How Does MBR Membrane Work to Achieve Water Treatment?

MBR (Membrane Bioreactor) is a novel water treatment technology that integrates ‌biological degradation‌ (via activated sludge) with ‌membrane separation‌ to achieve efficient solid-liquid separation, replacing traditional sedimentation tanks. Its filtration principles can be understood from the following aspects.

MBR membranes come in two main types:

● Flat Membranes‌: Plate-shaped, suitable for small-scale applications.

● Hollow Fiber Membranes‌: Hollow, fibrous structures with large specific surface areas per unit volume, widely used in household water purifiers.

The separation process relies on the ‌micro-porous structure‌ of the membrane:

● Water molecules and small solutes pass through the membrane's pores, while larger particles (e.g., activated sludge, suspended solids) are retained.

● The pore size of MBR membranes is typically around ‌0.1 μm‌ (some can be smaller), enabling effective removal of microorganisms and suspended impurities.

MBR operates in two primary modes:

● Hydraulic Head Pressure (HHP)‌: Utilizes the pressure difference between the feed water and permeate sides to drive filtration.

● Pump Suction‌: Uses a pump to draw water through the membrane, suitable for low-pressure systems.

During operation, aeration is often employed:

Aeration causes the membrane fibers to vibrate, preventing fouling (deposition of sludge on the membrane surface) and ensuring stable filtration.

MBR combines biological degradation (in the reactor) with membrane separation:

In the biological reactor, microorganisms break down organic pollutants. The membrane then filters out the microorganisms and suspended solids, producing high-quality effluent.

In summary, MBR leverages the micro-porous membrane's ability to separate by size, integrates biological treatment with physical separation, and uses aeration to maintain membrane performance, ultimately achieving efficient wastewater purification.