Giving the Big Three Some Love!

 

From some of my posts it may seem like I have something against the Big Three MF/UF system suppliers (Evoqua, GE and Pall). That actually is not the case, and I have a lot of respect for how these companies brought Microfiltration/ Ultrafiltration from a novel drinking water treatment process in the early 1990s to the mainstream technology it is today. Before you read on, I will give a disclaimer that my chronology and facts may not all be correct and I am going from memory via my experience in Australia in the 90’s and what I have been able to verify on the internet.
   

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)

Most of the initial MF systems installed in the 90’s were Memcor systems with Polypropylene (PP) hollow fiber pressurized modules that were not chlorine tolerant.  Sometime in the mid to late 90’s Zenon entered the market with their submerged vacuum driven PVDF membranes that were chlorine resistant. Perhaps due to fouling issues with the PP membrane and higher energy costs, Memcor quickly developed a PVDF submerged membrane to compete with Zenon. I was visiting Memcor’s Memfarm R&D site at Windsor outside Sydney in the late 90s when they were testing their new submerged PVDF MF system at the same time that my company was testing a MIEX ion exchange pilot as pretreatment to a Memcor MF pilot. Both technologies were first implemented on the full-scale in 1999 at South Australian Water Corp’s Mount Pleasant WTP, near Adelaide, SA.

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)

But I didn’t really want to dwell on the history of how the Big Three got into the drinking water MF/UF market, and intended to focus on some of their  process developments that are taken for granted today and are being taken advantage of by new entrants to the market.

 I already indicated the move to chlorine resistant PVDF membranes, and chlorine resistant membranes in general, which went a long way to reducing fouling rates of membranes by allowing cleaning with sodium hypochlorite. This also allowed Maintenance Cleans (MCs) or Chemically Enhanced Backwashes (CEBs) using chlorine or chlorine/caustic where a MC/CEB is conducted every 1-7 days to reduce irreversible fouling and CIP frequencies. I think this was first developed by Pall and is now common practice at all MF/UF installations.

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.

 There is no doubt that Memcor (now Evoqua) and Zenon (now GE) had to endure a lot of hard times in developing the North American MF/UF drinking water market, optimizing process operation while still learning the limitations of the technology. I am sure Pall also went through some learning pains as these companies developed the MF/UF technology into the robust and reliable process it is today (not to forget the engineers who also had to work out how to specify these systems…).  These companies probably lost a lot of money on projects in the early days. I know there have been other membrane companies also involved in developing the market over the past 20 years, but my focus here has been on the major players in terms of market share in North America.

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.