How to Prevent MBBR Media Damage by Mixers?

Summary: In MBBR systems, protecting the biofilm carriers (media) is as important as the mixing itself. Learn how LJ Water Treatment Equipment customized a QJB 2.2 Submersible Mixer with a dual-guard system to solve media breakage for a client using 30mm Bio-Chips.

The Challenge: When Mixers Become "Media Grinders"

Moving Bed Biofilm Reactor (MBBR) technology relies on plastic carriers to support microbial growth. However, many plant operators face a common nightmare: standard submersible mixers often act like "grinders," shattering expensive media into pieces.

Broken media not only reduces biological treatment efficiency but also clogs downstream screens and damages mechanical seals. Recently, a client approached LJ Water Treatment Equipment with this exact concern for their MBBR tank.

The LJ Solution: Dual-Guard Customization

Instead of offering a "one-size-fits-all" product, our engineering team analyzed the client’s specific media type—30mm diameter "Bio-Chips" (potato chip type).

To ensure 100% protection, we customized our QJB 2.2 Submersible Mixer (304SS) with the following upgrades:

1. Front & Rear Protection Nets

Most standard "guarded" mixers only protect the front. However, hydraulic suction can pull media into the impeller from the back. We installed high-strength Stainless Steel 304 guards on both the front and rear of the impeller, creating a complete safety cage.

2. Strategic Mesh Sizing (10mm Grid)

While the client’s current media is Dia.30mm, we looked toward the future. We designed the guard with a 10mm x 10mm mesh.

● Future-Proofing: Even if the client switches to smaller carriers later, the mixer remains compatible.

● Hydraulic Balance: The 10mm grid is large enough to allow optimal water flow (maintaining mixing efficiency) but small enough to block any carrier from touching the blades.

3. All-304 Stainless Steel Construction

To prevent corrosion in the biological environment, the entire unit—including the customized guards and the mixer body—is made of premium 304 Stainless Steel.

The Result: Satisfied Clients and Sustainable Flow

The client was highly impressed with the precision of the customization. After installation, the MBBR tank achieved a uniform 0.3m/s flow without a single piece of media being damaged.

"Expertise is not just about selling a machine; it's about understanding the client's process," says the technical director at LJ Water Treatment Equipment.

Looking for a Customized Mixing Solution?

Established in 2001, LJ Water Treatment Equipment specializes in solving the toughest wastewater challenges. Whether you need a guarded for MBBR or a high-torque for industrial sludge, we are here to help.

Explore our specialized range:

● for sensitive biological flocs.

● for large-scale aeration tanks.

● for high-viscosity media.

Contact us today to find a suitable submersible mixer!