal upgrades, industrial retrofits, or high-efficiency bioreactors.

● Structural: K-type, C-type, H-type, multi-channel, 3D structured carriers, etc.

● Material Formulation Upgrades: Anti-oxidation additives, stronger chemical resistance, special-grade HDPE.

● OEM Packaging & Private Mold Development: From CAD → simulation → sample molding → biofilm testing → mass production,

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Why Choose AquaSust

Well-experienced

Backed by 20+ years of experience and collaborations with top Chinese universities, we offer end-to-end support, from MBBR media enquiry to after-sales technical guidance.

Stable Production

AquaSust owns a 21,760 m² factory with over 150 production lines, with ample inventory of ready-made products, even for fast bulk and urgent orders.

Quality Commitment

Our factory is certified to ISO 9001:2015 and also complies with CE and RoHS standards, ensuring stable quality and safety across every batch of MBBR media.

Proven in Real Projects

Our MBBR carriers are applied in WWTPs, RAS systems, municipal, industrial, and food-processing wastewater projects, remaining reliable in different operating conditions.

With 2,000+ completed projects, AquaSust continues to support global partners with stable and reliable wastewater treatment solutions.