The MBR Book: Principles and Applications of Membrane

4 The MBR Book
when legislation demands higher water quality outputs than those that can be
achieved by conventional technologies that organisations are led to consider the
merits of installing an MBR plant for their purposes.
It appears to be true that traditionally decision-makers have been reluctant to
invest the relatively high start-up costs required on a relatively new technology
(�15 years) which produces an output of higher quality than that required. This is
especially so when MBRs have historically been perceived as requiring a high degree
of skill and investment in terms of operation and maintenance (O&M) with key operating
expenditure parameters – namely membrane life – being unknown (Frost and
Sullivan, 2003). Whilst robust to changes in loading with respect to product water
quality, MBR O&M protocols are critically sensitive to such parameters because of
their impact on the membrane hydraulics (i.e. the relationship between throughput
and applied pressure). Whilst there are many examples of the successful application
of MBRs for a number of duties, there are also some instances where unscheduled
remedial measures have had to be instigated due to under-specification, inappropriate
O&M and other factors generally attributable to inexperience or lack of knowledge.
All of this has fed the perception that MBRs can be difficult to maintain.
In the past there have been an insufficient number of established reference sites to
convince decision-makers of the potential of MBRs and the fact that they can present
an attractively reliable and relatively cost effective option. This is less true today,
since there are a number of examples where MBRs have been successfully implemented
across a range of applications, including municipal and industrial duties
(Chapter 5). In many cases the technology has demonstrated sustained performance
over the course of several years with reliable product water quality which can, in
some cases, provide a clear cost benefit (Sections 5.4.2 and 5.4.4).
Lastly, developing new water technology – from the initial laboratory research
stage to full implementation – is costly and time consuming (ECRD, 2006). This
problem is particularly relevant considering that the great majority of water technology
providers in Europe are small- and medium-sized enterprises (SMEs) that do
not have the financial resources to sustain the extended periods from conception at
laboratory scale to significant market penetration.
1.4 Drivers for MBR technology implementation
Of the many factors influencing the MBR market (Fig. 1.3), those which are generally
acknowledged to be the main influences today comprise:
(a) new, more stringent legislation affecting both sewage treatment and industrial
effluent discharge;
(b) local water scarcity;
(c) the introduction of state incentives to encourage improvements in wastewater
technology and particularly recycling;
(d) decreasing investment costs;
(e) increasing confidence in and acceptance of MBR technology.