Having been
involved with bringing new water treatment technologies to market, I know how
corporate pressure to get a return on development costs for shareholders and
investors, as well as the need to keep up with competitors, or even the urgency
to enter the market due to a regulatory window of opportunity can result in a
technology being brought to market before it is fully developed and all kinks
are worked out. That was likely the case in the early 90’s when Memtec Ltd.
(Memcor in US) and soon after Zenon started trailblazing the application of
MF/UF for drinking water filtration.
In the late 80’s before Memtec was bought by US Filter it was a small publically listed company in Australia with some innovative membrane technology but there was a lot of pressure to get wins to demonstrate the potential for the new technology and keep investors happy. Slow adoption in target food and wastewater markets led Memtec to focus on the higher potential drinking water market in the U.S. where tightening regulations was opening up new opportunities (ref). I believe Zenon’s early focus was also in the industrial wastewater market before drinking water opportunities beckoned.
Birth of North American MF/UF Market
Numerous sources indicate the first significant
sized MF system installed in North America was by Memcor at the 3.6-MGD
Saratoga WTP, CA in 1993 (Delphos, Wong). Up to that point there were three
MF/UF systems less than 1 MGD installed in the US between 1987 and 1992 (AWWA
Journal). After 1993 the growth in MF/UF installations started to grow
exponentially (Figure 1), I assume helped by the Milwaukee cryptosporidium
outbreak in 1993 and subsequent implementation of more stringent filtration
requirements by the EPA’s Long Term 1 Enhanced Surface Water Treatment Rule in
2002 (LT1ESWTR).
Figure 1: U.S. MF & UF Installations (AWWA) |
By the end of the 90’s, Memcor/US Filter and Zenon were the ‘Big Two’ in the MF/UF Market. In the late 90’s, Pall, who at that time had little or no experience municipally, entered the market with Asahi’s Microza PVDF pressurized MF membrane module. By then, submerged/vacuum membranes had become the preferred configuration, particularly for large systems, but by the mid-2000s fierce competition between US Filter and Zenon had resulted in product modifications to increase cost competitiveness. This may have been responsible for emerging issues with membrane fiber and module integrity. Some of the issues may also have been because the technology was being pushed into more challenging applications. The Asahi membrane fiber did not have the same integrity issues, possibly due to the manufacturing method as claimed by Pall (called the TIPS process), although I think the fact the Asahi fiber was twice as thick and Memcor and Zenon’s also was a major factor (Based on current experience with Dow membranes manufactured the same way as Memcor and Zenon but having same thickness as Asahi). Pall capitalized on the integrity problems experienced by US Filter and Zenon and quickly grew to be the market leader by the late 2000s, with pressurized modules now back in vogue.
Figure 2: Vacuum Membrane Systems from Zenon (R) and US Filter (L) |
Another
discovery was the use of Aluminum Chlorohydrate (ACH) as a coagulant for
organics removal and to reduce organic fouling in preference to Alum and Ferric
Salts. I may have had an indirect role in that discovery. In the mid-90s I was
working for a company in Australia that manufactured ACH and we converted a
direct filtration WTP near Geelong, Victoria (Barwon Water’s Wurdee Boluc WTP)
from Alum to ACH. After they found out that
ACH extended filter run times and reduced sludge volumes (more compact floc at
lower Al doses), Barwon Water’s Engineering Manager took a drum of ACH to the
Meredith WTP, where they had just started up a 2.5 ML/d Memtec MF plant, I
think one of the largest MF plants in Australia at the time. The feed water had
a high TOC level and with direct Alum dosing in the feed, they had to do a CIP
on a weekly basis due to rapid TMP buildup (give or take – I am going from
memory). When they changed to ACH, the CIP frequency was reduced to monthly,
reducing chemical use significantly and increasing plant uptime. Soon after,
Memtec started buying ACH from our company and rebadging it for their membrane
installations worldwide.
In recent years, new entrants to the market have had a free ride being able
to replicate aspects of Asahi’s membrane fiber and using process operating conditions
learned from the blood sweat and tears of the Big Three over the past 20 years.
So while I may get frustrated at the slow rate of adoption
of the new membrane modules on the market and acceptance of the OEMs who build
systems using these, the Big Three have certainly earned their Brand Equity for
all their hard work in bringing MF/UF filtration of drinking water to the mainstream
and creating the municipal MF/UF market that exists today.
Delphos, P; “Membrane Filtration Basics 101”, VA AWWA Plant
Operations Committee, Operations Conference, Virginia Beach, VA, May 2014
Wong, J; “California Leads the Way in Drinking Water Membrane
Filtration”, WaterWorld Vol 28, Issue 7, 2012.