More Inconvenient Truths

In 2006, Al Gore made the headlines with the documentary An Inconvenient Truth. Now I have to confess I’ve never seen it, but having seen Mr. Gore in other settings, I’m not a big fan of him and probably never will.  That said, plenty of folks in the environmental world thought it was a timely film that was a clarion call to action to reduce greenhouse gas emissions to turn the tide on global warming before it's too late.  The fervor of the movement to reduce carbon emissions has ramped up in recent years, gaining political and popular momentum, some even calling it the "Biggest Threat Modern Humans Have Ever Faced" and other such hyperbole. Personally, I think it's a good idea to reduce our dependence on non-renewable energy sources (and other non-renewable materials for that matter), and to reduce particulate pollution from vehicles, but I'm not convinced that global warming is the biggest threat to our existence on Earth. My views on this have shifted over the years. The last book I read on the topic was quite compelling and worth a read: Lukewarming: The New Climate Science that Changes Everything: Michaels, Patrick J., Knappenberger, Paul C.: 9781944424039: Amazon.com: Books.

OK, so global warming may or may not be an inconvenient truth, depending on your viewpoint. What is evident to me as an environmental engineer is that there are several other truths that are even more inconvenient with respect to humanity's impact on the Earth. A few years ago I read a very interesting book called "The Human Quest" by Johan Rockström and Mattias Klum that presented the idea of planetary boundaries. The figure below summarizes their opinions nicely.  

Things shown in red are higher risk of causing problems beyond what the natural environment can handle, green are within the ability of the environment to deal with them, and the yellows are in-between with some uncertainty on their risk.  What's interesting to me, with all the press around climate change is that it's in the yellow zone for these guys, whereas biochemical flows for phosphorus and nitrogen are firmly in the red, along with genetic diversity.

As a wastewater guy, I'm not surprised by this as eutrophication caused by nutrient emissions have been a hot topic for as long as I've been a poop engineer, grey hair and all (I actually started my career doing research into biological nutrient removal).  What's a little frustrating is all the energy and media focus going into climate change when we have bigger problems and higher environmental risks posed by nitrogen and phosphorus and yet the media and the politicians doggedly focus on carbon.  Even within the wastewater world folks are spending their time and effort looking at "decarbonization" when the impact is probably less than 1% of all human emissions of CO2e - I even helped to write a chapter in a book on the whole topic! Shame on me, I guess.

I would love for there to be a bigger focus on phosphorus and nitrogen. Maybe with all the buzz about the "circular economy" thanks to the furor over climate change we'll take a closer look at how phosphorus and nitrogen are moved around the Earth, and the human impact on them. I dunno, I have a feeling the water industry will get sidetracked on plastics or PFAS or some other minor pollutant whilst we do very little to restore the nutrient cycle.

So what do you think?

Nutrients Part 2

Vancouver

My original plan was to step from Nutrients to Energy to Water week by week in thinking through resource recovery from wastewater treatment plants, but I want to dwell a little longer on Nutrients as this past week I attended the WEF/IWA Nutrient Removal and Recovery 2013: Trends in Resource Recovery and UseIt was a very good conference. Just the fact that this annual conference that started out looking at nutrient removal now includes significant space for recovery of said nutrients is an excellent step forward. Last Blog I listed what I thought were 3 significant hurdles to nutrient recovery, namely Money, Focus and Knowledge. This past week certainly brought Focus to the topic and considerable Knowledge too... to be honest there was so much knowledge shared I need to go back through the proceedings to see what I missed! This is excellent news in our move toward a sustainable future.

So that's the good news, but still there is the significant hurdle of Money. I want to offer the suggestion that we need to broaden our perspectives when it comes to looking at the finances of nutrient recovery projects. One very obvious example is the benefit that comes from removing phosphorus from a treatment facility that is suffering from pipe blockages and equipment failure due to struvite. I have heard of a couple of utilities that have decided to do phosphorus recovery in order to remove phosphate from their sludge liquors where struvite was a major problem. There is also evidence that sludges rich in phosphorus (due to enhanced biological phosphorus removal) are more difficult to dewater. Finally, the content of P in most biosolids produced in a treatment facility is much higher than it needs to be for agronomic use. Connect all of these factors together, estimate the cost benefits of them and then add this to the economic analysis for P-recovery and it will significantly shift the balance.

And all this is can be acheived without considering the true value of phosphorus as a non-renewable resource. Throw in this factor, and the fact that it's doing the right thing, then I think the case for nutrient recovery is much stronger than many may realize. I'm excitied to be working on a P-recovery project at Stickney in Chicago over the next several months. I strongly encourage others to consider doing it - the financial aspects are much better than you'd expect if you take an holistic view, and it's just the right thing to do, so do it!

 

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