Finding Value in Waste

There’s something beautiful about transforming disgusting castoffs into products that are useful, valuable, and healthful.

Thank goodness we are disgusted by human waste. Have you ever thought about that? The disgust response keeps us from approaching it as something interesting or valuable, which could pose a severe threat to one’s health. We flush it away, eager to get it off our mind as we enjoy the relief of satisfying nature’s call. But to plants, animal waste is just what they need and want: nitrogen, phosphorus, potassium. Plants also flourish with the carbon dioxide we exhale. Conversely, plant waste (namely oxygen), shed as a waste product of photosynthesis, gives the vital breath of life to our bodies. It’s all a matter of perspective. Human waste is just chemistry, after all; and it stores not only elements vital to plants, but a great deal of stored energy. Now, scientists are tapping into the potential in the smelly crap and pee that kids laugh about.

An interesting video on this was posted by Live Science. In “Pee to Feed the World,” UC Berkeley engineer William Tarpeh describes a device he has built to turn urine into fertilizer. Out of his concern of the millions of third-world people without access to toilets, he “reimagines” the untapped potential of urine to fertilize crops. The sale of fertilizer and the increase in food production, in turn, can provide funds to manufacture more toilets. Who would have thought that something we hasten to flush and forget could improve the health and prosperity of masses of people living in poverty and squalor?

But what about that smelly crap that is the bane of diaper-changing parents? What could possibly come from something so disgusting? Glad you asked. Now read Sid Perkins’ short article in Science News, “Human feces from the developing world could power millions of homes.” Sid, you’ve got to be kidding! He’s not. There is so much energy in fecal matter, it could lift the third world out of poverty, if it could be re-imagined (sans odor) into usable forms. Remember how pioneers gathered cow patties for their campfires?  Remember those who mined bat guano for fertilizer? The factoids in this article are stunning:

Almost a billion people in the developing world have no access to toilets and defecate outdoors (such as these children in Bangladesh). But that waste shouldn’t go to waste, a new study argues: Rather than tainting the environment and transmitting disease, it could actually be harnessed to heat or power millions of homes. If all the openly defecated human waste were instead deposited in latrines—and the sludge were then collected and heated in kilns at temperatures exceeding 300°C (572°F) to produce charcoal-like briquettes—it would yield up to 8.5 million tons of charcoal, according to a report released today by the United Nations University Institute for Water, Environment and Health. (Those poop briquettes have the same energy content, pound for pound, as coal, the researchers note.) Plus, if openly defecated waste were instead deposited in latrines and then fermented with methane-producing microbes in large tanks, the gas thus produced would be worth as much as $376 million and could be used to generate enough electricity to power an estimated 18 million households.

Systems to treat the waste could pay for themselves in a couple of years, the article says.

Friday November 19th is “World Toilet Day,” in case you want to plan your party. (Don’t be a party pooper, now.) Actually, it’s no laughing matter. The clean restrooms Americans and westerners take for granted are lacking in most of the world. That video on Live Science mentioned above begins with sad images of children living in squalor, where people relieve themselves outdoors and lack access to basic hygiene. Yet the very substances they eliminate daily, if harnessed intelligently, could lift them out of poverty and improve their lives. What a thought!

It’s a dramatic discovery that motivates some scientists and engineers to find ways to turn waste into value. It’s driving Francis de los Reyes, an environmental engineer at NC State University, to go beyond building toilets, PhysOrg says. He wants to find ways to process human waste into useful energy and fertilizer in a sustainable way. If he and his students succeed, the dismal pictures of frowning children, sick and starving, could some day turn into images of smiling, healthy, well-fed bundles of joy, eager to fulfill their potential.

Update 11/25/15: The Burlington Free Press posted a headline, “Pioneers of ‘pee-cycling’ tout urine’s value.” Now there’s a switch; something we hasten to flush out of sight has value? Yes; a lot of nitrogen and phosphorus that agriculture can use. “The phosphorus and nitrogen contained in an average adult’s daily urine output is enough to fertilize the production of a loaf of wheat bread,” a researcher says. It performs just as well as costly commercial fertilizer. If people can adjust their attitudes about this, we can expect to see new model toilets that can collect urine separately from feces, and actually collect both for processing and re-use. “Pee from healthy adults is virtually pathogen-free. It contains very few heavy metals. It’s relatively safe to handle, even by amateurs.”

To the Christian, “Everything created by God is good, and nothing is to be rejected, if it is received with thanksgiving” (I Timothy 4:4). Some things like good food are to be enjoyed with pleasure; other things are to be disposed of properly. We shouldn’t think of human waste as evil, but as something to be managed with care and good stewardship. Presumably Adam and Eve were taught, or knew instinctively, how to eliminate waste properly. God commanded Moses to keep a clean encampment when the army was out on the field (Deuteronomy 23:13); each soldier was to bury his waste.  Our Creator equipped us with the disgust response for our good. Some animals are not disgusted as humans are; rabbits will take a second pass sometimes on the pellets they cast off, and dogs return to their vomit, but it is normal and appropriate for humans to strive for bodily cleanliness.

The Lord has also given the human mind the creativity to turn castoffs into useful things. This is a great example. We wish the best for the scientists and engineers seeking to fulfill the lofty goal of helping third-world populations use their own waste as a resource to grow crops, heat their homes and gain prosperity in a clean, healthy environment. Finally, here is one positive thing the UN is involved in. Happy toilet day!