ch2mbr

Membrane Configurations from the MBR

MBRs are generally grouped into three technology configurations:

·  flat sheet (FS)
·  hollow fibre (HF) and
·  multi-tube or multichannel (MT/MC).

Each of the configurations has tended to be better suited for particular applications,
so the choice of configuration is important when considering selecting MBR technology for a particular use.

In general terms, it appears that flat sheet membranes are used almost exclusively
for immersed MBRs for both industrial and municipal applications, where they are sometimes
favoured for smaller installations on the basis of their operational simplicity.

Hollow fiber membranes are used almost exclusively for immersed MBRs, both for industrial and municipal applications,
where they are often favoured for larger installations on the basis of their lower membrane aeration energy demand.

The pumped multitube systems are often favoured for treating small effluent flows from industrial
installations on the basis of their robustness and operational flexibility and control.

The air-lift multi-tube system competes with FS and HF immersed systems.

Table 1: Membrane Selection (Plate or Hollow Fiber)

	Flat Plate	Hollow Fiber
Footprint	very good	better
Pore size	0.08 micron	0.1 micron
Material	PVDF	PVDF
Screening	1/8 inch	1/32 inch
TMP	1.03~2.9 psi	1.0~5.5 psi
O&M	relatively simple	complex
Air Requirement	high	high-medium
Membrane Cleaning	infrequent (6 to 18 months)	regular (backpulse/ chemicals daily)
Traditional Suitability	small flows, <br1 million gpd	12-20
Cleaning	in place, semi-annual, 4hrs, hypochlorite followed by citric acid	in place, hypochlorite 90days, semi-annual citric acid
Relaxation	membranes relaxed every few minutes	relaxation every 12 minutes for 60 sec.