Comprehensive Guide to MBR Membrane Technology: Structural Principles & Practical Applications
Keywords: MBR membrane technology,Membrane Bioreactor working principle,MBR membrane cleaning methods,Hollow fiber MBR membranes,Industrial wastewater MBR systems,PVDF vs PES membrane comparison,MBR membrane li
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: 乾元环境 Date: May-10-2025 Visits: 14
1. MBR Technology Overview
The Membrane Bioreactor (MBR) represents a revolutionary advancement in 21st-century wastewater treatment, integrating biological processing with membrane filtration to achieve effluent quality surpassing conventional activated sludge methods. According to IWA statistics, global MBR adoption in municipal wastewater treatment has grown from 8% (2010) to 34% (2023), driven by four key innovations:
✔ Dual-Barrier Filtration: 0.1μm pores eliminate suspended solids/microorganisms
✔ MLSS Revolution: 8,000-12,000 mg/L sludge concentration (vs. 3,000-5,000 mg/L traditional)
✔ Premium Effluent Quality: Turbidity <0.2 NTU, COD <30 mg/L (direct reuse compliant)
✔ Space Efficiency: 50%+ footprint reduction
2. MBR Membrane Classification System
2.1 By Filtration Precision
| Type | Pore Size | Target Contaminants | TMP Range |
|---|
| Microfiltration | 0.1-0.4μm | Bacteria, SS, Colloids | 0.05-0.2 MPa |
| Ultrafiltration | 0.01-0.1μm | Viruses, Macromolecules | 0.1-0.3 MPa |
2.2 By Configuration
Flat Sheet Modules
Construction: Polypropylene support + PVDF membrane
Advantages: Fouling resistance, offline cleaning capability
Case: Kubota modules in 100,000 m³/day municipal project (Japan)
Hollow Fiber Membranes
Dimensions: 1-3mm OD/0.5-1mm ID
Configuration: Curtain/Bundle arrangement
Example: MEMSTAR SMM-1520
Tubular Membranes
Specifications: Ø5-15mm × 1-3m length
Application: High-strength organic wastewater (e.g., landfill leachate)
2.3 By Material Composition
| Material | Characteristics | pH Range | Service Life |
|---|
| PVDF | Oxidation-resistant | 2-11 | 5-8 years |
| PES | High flux/cost-effective | 3-10 | 3-5 years |
| PTFE | Heat-resistant (120°C) | 1-14 | 8-10 years |
3. MBR Membrane Structural Analysis
SEM imaging reveals four-layer architecture in PVDF hollow fiber membranes:
Support Layer (200μm): Polyester non-woven (Tensile >100 MPa)
Transition Layer (50μm): Macroporous structure (80-85% porosity)
Separation Layer (20μm): Finger-like pore structure (0.1μm pores)
Surface Layer (0.5μm): Hydrophilic coating (PEG grafted)
Key Parameters:
textCopy CodePorosity: 60-85%
Tensile Strength: ≥5 MPa
Pure Water Flux: ≥500 L/(m²·h·bar)
4. Determinants of MBR Membrane Lifespan
4.1 Influent Quality Management
COD Load: <8,000 mg/L (requires equalization tank)
Oil Content: <30 mg/L (needs DAF pretreatment)
SS Concentration: <100 mg/L
4.2 Operational Parameters
Aeration Intensity: 0.8-1.2 m³/(m²·h)
Suction Cycle: 8min ON/2min OFF or 7min ON/1min OFF
MLSS Maintenance: 8,000-12,000 mg/L
4.3 Fouling Control
5. MBR Operation & Maintenance Protocol
5.1 Daily Operation
Pre-start Checklist: >90% aeration uniformity
TMP Monitoring: Alarm at >0.25 MPa
Online Cleaning:
Standard: Backwash every 2hr (0.15 MPa, 30s)
Advanced: LongClear™ membranes (no backwash required, extended offline cleaning cycles)
5.2 Professional Cleaning Methods
| Fouling Type | Chemicals | Concentration | Duration |
|---|
| Organic | NaOH + NaClO | 0.1% + 200ppm | 4-6 hours |
| Inorganic Scale | Citric Acid | 2% | 2-3 hours |
| Biofilm | Peracetic Acid | 0.2% | 1-2 hours |
6. MBR Technology Applications
6.1 Municipal WWTPs
6.2 Industrial Applications
6.3 Emerging Uses
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