Saturday, April 23, 2016

The Miracle of Life... in Digesters!

RadioLab’s program Cellmates this past week was mind-blowing. UK biogeochemist Nick Lane put forth the hypothesis (The Vital Question: Energy, Evolution, and the Origins of Complex Life) that the explosion of multicellular life some 2 billion years ago was a singular event in Earth’s history, an event of vanishingly small probability, having never again occurred over the 2 billion years. This event was the merging of an archaea-type organism and a bacteria-type organism, resulting in a successful, collaborative union. This solitary union, a singular event, gave rise to all plant and animal multicellular life on Earth, from ferns to jelly fish to me. What is more, the chance of such a collaboration is so improbably small that it might not be expected to occur anywhere else in the universe. At least, that is how I understood Dr. Lane.
The improbability of multi-cellular life is, in my mind, even more mind-blowing than the explanation of the origins of life itself, put forth by George Mason University earth scientist Robert Hazen in his Great Courses lecture series (The Origin and Evolution of Earth: From the Big Bang to the Future of Human Existence). Hazen describes a global oceanic soup replete with nucleic acid polymers, formed by chemical reactions on reactive minerals surfaces, existing for a hundreds of million years, in which by an exceedingly rare chance event a self-replicating “living” DNA strand was formed, which then exploded across the face of Earth. This emergence of “life” occurred some 3.5 billion years ago, evolving over some 1.5 billion years into a soup of prokaryotic cells, many within the remarkable kingdom of life, Archaea. Also in that primordial soup were Bacterium, that other great “domain” of single-cell, non-nucleated prokaryotes.  It was the merger of a single archaea organism with a single bacterium of which Dr. Lane spoke on RadioLab.
Archaea… this is the kingdom that includes the methanogens we have embraced with child-like enthusiasm, as evidenced at our recent WEF specialty conference in Milwaukee.  I am probably the only one who stepped back from our profession’s precious attention to biogas and contemplated with wonderment that human beings are a highly evolved form of a bacteria-infected archaea cell.
Archaea are indeed pretty special.  We have learned a lot about them since science first uncovered their existence four decades ago.  But I believe we have many surprises ahead for their potential role in wastewater and biosolid treatment.
Between papers at Milwaukee, I rudely poked my head over the shoulders of Josh Mah, PhD candidate from Virginia Tech, and Peter Loomis, CDMSmith, both working with DC Water’s digesters, as they pored over charts of qPCR results of sludge samples from within DC Water’s digester start up. Communities of archaea and bacteria are still evolving inside those new DC tanks, and with that evolution comes the possibility of directing their path into highly-effective methane-producing communities. For Mah, this is a task still in need of financial support (hint, hint). Nearby in that WEF conference room sat Marquette’s professor Daniel Zitomer, a key researcher into the biology of digesters, and the first person from whom I learned several years back that each digester harbored unique microbial populations. We are still in the infancy of our understanding the significance of this observation.
Just as the key to life on Earth was the unlikely joining of cells, so too is the key to WEF’s Residuals and Biosolids Technical conference the unlikely joining of biosolids insights.  AECOM’s Bill Barber displayed a provocative PowerPoint slide (given in his presentation April 6, 2016, Session 14, 9 AM, “Alternative Configurations of Anaerobic Digestion and Thermal Hydrolysis To Enhance Performance”) equating the use of thermal hydrolysis with digesters to that of a Model T Ford decaled with racing flames. I had an “Ah-Hah!” moment when Barber pointed out the wrong-headedness of our industry’s practice of continuously overflowing slow-growing, hard-working archaea methanogens out of the anaerobic digesters, in contrast to our careful cultivation of activated sludge bugs. So, this put an exclamation point to the reasonableness of Alan Cooper’s proposal to use recuperative thickening (April 6, Session 14, 10 AM, “Achieving Advanced Digestion Using Recuperative Digestion Options”), in a return of both bugs and organic food to the digesters.  The “over-the-top” attention at the WEF conference for co-digestion makes more sense now to me as a way of balancing the nutrient and energy needs of archaea organisms in the digesters rather than as a way of boosting electricity production and struggling with waste heat.
Microbial science is the future of biosolids and, more generally, wastewater treatment.  The inquiry is clearly international and has burgeoned forth in the scientific literature over this past year. I already mentioned Marquette’s Dan Zitomer.  His 2015 paper “Relating Methanogen Community Structure and Anaerobic Digester Function” demonstrates the immediate relevancy of this microbial work: “nearly identical digesters can produce more methane than others because the microbial communities are more suited to produce methane rapidly.“ In a similar vein, Japanese researchers say it straight away in their article title: Canonical correlation analysis and variance partitioning analysis implied that bacterial and archaeal community variations were significantly affected by substrate and the operation conditions.  An Italian team explains “the applied method is suitable to describe microbiome into the anaerobic reactor, moreover methanogen concentration may have potential for use as a digestion optimisation tool (Traversi, et al. Application of a real-time qPCR method to measure the methanogen concentration during anaerobic digestion as an indicator of biogas production capacity.)  A Chinese researcher team asserts that “[t]he knowledge garnered would facilitate to develop more efficient full-scale anaerobic digestion systems to achieve high-rate waste sludge treatment and methane production” (Dissecting microbial community structure and methane-producing pathways of a full-scale anaerobic reactor digesting activated sludge from wastewater treatment by metagenomic sequencing).  
This current research on the microbiology of anaerobic digestion soon may have direct impacts on process design.  Again, Bill Barber, who is back in the States from a stint in Australia, explained in his review presentation in Milwaukee that superior sludge digester performance occurred with the sequencing of mesophilic digesters, even when compared to pre-treatment with thermal hydrolysis. That this effect aligns with the emerging science of microbial populations is borne out by research in Singapore. The research report Determination of the archaeal and bacterial communities in two-phase and single-stage anaerobic systems by 454 pyrosequencing  evaluated the microbial communities of “2-Phase anaerobic digestion (AD), where the acidogenic phase was operated at 2 day hydraulic retention time (HRT) and the methanogenic phase at 10 days HRT.” 
The application of microbial science will also help with co-digestion.  A recent journal article reported on an 18-month long monitoring period for a co-digestion facility by a Welsh team: “Monitoring methanogenic population dynamics in a full-scale anaerobic digester to facilitate operational management.” The message for me was that without use of new tools for studying microbial communities, our foray into co-digestion will be sub-optimal and trial-and-error at best.

I have no doubt that the future design and operation of anaerobic digestion and co-digestion at wastewater facilities will be dictated by new scientific tools that measure and monitor the behavior of microbial communities. The engine of these communities are microbes that are newest to our understanding of the evolution of life on Earth, and newest to our understanding of sludge digestion, but among the very oldest on Earth, the Archaea. Oh my, the life in biosolids is a miracle!

Saturday, February 1, 2014

Becoming Part of the World Consciousness

Krista Tippett featured commentators on Telliard de Chardin, a French Jesuit geologist, who presaged the Internet in predicting the potential for a global human consciousness. He interpreted human consciousness as an event on par with development of life itself on Earth as a phenomenon of galactic significance.

Imagining today the significance of the stress of nine billion people on Earth in 2050 is a necessary aspect of the global human consciousness if we as a species have any hope of avoiding catastrophe of disease, warfare, and pollution arising from abuse of natural systems.

The individual challenge is for us to be mindful that we are each part of the evolving human consciousness. Might I be so bold as to assert that those of us in the humble service of recovering resources from wastewater can make and defend our case that our's is an example of a future that works. We are doing it today, and we must boldly set ourselves in the camp of those who advocate for a sustainable future in which all peoples live with fulfillment and health.

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Wednesday, March 23, 2011

Innovations in the Biosolids Fields

A “fevered pitch” may be a bit hyperbolic a description for technology advances in biosolids stabilization. A review of the agenda at recent conference will reveal a swing toward advanced digestion and chemical treatment processes to improve pathogen destruction, biogas production, and odor reduction. Yet, articles on our fundamental mission area, land spreading of biosolids, have almost disappeared. So it is a good thing to read that breakthrough new approaches are being studied for delivering solid byproducts to soil for crop fertilization in new ways.

Those of us engaged in biosolids application to farm fields have shared some concern for the uneasy relationship between agricultural practices associated with no-till and conservation tillage and the use of biosolids. No-till farming achieves the protection of soil structure and soil infiltration capacity, but at the expense of reliance on aggressive chemical weed control. Biosolids on such no-till fields may be surface applied, as are manures in the same practice, but with the risk that nutrients and organic matter might be carried to surface waters during heavy storm events.

The drive to address the issue of solid manure spreading while minimizing risk of environmental releases has been focused in sensitive watersheds, notably those within the Chesapeake basin. The drive has produced innovation. And reports of successful new approaches are now being released.

A recent JEQ article (see; discusses novel manure application methods to reduce N and P losses in no-till systems of agriculture. This article introduces the positive qualities of a new subsurface applicator for poultry litter, which is the first subsurface applicator available for solid manures. The biosolids profession should be among early adopters of equipment that advances the goal of reduced nutrient losses while conserving soil structure.

PBDEs and Biosolids

A decade has passed since I first heard the term “PBDEs.” Having been intimately engaged in a response to illegal discharge of PCBs to Philadelphia sewers a few years prior, I had experience which informed my intuition that this class of compounds, disconcertingly alliterative with PCBs, would prove to be no friend to biosolids.

Science has now provided a picture of the exposures to PBDEs in the world environment. The recent issue of Environmental Science & Technology contains an article by David Trudel, et al, “Total Consumer Exposure to Polybrominated Diphenyl Ethers in North America and Europe” (Environ. Sci. Technol. 2011, 45, 2391–2397; It synthesizes an enormous body of work across the world and across ecological systems—water, air and land.

Trudel’s article sparked in me some sharp memories from a full ten years ago. In July 2001, against the backdrop of the crashing waves in Ocean City, MD, on an outdoor patio on which biosolids folks gathered to confer, Rhonda Bowen from Hampton Roads took a cellphone call from her boss. A researcher at the Virginia Marine Institute, Rob Hale, had a Nature magazine article reporting concentrations of a class of persistent organic pollutants known as “PBDEs” in sediments from the same watershed in which land application of biosolids had been practiced. Dr. Hale had intended to implicate biosolids as a source, although even with the meager information available to us on such pollutants, a meaningful link seemed farfetched. A response by the biosolids profession was needed. A full year would go by before the scientific community would see a thorough, peer-reviewed article sources and potential pathways of this class of contaminants (De Wit, C. A. “An overview of brominated flame retardants in the environment.” Chemosphere 2002, 46, 583–624. ).

The present article in ES&T, based on the vigorous response by the scientific community, has now put the issue in perspective. Biosolids is nowhere to be found in the article, as household dust and widespread atmospheric deposition on animal-grazed fields are now understood to be major sources.

I take solace in the observation that biosolids both concentrates persistent organics like PBDEs as well as concentrates the scientific community’s attention to emerging issues, like society’s use of high production chemicals.

Perhaps, the biosolids profession should take a leadership role in advocating responsible stewardship by industries in their choices for chemical inputs to consumer products that may persist in the environment. While the biosolids profession may be the unwitting recipients of the residuals from manufactured goods, all too often the profession takes the public blame for its presence in the environment. Against this tendency we need to have a strategy that deploys sound science and risk assessment, and one that anticipates, rather than merely reacts to, issues of public concern.

Friday, November 5, 2010

Free Heat?! It's Just Under Your Feet!

A match made in sustainability heaven?

The mayor of Philadelphia has declared that his city will be the nation's "greenest city." An extraordinary number of competitors vie for that distinction, with cities such as Portland, Oregon, having many more years than Philadelphia out of the starting gate.

But I experienced a rush of confidence that the mayor's claim of sustainability is not an empty boast. That confidence is tied to an eureka experience in seeing the "synergy," specifically an "effluential synergy," at play with two locally-owned companies.

Michael Sebright, a Chestnut Hill resident in Philadelphia, "creative officer" of Energy Reconsidered, has the right to use IsoMax Zero-Energy Building Systems in the United States. This technology sandwiches a fluid circulation system within interior building panels on exterior walls, in which the fluid is warmed or cooled by a heat pump from water sourced, in the standard model, in geothermal tanks and with energy from solar thermal panels. Got that? The wide experience in Europe is that solar thermal energy is sufficient to provide all the space heat needed, even in northern Europe.

The challenge to solar thermal in a city is the relatively small roof area typical of Philly row homes. IsoMax also requires installation of a geothermal tanks, which is complicated in a small rear yard or in a narrow basement.

So that kind of hurdle is where enters the second bright light on the horizon of Philadelphia sustainability ventures: NovaThermal Energy. This company has technology to extract heat from sewage flowing in the city's sewage collection system. Whereas a typical family uses 10,000 cubic feet of natural gas annually to make hot water, and it all quickly washes down the drain and into the sewer system, a vast quantity of inaccessible BTUs of wasted thermal heat is flowing in the 3,000 miles of sewers buried under Philadelphia city streets. But NovaThermal has a technology, now deployed in China, to "borrow" the sewage just long enough to pull out those BTUs. In doing so, NovaThermal uses, as does Energy Reconsidered, heat pumps to amplify the temperature of the fluid to put the energy into a form usable for heating building spaces.

NovaThermal's technology, championed by Chestnut Hill resident Elinor Haider, is still brand new to the city and to the U.S. In fact, just before Halloween a major first step to development of a "reference facility" in the States was taken. The company's web site announced a funding grant from the Greenworks Pilot Energy Technology Program for the installation of a system for heating a 20,000 square foot building at a Water Department facility using funds.

So here is my eureka moment!

We have here a match made in sustainability heaven. Let's combine the capability of the NovaThermal technology to extract heat from the sewer with the capability of Energy Reconsider's IsoMax to efficiently use sewer heat for building space heat. In this way, the BTUs in hot water drained from up-sewer homes gets a second chance to be useful in homes down-sewer.

Next step?

The saying goes: "many a slip between the cup and the lip." Nevertheless I recommend a conversation around a table at the Chestnut Hill Coffee Company. Can you imagine a more powerful result than having a carbon footprint for home heating that is actually in the opposite direction? Now that is sustainable!

And, for me, this is a compelling "effluential synergy."

Friday, July 23, 2010

Save the Bay. Eat Beans!

We learned today that Harry Reid has hung it up on climate change legislation. Cap-and-Trade is over for this session of Congress. Any how, the economy has faltered so badly that our country’s emissions of GHG, I mean greenhouse gases, have probably come down from the weight of our new impoverishment.

For me this really is a relief, because I found getting really worked up about GHG control hard to do. As for Cap-and-Trade, I had always preferred the even less politically tenable carbon taxation approach.

I am ready for a change. Not change, as in climate change. I mean a change in the focus of attention away from climate-changing gases.

I am ready to focus on what I have for long believed is a more serious environmental issue than the emission of carbon dioxide from fossil fuels.

Do you want to hear it?

Mineralized nitrogen, as in ammonia and nitrate nitrogen. Mineralized nitrogen was the key driver for the dead zones in the Gulf of Mexico long before the recent oil well fiasco. Mineralized nitrogen is damaging the Chesapeake Bay when washed off of confined animal feed operations. Mineralized impacts local streams when ammonia-laden rainfall drains away. Mineralized nitrogen acidifies forest soils when the ammonia is converted by soil organisms to nitric acid. Mineralized nitrogen contaminates groundwaters, cauing build up to unhealthy level of nitrates that are a health risk to babies.

I have always been fascinated by a few factoids about mineralized nitrogen. First, the catalysis of nitrogen and hydrogen gases into ammonia is a technological invention from the opening of the Twentieth Century of revolutionary scope. Messers Haber and Bosch, in their process of nitrogen mineralization, for which they independently received Nobel Prizes, unleashed the conversion of stable, abundant atmospheric gases into ammonium nitrate for use as explosives for modern warfare and to ammonium nitrate for use as fertilizer for the “green revolution.” In one great miraculous invention, humanity developed the capacity to support precipitous growth in populations through cheap fertilizer and to mow them down with horrendous efficiency with cheap firepower.

But the other fascinating factoid is the tremendous ecological alterations that are underway inexorably as a consequence of the incessant release of ammonia to the air, land and waters, causing permanent changes to the environment. In one article, a reported 90 percent of all of the manufactured mineralized nitrogen produced for agricultural use is dispersed to the environment and never enters into intended crops and animals as nutrients protein.

There are no coincidences… or are there?

The same day I learned that carbon legislation had been shelved in the US Senate I learn that Water Science & Technology, a peer-reviewed journal of the International Water Association, had published a science article on an approach to management of nitrogen in watersheds that in my 35 years of environmentalism I had failed to so clearly distinguish.

The new watershed strategy? Vegetarianism! Or, at least greatly reduced meat consumption by a region’s inhabitants.

The journal article is entitled “Considerations on the importance of nutrition habits for the national nitrogen balance of Austria,” by Matthias Zessner, Simon Thaler, Katerina Ruzicka, Stephanie Natho and Helmut Kroiss. It will be published this week (WS&T, Volume 62.1, 2010, pages 21 to 27).

The authors, in their best scientific style, assert in their opening sentence: “The anthropogenic nitrogen turnover of Western societies is highly unbalanced.” This means that modern society releases far more nitrogen to the environment when it grows food than it takes in as protein in the food it eats. The biggest culprits are the high nutrient inputs to the raising of cattle and poultry and the extremely low proportion of mineralized nitrogen that ends up in the animal protein sold at supermarkets.

Their recommendation: “a shift from the actual animal-based nutrition to a “healthier nutrition” (mainly characterised by 2/3 vegetable protein supply) would lead to a reduction of needed nitrogen supply as well as of nitrogen emissions to the environment by about one quarter to one third on a national scale.”

So, here is a thought! Senator Reid has left US EPA administrator Lisa Jackson in a real bind by having her negotiate, without good political cover, the minefield that is carbon dioxide emission regulation. But let’s have Ms. Jackson scrap even the pretense that bold new regulations are going to be promulgated on carbon dioxide.

Carbon management is passé. Nitrogen management is the new thing.

The article in WS&T holds the key. We need to derive our dietary protein from plant, not animal, sources. Ms. Jackson should go to her natural liberal constituents in the vegan/vegetarian communities, join forces with the radical PETA groups, and develop new alliances with certain cliques within the conservative USDA and FDA, and come out with a major campaign promoting vegetarianism as the greatest of all watershed management tools.

So no longer is our heavily meat-laden diet merely an issue of heart disease, diabetes and stroke. It is an issue of even greater importance -- eutrophication of lakes and ponds and dead zones in bays and estuaries.

Now there is an issue that I can get excited about!

The US EPA will finally be able to connect to people in a way that is as immediate as the plate of food on their table. For it, the EPA needs a new slogan.

Ms. Jackson, try out: “Save the Bay. Eat Beans!”

Wednesday, July 14, 2010

Peacable Kingdom? Think 'colon'!

I have just read a beautiful, reassuring story of a world that is “largely unexplored,” a “microbiome” of organisms living a “settled existence,” in a stable state and in symbiosis with each other.

Where is this world? My colon!

So writes Amy Maxmen, in an online article today, “The gut's 'friendly' viruses revealed,” discussing the work of Jeffrey Gordon at Washington University in St Louis, Missouri, published in Nature Magazine (Reyes, A. et al. Nature 466, 334-340 (2010).) Maxmen’s article is at

Maxmen reports: “More than 10 trillion bacteria normally inhabit the gastrointestinal tract…. Within and among these bacteria live bacterial viruses, or bacteriophages…. [F]aeces from each individual carried a distinct viral community that varied by less than 5% over the course of a year. The bacterial viruses also appeared to mainly be lying low as 'prophages' rather than multiplying and killing the bacteria they infect.”

Further, “[I]t could be that viruses are the real drivers of the system because of their ability to modify the bacteria that then modify the human host…. Because human nutrition partly depends on the relationship between bacteria and their viruses, understanding the dynamics of that relationship might yield treatments for obesity, allergies and other maladies."

The author ties the nature of the bacteria and viral relationships back to the necessity of encouraging development of a rich “human microbiome.” Maxmen says, “Indeed, the rise in the incidence of food allergies in Western societies has led to hypotheses that extreme hygiene disrupts the ability of microbes to colonize human guts, resulting in a lack of tolerance to usually harmless foods.”

I knew instinctively, even as a small child, that my grandmother was right when she said “you have to eat a pound of dirt before you die,” by which she meant, and I understood her to mean, there is nothing wrong with getting dirt in the mouth.

Since stable colon colonies are a good thing, I am glad I was never persuaded to undergo those colonic irrigations I have seen praised in the alternative health magazines.

Better yet, eat dirt!