IDA 2022 World Congress a Global Meeting of Desal Minds

After changes of venue and multiple delays due to the Covid pandemic, the 2022 International Desalination Association (IDA) World Congress was finally held in Sydney Australia, October 9-13. It is the first time I have been to this conference, or any truly international water conference for that matter, and it was exciting and inspirational to see the global networking and established relationships across continents and the open sharing of technical knowledge and experiences. Everyone was drawn together by a common interest in water treatment, mostly by desalination, and protecting the earth’s most natural resource, no matter the country, language or culture. I may sound a bit cliché, but I was truly moved by the spirit and sense of common cause of the conference.

What’s New is the World of Desal? Brine Mining!

The main focus of the technical program was seawater desalination but there were some interesting topics and new developments being discussed in the desal world. Most notable to me was how to handle waste concentrate and a lot of interest in brine mining. Highly concentrated brine is being seen as a potential resource for rare earth metals, including lithium. First there needs to be processes to concentrate brine higher than conventional seawater membranes and companies such as Gradient and Toyobo presented on osmotically assisted RO (OARO) processes that can concentrate brine from a seawater process up to 130,000 mg/L TDS without needing significantly higher pressures. Osmotic assistance is provided by applying a saline stream on the permeate side, which lowers the osmotic pressure difference across the membrane, allowing permeate production at feed pressures less than the osmotic pressure of the feed. There is also interest in ultra-high pressure membranes and housings for achieving higher seawater recoveries and therefore higher brine concentrations, but I think if the counterflow processes are feasible, they are a safer and probably lower energy option.

 Once you have the highly concentrated brine, you have to extract the valuable constituents and from one presentation I saw from Dr. Monsalvo from Aqualia, that involves a lot of treatment steps… So it looks to me the recovered metals would need to be very valuable to offset the high cost of extraction. With world shortages in these elements, I’m sure with continued research the extraction costs will go down making these processes more feasible. There is no shortage of research in this area! There were also many presentations looking at minimizing the environmental impact of brines, indicating the industry realizes this needs to be addressed to ensure desalination is a viable water supply solution into the future.

Wastewater reuse also had a prominent share of the program, recognizing the role of desalination in reuse applications, with several dedicated sessions and two panel discussions, one of which I was very pleased to participate on.

The IDA Water Reuse Panel I was excited to be part of

I was also very impressed with how the technical sessions and panels were all conducted in the exhibit hall in walled-off areas, so it was easy to jump from session to session or to a panel discussion without leaving the hall. Meals were also served in the same area keeping attendees together all day. This is a great model for other conferences if it is logistically possible.

I can’t say I have anything negative to say about the show. Very professional production, great technical content, great networking, awesome venue! As long as you were able to get to Sydney… 

The comments and opinions in this post are my own and not those of my employer.

Manganese Removal Ain’t Manganese Removal!

 

I was looking at specifications for a project earlier this year that had very tight targets for iron and manganese (combined target of >0.06 mg/L) but there was no pilot data to back up that these targets were achievable. Bidders were required to guarantee these limits would be met by the specified pressure filter system with Greensand Plus media. When there was pushback in guaranteeing the performance of the system (that the engineer had designed) without any prior testing to show this was achievable, the response from the engineer was that there were other Greensand Plus filters in the State that were achieving these levels so there should be no issues making the performance guarantee…

This was essentially saying that the performance of a treatment process on one water source should be expected on a totally different source water without considering the water quality of the two sources. Anyone who knows anything about water treatment knows while iron is relatively easy to remove, manganese is a totally different animal. While manganese may be easy to remove on one water source, it could be very difficult to remove on another.

 In Chapter 3 of the AWWA ‘Iron and Manganese Removal Handbook, Second Edition’ the following statements are made:

• Oxidation of Fe and Mn: Manganese Dioxide (manganese in the oxidized form) forms a far finer floc (than ferric hydroxide), so fine at times that a granular media filter will not remove it.
• Organic Complexing of Fe and Mn: Operators experiencing difficulty in removing Fe and Mn (especially Mn) have uncovered some common factors:

o   A level of organic carbon (TOC) over 2 mg/L

o   Some level of ammonia or hydrogen sulfide in the feed water

• Adsorption Removal Methods (my summary): Manganese is best removed by adsorption on a manganese dioxide media like Greensand Plus or Pyrolusite. Iron is best removed by precipitation/filtration because iron adsorption blinds the media. Therefore, when both are present, the best process used is a combination of iron oxidation/filtration and manganese adsorption.

Further to the last point, oxidation of manganese takes a much longer time than iron where you are looking at from seconds to a minute for iron (Chapter 5, Chlorination) and up to up to 30 minutes or longer for manganese. Therefore in a filter system where an oxidant is dosed in the feed piping to the filters you can have adequate time in the piping and space in the filters above the media for iron oxidation (a few minutes) while allowing adsorption removal of the manganese.

There was also a very good article in AWWA’s Opflow in December 2021 titled “Evaluate and Optimize Manganese Treatment”. This article explains that the form and levels of manganese can vary considerably between wells. All manganese removal methods described in this article are based on sorption to the filter media. Therefore conditions must be optimized for the sorption mechanism on manganese oxide coated media including ensuring there is a free oxidant residual to provide a continuously regenerated adsorptive surface. The pH also impacts the Mn reaction kinetics with pHs above 7.0 more favorable.

As mentioned above, TOC, ammonia and H2S create a chlorine demand which impacts the chlorine available to oxidize the Fe and regenerate the filter media for Mn adsorption. Because the iron oxidation reaction is a lot faster compared to TOC, you typically get iron oxidation in the presence of TOC, as long as the iron is not organically bound to the TOC. When ammonia and H2S are present you may need a higher chlorine dose to overcome the demand from these compounds and provide sufficient iron oxidation. While you are not trying to remove manganese by oxidation/filtration, you still need a free oxidant residual to keep the manganese dioxide media regenerated so that is adsorbs the manganese. Therefore, a water with a high chlorine demand can impact the ability of the media to adsorb manganese. If ammonia is present, potassium permanganate may be a good option rather than chlorine as the oxidant because it does not react with the ammonia.

If iron and/or manganese is complexed with organics, the oxidation process can be significantly impacted. At a minimum, a higher oxidation dose and longer oxidation time will be required and if this works you could still create another problem with the formation of disinfection byproducts. Coagulation may be a better option to remove organically bound manganese and possibly iron also.

So clearly, iron and particularly manganese removal chemistry is not simple, and you can’t assume if the Fe and Mn levels on one water source are similar to another water source that a particular treatment technology will work equally on both. Other constituents in the water source impact removal performance and must be taken into consideration and ideally bench and/or pilot testing should be conducted to confirm the effectiveness of a proposed treatment process. To steal a saying from an old Mobile oil commercial, Manganese Removal Ain’t Manganese Removal!

The comments and opinions in this post are my own and not those of my employer.

Has Ceramic Membranes Missed its Window of Opportunity?

 

Some ceramic membrane advocates may not like what I am saying here, but I believe the window of opportunity in the U.S. for ceramic membranes is closed… Ten to fifteen years ago when many of the polymeric membranes on the market had significant integrity issues, there was a lot of interest in ceramic membranes offering warranties of 20 years or more and virtually no breakages over this period. At that time the leading manufacturer of ceramic membranes for large municipal systems was Metawater (know as NGK up to 2008) with a large installed base in Japan. Originally Metawater had an exclusive arrangement in the US to sell through Kruger and a contract for a 5 MGD system was secured with Parker CO around 2009. At this time, Memcor and Zenon, two of the largest membrane system suppliers at the time, had experienced a lot of membrane integrity issues at many installations helping to create a lot of interest in ceramic membranes. Despite this interest, high costs of ceramic membranes and the systems prevented adoption for drinking water applications at any other large-scale installations (see my 2011 post). Around 2015, when Metawater had started selling their ceramic system directly rather than through Kruger, a 7 MGD system was installed at Butte MT. I wonder if selling through Kruger was not the best strategy, where Kruger was not well known as a membrane system supplier and had a large suit of established water treatment technologies (such as Actiflo) that would have diluted the sales and marketing effort towards its ceramic membrane systems. I think the opportunity was missed to sell a lot more ceramic membrane systems 15 years ago.

Membrane Integrity Advantage over Polymeric has diminished the Past 10 years

At the time that Memcor and Zenon were having their membrane integrity issues, Pall with the Asahi membrane was quickly establishing a reputation of having a very robust membrane with minimal fiber breakages and was quickly gaining market share. Riding on the back of Pall’s success, around 2010, companies such as Toray and Dow (now Dupont) brought membranes to market that had similar fiber thicknesses, same material (PVDF) and were outside-in pressurized modules as were Asahi’s. As OEMs such as Wigen Water Technologies and H2O Innovation installed systems with these membranes it was found that these membranes did have significantly improved integrity compared to the earlier Memcor and Zenon submerged membranes. I do have to mention that as the early pioneers of large-scale MF and UF membranes, Memcor and Zenon were learning on the run about membrane materials, module construction and cleaning regimes. The later entrants to the market have capitalized on these developments to produce very good membrane modules the past ten years.

With much improved polymeric membranes available now, plus the ability to have Open Platform/Universal MF/UF racks, I do believe the opportunity for wide adoption of ceramic membranes for standard municipal applications has passed. I discussed this with some ceramic membrane veterans (ex Metawater, PWNT and Nanostone) at AWWA's ACE in San Antonio last month and they said there are still good opportunities in Europe for replacing some of the older, poor performing UF membranes (I assume these are inside-out PES membranes), none of which really gained traction in the U.S., with the exception of the Inge/Dupont multibore membrane which is a lot stronger than its predecessors. But I have to say it looks like ceramic membranes will remain to a niche product in the U.S. in the foreseeable future as I predicted in my post back in 2011.

The comments and opinions in this post are my own and not those of my employer.

Equipment Supply Contracts Should be Thrown Out and Started Again

 It is time for OEMs and Contractors to make a stand!

Ever since I have been involved in the capital supply business in North America, equipment procurement contracts in the water treatment industry have treated suppliers as banks for contractors and owners, with ridiculously long price validation periods, crippling liquidated damages for delays and uncapped liabilities. Well maybe the times are finally a-changin’!

In times of low inflation, stable government, no pandemics, reliable supply chains, no conflicts in regions with critical raw materials and a competitive contractor bidding market, perhaps the contracts of the past presented less risk to OEMs. How long ago has it been since we were in that situation??

Contracts that require the OEM to hold a bid price for 90 days before award and then when awarded, hold the price for 1-year before delivery (and I have seen up to 3 years) can’t be accepted anymore. That is being a bank for the contractor and owner where the OEM is financing the project, having to pay material suppliers well in advance of shipping the equipment (where delivery is often the major payment milestone) and absorb any price increases from the original quote from a vendor (which could be provided weeks before the bid) through submittal preparation and approval and notice to commence manufacturing which is often at least 6 months and longer for major process equipment. And that was a concern before the current supply chain issues! Not to mention preselection or direct bids as is often used for membrane systems, where following submittal approval the owner then goes to bid to contractors to install the equipment – the lead time from original quotes to actually getting the notice to commence manufacturing is often a year or longer. Engineers and owners are in for a rude awakening to OEM responses to contract terms for preselection or direct bids in the future…

Here are a few examples of how current market conditions have brought OEMs to the tipping point of outright rejection of traditional contract terms:

Following the concern with nickel supply because of the Ukrainian war, suppliers of stainless steel are only holding quoted prices for 24 hours. How can you bid a project with stainless vessels and piping without significant risk of margin erosion or even losing money? After the pandemonium in the nickel market a well-known manufacturer of stainless steel cartridge filter housings voided all quotes given before March 4. So what about the bids you used their pricing for prior to that date? Is that a case of Force Majeure?

Allen Bradley components, the predominantly specified controls for water treatment systems, already had stretched lead times from 8 weeks to 24 weeks earlier this year. Then there was a Corona Virus outbreak in Shenzen, China’s silicone valley, where some AB components are made – now AB is not committing to any delivery schedule… How then can you sign a contract with LDs when you don’t know when you can get a critical component required to operate the system? And what about contracts you signed in 2020/21 before there were these delays – that is certainly Force Majeure! I feel that controls components have become the toilet paper of the water industry with end users and equipment manufacturers hoarding them where they can, increasing leads times further...

Some may say that OEMs should just build in contingency to prices when it is known how long the price is to be held for. So when we bid a project in January where the price is to be held for 90 days before award, how do we know there is to be a war between Ukraine and Russia that starts in late February resulting in nickel prices skyrocketing in early March and stainless steel prices doubling in days? And that is only 40 days after the bid? And then ten vendors are listed on the bid, some you have never heard of, and you have to hope all ten will have same concerns as you and object to the same contract terms or put in the same contingency…

Some may say why not order materials as soon as submittals are approved to reduce the risk of price increases. This is the bank situation again. Then the OEM must pay for these materials often well before they are delivered, creating a cash flow problem, and what if the project is delayed? Will the owner accept and store the equipment when built and pay for it? Most likely not, but that is an option that should be seriously considered. Contractors on the other hand keep time sheets for work conducted and are paid for labor and materials received on site on a monthly basis. OEMs are not paid a penny for factory labor used in building the equipment each month and rarely paid for materials received in the factory.

Contractors and sometimes engineers often respond to OEM exceptions to LDs and unreasonable liability limits saying they are passing down what they have in their prime contract with the owner. Well, contractors and engineers need to show some guts and take exception to the contracts being passed to them by owners. In these times, nobody can guarantee meeting a schedule. Owners have to face reality and think of a different way to ensure contractors make their best effort to meet schedule and budget.

Currently, OEMs and contractors have a unique opportunity to change the draconian contract terms they have begrudgingly accepted for decades to terms that are fairer for all parties involved. If contractors and OEMs unite and show some gumption in objecting to these traditional one-sided contracts, OEMs may not need to be financing projects anymore and with better cash flows on projects, prices may actually come down, where lower margins are more feasible. That would be a win-win-win for OEMs, contractors and owners!

The comments and opinions in this post are my own and not those of my employer.