What makes the Solar CITIES Food-Waste-to-Fuel-and-Fertilizer the perfect STEM activity

The Solar CITIES’ “food waste to fuel and fertilizer” project is perfect STEM activity

And here I am.
Cheesy, huh? But fun!

Hi, I’m Dr. T.H. Culhane, a professor of Environmental Sustainability and Justice at the Patel College of Global Solutions at the University of South Florida, Tampa, and a National Geographic Explorer.

I spent 10 years as a hands-on science teacher in South Los Angeles, working with at-risk youth to try and reform our educational system by creating curricula that  blended  academic and vocational education, teaching at the highest level of Bloom’s taxonomy, and embracing each and all of our students’ multiple intelligences.

At Crenshaw and Jefferson and Hollywood  High Schools over that period from 1989 to 1992 we built solar stills to make alcohol fuel, which we called “Demonol – a fuel of the people, by the people, for the people” and converted a car  in the auto shop to run on it, And the students made a "movie trailer" out of the project (please forgive the bad quality; this was 1992 and the technology in the classroom was really primitive!)

We used bicycle generators and installed photovoltaic panels and small wind generators, built electric cars,  did community gardening and composting and urban tree planting, built composting toilets for urban apartments,  and trained our students through Digital Engineering for Multi-Media Occupations through a program we called “DEMMO Productions” to become like National Geographic film-makers so they could report with a fresh eye on how humanity can solve its biggest problems.

  I went on to teach Global Environmental Science at UCLA, while doing my Masters and Ph.D. field work in the rainforests of Guatemala and the slums of Cairo Egypt, (these pictures show me working at the Zabaleen trash picker's school in Egypt, teaching students how to build solar hot water systems from recycled materials so they could take their first showers with the residues of shampoo they would find in discarded plastic bottles they collected and shredded for sale)

I worked with the Office of Naval Research on  STEM Robotics curricula to improve opportunities for inner city schoolkids,

and spent the past four years teaching Environmental Science to low income students at Mercy College NY, working with returning military veterans and running our service learning trips to Israel, Palestine, the Dominican Republic, Brazil  and Jordan on initiatives to help refugees stay safe from disease and be resilient to disaster.

 In my off time or “vacations”,  I engage in what we call in our Sustainable Tourism program at USF, “Voluntourism”, travelling  on my own or on  National Geographic grants to places like Alaska, and Ireland,  South America,  Nigeria, Kenya, Tanzania, Botswana and Turkey, and Haiti, to name a few, to share with friends around the world how to do what the French call  “bricolage” – Do it yourself systems for improving what we call the “FEW Nexus” – the Food Energy Water nexus – to meet the United Nations 17 Sustainable Development Goals.

The common thread between all these activities, uniting Food, Energy and Water and helping ensure food security, is sharing ideas for  how to safely and productively manage the one thing we ALL have in common:  Kitchen Waste and Toilet Wastes.

Kitchens and Toilets bind us together into a common humanity.  They are the two domestic spaces that everyone needs to survive.  They use the most water and energy and they produce the most waste, the most air pollution, the most water pollution, the most contamination of the land and landfill.  Indoor smoke inhalation for kitchens burning firewood, charcoal, kerosene and propane around the world kills millions of women and children each year, also  causing devastating wildlife extinctions and deforestation and the consequent floods and soil erosion that I saw in Haiti this week after the Hurricane.  Contaminated water because of toilets claims thousands of lives because of cholera, typhoid and dysentery, all of which have hit Hait hard, while the improper discharge of waste water breeds mosquitoes that carry malaria and Zika.

 When you think about it, the problems created by those two areas in our households and schools – kitchens and bathrooms -- constitute some of the greatest threats to humanity that we have ever faced.  But, thankfully, these threats actually unite us, because unlike chemical poisons and radiation and war or terror, they are the only problems not only that each and every one of us has, on a daily basis, everywhere on the planet, whether up at the top of the world, here near Mount Everest in frozen Nepal where I was doing a National Geographic project in 2010 and 2011, or down here in my backyard in sweltering hot Tampa, but apparently the only major world problems that each and every one of us can SOLVE!

You know those books like “50 simple things YOU can do at home to help save the planet”?  Not one of them lists the solutions I spend my career and private life implementing.

But the good news is, they are actually the simplest and most effective of all the things I’ve studied and taught.

So now imagine with me:  Imagine you could engage in a STEM activity with your students and with your own kids at home that had the power to save every one of those 4 million women and children who die every year from dirty cookstoves?  Imagine you could share a STEM lesson plan which could virtually eliminate the loss of wildlife habit and trees that has turned places like Haiti into such a nightmare.  Imagine if you could do something in the classroom in miniature which, if scaled up, could eliminate more than 90% of the problems associated with landfills, particularly the climate altering methane emissions, but also all the smells and rats and vermin and feral animals.

Did you know – you did didn’t you? – that America alone produces more than 36 million tons of food waste every year, and that the EPA estimates that if we converted just half of that into energy rather than letting it rot, we could provide enough electricity for over 2.5 million homes.  But what you may not have known until today  is that every home can, safely and efficiently, convert their own food waste into fuel and fertilizer, enough to meet all your cooking and gardening needs. 

This video from our partners at Home Biogas in Israel  who made the unit in my backyard here in Florida, and my Solar CITIES NGO  Vice President basement in Pennsylvania and my communication directors greenhouse in NY, explains:

This technique is actually so simple that in my Non-profit organization, Solar CITIES, we consider the transformation of things like banana peels and orange and lemon rinds and avocado skins and pits and all that stuff  the literal “ low hanging fruit” in sustainable development.  And you don’t have to be a professional to do it, and yes, you can try this at home or at school.

It makes an amazing STEM activity and what I would argue is the most important STEM activity that we can imagine.   It certainly unifies Science, Technology, Engineering and Math.  In Science it neatly demonstrates ReDox reactions and acid-alkalinity and buffering and logarithmic  pH measurement; in biology it is pure applied microbiology, it is fermentation, it is speciation and biodiversity and trophic cascades, it unites botany and agriculture and biofuels.  In Physics it is fluid viscosity and thermodynamics and biofuels and carnot efficiencies and entropy and enthalpy; in the social sciences it can be used to teach cultural anthropology and political ecology and public policy, exploring why China and India and Nepal and even Kenya have been teaching and doing biogas for half a century, while we in the US are just beginning. A home or community scale biogas project also lends itself to GIS mapping and spatial analysis, exploring on the map where systems are successful and where they fail to get an idea of regional cultural reasons for adoption or rejection of this important technology.  And as a technology and engineering activity it is at once the most accessible and easiest to produce in the classroom or as a home project, since the basic core technology can be built out of anything that can hold water – from paint buckets to water tanks to cement or brick pools, and a few plumbing pipes, challenging budding engineers with the most cost effective and efficient ways to move solids in and get liquids out and store the gases and use them, while from a technological standpoint it can be jazzed up to include the latest and most exciting computer hardware and software.

  In our Solar CITIES education curricula we work with our robotics students to outfit the digesters with Arduino mcirocontrollers and Rasberry Pi microcomputers running C and Linux, coded by the students kitted out with ds18b20 waterproof temperature probes and pH sensors and 3D printed tipping cup gas sensors designed and printed by the students… the systems can be fully automated with servos and solenoids run by apps using remote sensing or by artificial intelligence to gather data and increase efficiency.  And when it comes to math, we graph all that data in Excel spreadsheets or SPSS statistical software and generate graphs.  The quantitative reasoning and analysis portion of this project can bring in every possible math-science skill set.  And it is meaningful, current and important.  It represents real applied science desperately needed for problem solving immediately.  It isn’t just a textbook exercise. As a Google Science Fair judge for the past 6 years, I can say that it makes one heck of a science fair project.  There are new frontiers of science to be explored with the “food-waste-to-fuel-and-fertilizer solution in the food-energy-water nexus.  That is why I , as a National Geographic Explorer and educator, devote so much of my life to it.

But you don’t have to have a Ph.D or be a PH.DO like me to get involved.

4 years ago, when I flew  in to Washington DC to work with the Office of Naval Research I got an email just as I checked into my hotel at midnight, from a student from the Washington Math Science Technology Magnet. The email said “Dear Dr. Culhane – I read about the work you do with National Geographic in Africa  in our Cengage textbook on Natural Science and, as a young African American woman who loves science, felt inspired to write you. I wanted to know if you ever come to Washington if I could meet you and learn more about how I could get involved.  My dream is to learn these technologies and travel to Africa and help save lives”.
I answered her immediately saying that serendipitiously I had just arrived in Washington from Europe and actually had the jet lag day free to rest until a 5 pm meeting and would be happy to meet.  Within 10 minutes a reply came from the vice principal of the school who had received an excited email from the student, and she invited me to come spend the day at the school.  So the next day I took a bus – I always ride public transit when I can, or ride a bicycle – into the inner city and met with the students and science teachers and we hatched a plan to build a demonstration biodigester at the school.  Within a few weeks they had the materials ready and I was able to get my  former Egyptian student Moustafa Hussein, who also serendipitously  happened to be visiting the US pursuing an internship in Washington – to spend a few days at the school sharing techniques for building the
digester.

As another example, last year , in Amish country in Lancaster Pennsylvania , 10 year old Clayton Young and his friends decided to explore homebiogas as their local  science fair project entry and came home winners.  Their experiment, which I replicated at my own house  -- because good science must be repeatable – was to engineer a bathroom based toilet waste biodigester system for their house and prove it could be done safely, cheaply and without odor.



Fortunately, as part of a home schooling community who use each other’s homes as their school classrooms, they had very enthusiastic parents and their science supervisors.  They invited me out to Pennsylvania to spend an afternoon with them getting started and then took it from there, showing that you can take an individual’s toilet wastes every day and turn it into a manageable liquid fertilizer and useful biomethane in the home, using home depot buckets as the core technology.  Their research helped corroborate work that I had started in my house in Germany and  other families are doing with us in New York and Pennsylvania and West Virginia, bringing the “food waste eating, fire breathing dragon” in out of the cold and into the home.

Because that is, in fact, what a home biodigester is – a domestic dragon.  You may have seen the film “how to tame your dragon”?  Well this is how!

Here are some of their results. http://rogueiq.wixsite.com/rogueiq/stem

And this work is having real impact.  We have now created a movement around the world, which citizen scientists from around the world  participate in on-line through our websites, http://solarcities.eu where we put our open-source tutorials and evidence from our builds, and http://biogascentral.net, where what we call the “blue flame community” puts up its builds and blogs and evidence and questions, and we have our open facebook group, Solar CITIES Biogas Innoventors and Practitioners, which is approaching 10,000 members and where we share all of our data freely to help try and create a world where there is no more waste.

 We call ourselves Solar CITIES, by the way, because we believe that the best way to achieve a solar powered civilization is to use the sunlight we all throw away and that is available for free and is causing a nuisance and even killing people – food and toilet waste.  Yes, food and toilet waste are fantastic  forms of stored solar energy created through the process of photosynthesis and available 24 hours a day, day and night, rain or shine, and the fact that we haven’t been teaching kids to look at it that way is responsible for so much misery in the world, and we can correct that.  Our students can help correct that.

Perhaps most excitingly, students who participate in such research can actually get published in peer-reviewed scientific journals, a real great resume builder for college applications.  Here is Clayton, and his Mom, as co-authors in the paper I am presenting at Eciyes University in Turkey at the International Council on Alternative Fuels Conference this December.

And it isn’t of course, just about STEM, but STEAMM education – Science, Technology, Engineering, Art and Math and of course Music..

Starting back in 1989, when my students and I made our first melodic-mnemonic music video, the Classification Rap, and used to present  how music and video and art could be used to bring the textbook to life at National Science Teachers Association (NSTA) conferences, we championed the idea that, just like with National Geographic, one of the best ways to learn and promote science is to find ways to present science in exciting memorable ways.  So getting the word out about how effective the home and community biogas solution is involves harnessing students writing skills, writing scripts and poetry and song lyrics, and illustrating with art and imagery and animation and production.  As an example, here is a song we put together about biogas that shows some of the science behind it and the social consequences:

PLAY BIOGAS SONG