Technology Spotlight: Aquaporin

We live on the blue planet, yet only 1% of the 'blue gold' is available to the 7+ billion people.

We all think desalination is the solution to our impending water problems. If we can somehow take the 97.5% of salt water and cost effectively desalt it, we will have enough water for everyone! But, this comes at a cost. The current technologies for desalination are expensive, not only in capital, i.e. to build treatment plants, but also require a lot of energy to operate. The most common desalination technology is reverse osmosis (RO), where we push water against a very thin membrane with tiny holes. (Think kidneys) These holes allow only water molecules to go through and leaves behind the salt (concentrate / brine). To push water against the membrane requires high pressure and hence is very energy intensive. However, it is interesting to note that the energy requirement for RO desalinated water has reduced by half over the last decade. This is primarily because membrane manufacturers have designed better performing membranes. The technology is about 65% efficient at this stage. It will be foolish to expect that we can achieve 100% efficiency in the next decade, as you can never get 100% efficiency in any technology. However, it is reasonable that we will be slowly edging towards 70-75% efficiency. Moore's Law will not apply to this technology, and further 'fine-tuning' of this technology will  yield diminishing returns.

So where is the innovation? Can we reduce the need for pressure all together? A Danish company is using biomimicry and embedding proteins in membranes that can regulate the flow of water. Ever wonder how mangroves grow in brackish water? How do they filter out the salts and absorb water? The protein is called aquaporin and it sits within cell membranes. In 2003, Dr. Peter Agre was awarded the Nobel Prize in Chemistry (which he shared with Dr. Roderick MacKinnon) for his discovery of aquaporins. These proteins are also in our red blood cells, kidneys, eye lenses, almost anywhere there is water transfer across membranes. The company, Aquaporin A/S, is currently working on developing membranes that will desalinate water by a very different mechanism from the current traditional RO methods, and possibly with smaller energy footprint.



This technology is still in development phase but shows great promise. The initial trials with NASA have proven quite successful. We wish Aquaporin A/S success in their endeavors, and look forward to their product in the market in the near future.

Australia and Singapore - How are they dealing with water problems?

Enclosed below is a presentation by Proteus at the Council of Water Managers on October 19th, 2010 at their Dinner Meeting.

Over the last couple years, I have been fortunate to be living in Australia while designing and building one of the largest recycled water plants in the world. During my stay in Australia, I was also managing a design team out of Singapore which required me to make frequent trips to Singapore. Thus I was able to observe the water management policies and programs in these two countries. By bringing these ideas to you, my aim is to promote a healthy discussion on opportunities here in San Diego County.

Desalination - US vs. Australia

It is interesting to note that over the last six years, Australia has been able to permit, design, and start construction on six major seawater desalination projects, and three of those plants are already in operation. That is amazing! On the other hand, desalination plants in the US tend to get embroiled in loads of problems, and California's first, the Carlsbad Desalination Plant, is yet to be constructed. It took ten years of planning and five years in the state’s permitting process to receive final approvals from every required regulatory and permitting agency in the state, including the California Coastal Commission, State Lands Commission and Regional Water Quality Control Board. After all that, every other week we still see lawsuits raised for one issue or the other, only to be struck down by the courts.

This makes one wonder - why is it such an issue in California and not so in Australia? Just like the Australians, Californians live on the coast and have very similar meteorological, environmental, and economic issues. (Oh yes, I know, I lived in Oz for couple years and have recently returned.) So what is going on?

The answer is in three parts:

One, California has not faced as severe a water shortage as Australia. Southern Californians can get water imported (transported) from the mountains at relatively cheap and subsidized rates; whereas, in Australia, when the reservoir levels dropped down below 21% in March 2007, it was a major crisis and projects got done.

Two, though California and Australia face similar environmental issues, the permitting process in California seems to be haphazard and irregular. There are several agencies regulating various aspects of the environmental regime and often there is no dialogue or synergy between the agencies, leading to excessive delays in the permitting process. Each issue is reviewed and judged by different agencies at different times! There is a desperate need of one supervisory authority that coordinates all the reviews.

Credit: WDR, Vol 46, No. 8

Three, project economics vary between the two regions. Projects in Australia are led by the centrally planned regional water authorities who spread the cost of the project over the entire service area. Here in California, the model adopted was of a developer led project, whereby the developer was guaranteeing the cost of desalted water would never exceed the cost of imported water. This later model gave a different dimension to the project and led to mistrust, suspicion, and even animosity against the 'private' approach and raised cries of 'lack of transparency' and complaints of 'aggressive behavior'. The general trend is that the public believes in the 'non-profit' nature of public agencies (even if they are sometimes fraught with inefficiencies) and tend to disapprove of developers.

So, where are we now with Carlsbad Desal Project? The project just broke ground on some initial sitework. Unfortunately, the lawsuits are still coming, check here for latest development on this project.

Also check out some interesting presentations on desalination at the 2010 Water Reuse Conference. My friend Joe Monaco and I will be presenting on Tuesday, March 9 at 2PM (Session C5).

Acknowledgment: Thoughts presented in this blog also appears in the Water Desalination Repot Vol 46, No 8, edited by Tom Pankratz, and is repeated here with the editor's permission.