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From poop to power

You might be flushing away your future water, energy source.
ASU professor talks about mining your toilet water for energy.
December 10, 2015

ASU professor discusses advances in recycling dirty water, and harvesting its content

What happens after you flush the toilet is becoming a big deal.

In a just-published article in the science journal Nature, Arizona State University water treatment expert Bruce Rittmann and two colleagues propose a paradigm-shifting change in the treatment of wastewater, a shift they say could have a dramatic global impact. They outline ways to transition from conventional wastewater treatment, which removes contaminants and disposes of them, to advanced used-water resource-recovery methods that would be environmentally and economically advantageous.

In other words, your dirty water could be mined for useful and valuable resources — like nitrogen or phosphorous. 

The technologies for doing this are being explored today, but challenges remain before they can be used on a large scale and meaningful way. Rittmann, an engineering professor in ASU’s Ira A. Fulton Schools of Engineering and director of the Swette Center for Environmental Biotechnology in ASU’s Biodesign Institute talks about the new methods and what they can provide.

Question: These sound like very attractive and potentially useful technologies. Why aren’t they being implemented, or at least developed further, now?  

Answer: For decades, the conventional thinking was that anaerobic treatment processes are not efficient enough to treat domestic wastewater due to its low organic concentration and low temperature. Also, conventional aerobic treatment (e.g., activated sludge) has served us well as a means of “treatment only.” Only in recent years have we begun to question the assumption that the only goal is “treatment.” Since conventional processes did their assigned task well and energy costs were relatively low (most of the time), we didn’t have the impetus to do anything different.

In the past 10 years or so, a pull to reduce energy and to limit the greenhouse gas costs of treatment has changed our perspective. Combined with new materials (membranes and electrodes), we now have new tools to “push” development and to complement the “pull” of the desire to reduce energy and greenhouse gas impacts. The same reasoning exists for nutrient recovery — no “pull” until recently, and some new materials to give it a “push.”

Q: What are the environmental benefits of these technologies?  

A: By shifting from energy negative to energy positive, the anaerobic technologies seriously reduce the greenhouse gas emissions of treatment. Recovering nutrients prevents their discharge into surface waters and thus minimizes the acceleration of aging and dead zones in our lakes, reservoirs and oceans.

Q: What are the economic benefits of these technologies?  

A: The anaerobic processes can be used to generate energy not consume it. Electricity use is the largest non-personnel expense in treatment, and shifting it from a cost to a profit center has a huge economic benefit to a municipality. In addition, the anaerobic processes generate much less sludge that has to be treated and hauled off to the landfill. Currently, sludge treatment and disposal constitute the second largest operating expense. Recovering nitrogen and phosphorus also can provide an additional income stream if the quality of the products is good enough to sell. At a minimum, the sale of nitrogen and phosphorus products should offset the costs of removing them.

Q: What is the next step needed to convert wastewater treatment plants into resource generators?  

A: On the technology side, various technologies are at different stages. An anaerobic membrane bioreactor is pretty well advanced and in large-scale testing now. It should be ready to go full scale soon. The phosphorus- and nitrogen-recovery processes are commercially available for other applications, but need to be optimized and tested for nitrogen and phosphorus recovery from anaerobically treated effluent. The microbial electrochemical cells are at the pilot stage now and need significant development.

The most important steps are less technical and more economic and policy oriented. First, municipalities need to realize that they can dramatically reduce their costs of treatment and make their operations much more sustainable through these methods. They have to get out of the “business as usual” mindset. Second, society has to embrace using resources that are recovered from “used water.” They have to see that the economic and sustainability benefits are huge, and they have to break down regulatory and other barriers to using recovered materials. Third, we need markets for most of the outputs. While energy can be used internally to run the facility, the good outcome of being an energy exporter requires that the exports be valued in the market. Markets now are poorly developed or non-existent.

Q: Why is government involvement in this effort essential?  

A: We need the government to support research, development and large-scale testing. These are the essential risk-reduction steps to spur implementation of “disruptive technologies.” Also, government often will need to create policies that encourage recovery instead of suppressing it. These can include eliminating regulations that ban or disfavor recovered materials, as well as actively promoting early adoption, like with tax credits or even grants (or low-interest loans) to communities to install recovery technology.

Q: Even with solid R&D on these technologies, what about public acceptance? Is this a formidable barrier that needs to be overcome?  

A: The public has little idea what goes on with what they flush down the drain. They also do not know the costs of conventional treatment, economically or environmentally. I think that the public needs to learn that a sizable municipal cost can be eliminated by recovering these resources. They will be pleased to pay lower user fees because of it, and most will be very pleased to know that they are making their town more environmentally sustainable.

Director , Media Relations and Strategic Communications


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Ready to heal the world

After a lifetime of helping, new ASU grad is ready to heal the world.
ASU grad understands helping people is more than making herself feel important.
December 10, 2015

New grad fueled her passion for social justice at ASU

Editor's note: This story is part of a series of student profiles that are part of our December 2015 commencement coverage.

When she was a child, Kaitlyn Fitzgerald took on the responsibility of helping to heal her family. As a new graduate of Arizona State University, she is setting her sights on repairing the world.

Since high school, Fitzgerald has devoted her life to social justice — helping refugees and those in need in Phoenix and beyond.

On Dec. 14, she will give two commencement addresses — as the student speaker for Barrett, the Honors College, and as the outstanding graduating student at the W. P. Carey School of Business. She will earn two degrees — in global studies and in business/public service and public policy.

Fitzgerald said her speech at the W. P. Carey ceremony will touch on “The Lorax,” the Dr. Seuss book that includes the line: "Unless someone like you cares a whole awful lot, nothing is going to get better. It's not."

That’s a concept that she has embraced since her childhood in Gilbert.

“My mother was diagnosed with Parkinson’s disease shortly after I was born, due to complications in the pregnancy,” Fitzgerald said.

“Growing up, I was the primary caretaker for her. That forced me to mature a lot quicker than a lot of my peers.”

She monitored her mother’s medication, did much of the housework and helped her mother get around.

When Fitzgerald was in fifth grade, her 23-year-old brother died suddenly.

“Trauma and stress can make Parkinson’s progress faster. We were all going through a lot having lost him, but at the same time there was not really any time to grieve.

“I needed to be strong and responsible and to help pick up the pieces. That was the mindset I had as a kid. It was isolating.”

She read a lot, drawn especially to stories about young Jewish people during the Holocaust.

“Everyone thought it was morbid but I thought that if these people were going through so much more than me, I could do it.”

A turning point came while Fitzgerald was a student at Seton Catholic High School in Chandler and she read “A Long Way Gone: Memoirs of a Boy Solder,” by Ishmael Beah, the story of the author's life during the war in Sierra Leone and how he escaped.

She was shocked.

“I had thought that the difficulties and challenges and injustices of the world were in the past because after the Holocaust we said, ‘never again,’ right?

“That was when I realized there was a lot more work to be done and I would dedicate my life to doing the work to make the world a better place.”

Fitzgerald continued to read about Sudan and child soldiers, and she won second place in a fundraising contest to benefit the Arizona Lost Boys CenterThe center was established in 2002 to resettle and support “Lost Boys” — young refugees who were fleeing civil war in Sudan. In 2011, the center was renamed The Lost Boys Center for Leadership Development. in Phoenix.

“They gave us a cash prize for fundraising contest, which I thought was ludicrous so I re-contributed my prize and submitted paperwork to be a volunteer a few months later.”

The program director called, asking if she would like to teach English as a second language.

“I said, ‘You know I’m in high school, right?’ "

They were fine with it.

Unhappy with the lessons being taught, Fitzgerald redesigned the program and arranged for ASU students and retired teachers to help at the center.

“That’s how my boyfriend won me over — by volunteering with me,” she said.

Along the way, Fitzgerald learned some of the pitfalls of volunteer work.

While still in high school, she visited a small village in Ghana.

"The experience was transformational, but at the end of the two weeks that we spent plastering the classroom building, I realized that we were wasting resources by being there.

“We were there because we claimed to want to make a difference, yet we spent so much money to fly there and be cared for there — money that, had we directly invested into the project, would have resulted in more classrooms.”

After that, she launched the Anidaso Project, which buys handmade bags from a Ghanaian entrepreneur and sells them to fund scholarships for children in Ghana.

With her life already devoted to social justice, Fitzgerald got into her “dream school” of the University of California, Berkeley. But she was devoted to her family and her work in Arizona.

“I was still working with the Lost Boys, and my time with that organization was not through yet and I knew it, so I decided to see where ASU would take me.”

As it turned out, it took her to the passion of her life.

“When I walked into Changemaker CentralChangemaker Central is an organization that provides resources and opportunities for ASU students to create social change., I was mesmerized by the work they were trying to do, showing every student at ASU the potential they have to change their community and the world,” Fitzgerald said.

She became the student director for her sophomore and junior years, and during that time the group grew from a handful of students to more than 100 at all four campuses. Changemaker Central won the prestigious Ashoka U-Cordes Innovation Award in 2013 for its student-led initiatives.

After her terms as director of Changemaker Central, Fitzgerald took a job as the communications and logistics specialist with the MasterCard Foundation Scholars Program, which provides scholarships to students from Africa who commit to returning and improving their communities.

Kaitlyn Fitzgerald and Lilian Ngweta

Kaitlyn Fitzgerald works with MasterCard Foundation Scholar Lilian Ngweta. Photos by Deanna Dent/ASU Now

She also studied abroad in Jordan and Palestine, and will earn a certificate in Arabic along with her two degrees.

Fitzgerald had an opportunity to work in Washington, D.C., but her devotion to her family kept her in Arizona while she decides her next move. Eventually, she says, she would like to get an MBA.

"I’m not completely sure what the world needs from me,” Fitzgerald said, but she is unwavering in her passion for helping humanity.

 “I credit where I am right now completely to ASU, to the fact that it gave me an opportunity as a sophomore to have my dream job, and to work side by side with deans and vice presidents and to be in the conversation that students at other institutions are not allowed to be in.

 “The fact that I believe we will make the world better I credit to ASU.”

Mary Beth Faller

Reporter , ASU Now