Tips for choosing an MBR technology supplier
Factors to consider
The choice of technologies is generally based on two sets of two options:
- membrane configuration: flat sheet (FS) vs hollow fibre (HF)
- process configuration: immersed (iMBR) vs sidestream (sMBR).
For large municipal plants (see Largest MBR plants), the HF configuration is usually favoured because of the slightly lower energy demand compared with the FS configuration. For relatively small flows of industrial effluent the sidestream configuration is sometimes favoured on the basis of its robustness, operational flexibility and smaller footprint.
Lastly, the range of services provided by suppliers can vary. Some suppliers provide on the membrane as a commodity, i.e. the membrane modules alone, whereas other provide the complete technology. The technology can comprise just the membrane and the ancillaries (the frame, skid and/or tank with the related pipework and infrastructure) or the complete treatment system, including upstream and downstream operations.
Amongst the different technology suppliers of membranes of the same configuration there are differences in technology attributes such as membrane material, membrane packing density (the membrane surface area to module volume ratio) and air scour rate, and module dimensions.
Across the world there are dozens of suppliers of individual, discrete MBR membrane module products − apparently around 75 in 2014 according to Industrial MBRs by Simon Judd. Some of the more established products have changed ownership since their original commercialisation in the 1990s, as well as in most cases changes in the membrane material and/or module design.
As well supplying the membrane module as a commodity product, there are companies focused on the provision of the complete MBR system. This is particularly the case for the smaller sidestream systems based on multi-tube (MT) membrane modules. Since MT membranes are standardised, provided most commonly as 200 mm-diameter modules, they can be interchanged as desired.
There are a number of OEM (original equipment manufacturer) sMBR suppliers globally, each offering different sMBR process configurations based on standardised MT membranes. These suppliers may be active regionally or else specialise in specific industrial sectors. All focus their activities largely on industrial effluent treatment, including reuse applications. In the case of the water recovery and reuse, the suppliers are usually able to provide both the sMBR and the downstream NF or RO plant for the complete system.