Membrane Bioreactor (MBR) technology has become the gold standard for wastewater treatment plants requiring high-quality effluent for reuse. This technical article provides the design parameters, operating cost breakdown, and procurement guidance that EPC engineers and project owners need.

MBR vs Conventional Activated Sludge (CAS)

Parameter	MBR	CAS + Clarifier
Effluent TSS	<1 mg/L	10-30 mg/L
Effluent BOD5	<5 mg/L	10-20 mg/L
Effluent Turbidity	<0.2 NTU	2-10 NTU
MLSS Concentration	8,000-15,000 mg/L	2,000-4,000 mg/L
SRT (Sludge Age)	15-30 days	5-15 days
Footprint	50-70% smaller	Baseline
Sludge Production	20-30% less	Baseline
Water Reuse Potential	Direct reuse	Requires tertiary treatment

Critical Design Parameters

Membrane Specifications

Parameter	Hollow Fiber	Flat Sheet
Membrane Material	PVDF	PVDF/PES
Pore Size	0.1 um	0.08-0.2 um
Flux Rate (Design)	12-25 LMH	15-30 LMH
Operating TMP	10-50 kPa	5-20 kPa
Module Area	20-40 m2/module	0.8-1.5 m2/panel
Cleaning Method	Backwash + CEB + CIP	Suction + CIP

Biological Design Parameters

• HRT (Hydraulic Retention Time): 4-8 hours
• SRT (Sludge Retention Time): 15-30 days
• F/M Ratio: 0.05-0.15 kg BOD/kg MLSS/day
• DO Concentration: 1.5-3.0 mg/L in aeration zone
• Anoxic Recycle Ratio: 200-400% (for nitrogen removal)

Operating Cost Breakdown

Annual operating costs for a 2,000 m3/day MBR plant:

Cost Item	Annual Cost (USD)	% of Total
Membrane Aeration Energy	$18,000	35%
Biology Aeration Energy	$12,000	23%
Chemical Cleaning	$5,000	10%
Membrane Replacement (7-yr life)	$8,500	16%
Polymer & Chemicals	$3,000	6%
Labor	$5,000	10%
Total Annual OPEX	$51,500	100%

Unit treatment cost: $0.07/m3 (or $0.07 per 1,000 liters)

MBR Retrofit Strategy: Double Capacity Without New Construction

For existing CAS plants facing capacity limits, retrofitting the clarifier with MBR modules can:

• Double treatment capacity within existing tank volume
• Eliminate clarifier solids carryover issues
• Produce reuse-quality effluent
• Reduce sludge production by 25%

Essential Upstream Protection

MBR membranes require fine screening (1-2mm) upstream. Hair and fibers cause irreversible membrane fouling. Feiran EP’s inward-flow perforated plate screens provide >95% capture rate at 1mm openings.

Feiran EP MBR Solutions

Feiran EP offers both hollow fiber and flat sheet MBR systems with Siemens PLC automation, complete with CEB/CIP cleaning systems. Available as standalone modules or integrated into containerized treatment plants.

Request MBR system design: sales@yixingenviroequipment.com | WeChat: 008613771308660