Dr. Glen Daigger reports back from the IWA Leading Edge Water and Wastewater Conference, which provided a significant focus on resource recovery topics.

By Dr. Glen Daigger, International Water Association President and CH2M HILL Senior Vice President and Chief Water Technology Officer

I have been traveling in Europe and especially enjoyed this trip as my wife Patty was with me. We have just been in Bordeaux, France for several days, first at our second quarter International Water Association (IWA) Board of Directors meeting and then the IWA Leading Edge Water and Wastewater (LET) Conference. We look to place the Board meeting adjacent to another event whenever possible, for obvious reasons.

This is the 10th LET Conference and I have been privileged to be at all of them as I served for many years on the organizing committee and now on the Board. LET brings together the leaders of the profession and presents both results and views on the leading edge of technology. This one was clearly one of the best as it not only reviewed on-going developments in the more traditional areas, but also provided a significant focus on resource recovery topics. Traditionally we think about recovering water, energy, and nutrients and have both well established and evolving technologies for doing so. Many exciting and successful examples already exist, suggesting that these concepts are no longer “leading edge.”

The conference pointed to some very significant changes occurring in the water industry. I will hit on some of the key ones.  First, autotrophic nitrogen removal by partial nitritation (conversion of ammonia to nitrite rather than nitrate) and deammonification (autotrophic denitrification via the Anammox route) is an established technology for treatment of the high ammonia streams from solids handling.  Moreover, it is expected to be the accepted technology for the main liquid stream within the next decade.  This will be transformational for wastewater treatment as it frees up the carbon in the influent wastewater to be captured for conversion into energy (biogas or directly into heat via combustion).  The result is that wastewater treatment will be energy positive.  Questions remain on the best way to capture influent carbon, either by direct anaerobic treatment or by capturing the carbon by chemically enhanced primary treatment or high rate biological treatment and subsequently anaerobically digest the captured solids.  Work to do, but a totally different direction than the profession has been following for decades.

The above addresses energy capture from the used water stream.  We also know that we can capture nutrients via struvite or calcium phosphate precipitation. What this conference also did was to suggest that other materials, such as inorganic constituents like valuable heavy metals, coagulants (which can then be recycled), and specialized high-value organic products, can be recovered. This is truly the frontier. How would one do this? Electrochemistry is one answer. Coming out of this conference I am going to buy a good book on electrochemistry (from IWA Publishing of course) to bring the principles of this science back into the center of my mind. We also learned about the significant advances occurring in biotechnology relative to the metabolism of inorganic constituents and how this evolving knowledge can be put to use. Some amazing things are happening which will be beneficial to our colleagues, those working especially on mining issues, but also on industrial and municipal treatment issues. Many new things are being learned about sulfur metabolism and their potential beneficial use. Of course, we are already touching on this through our biological selenium removal work and in projects like the Gippsland Water Factory where we are removing sulfur from pulp and paper wastewater as elemental sulfur. But, I was reminded that this is only the tip of the iceberg. So, those of you who thought that Anammox was the end, buckle up to learn some further new and fascinating things! We are in the process of re-inventing our profession!

It was also great to catch up with long-time friends and colleagues and to make new ones!

Read all of Dr. Daigger’s travelogues.