From public composting toilets in San Francisco to street lamps powered by dog poo in Phoenix, 2011 saw an abundance of experiments to find new uses for human and animal waste. Here’s Earth911’s picks for the top 10 poo-cycling projects of the year, and we leave it up to you to decide: gross or green (or both)?
1. Panda poo fertilizes the world’s most expensive tea
An Yanshi, a university lecturer in China, found a way to recycle panda poo this year, securing a patent to use the animal waste as fertilizer for a tea that will sell for as much as $36,000 per pound.
An says that using panda-poo fertilizer has health benefits for tea-drinkers: The excrement is rich in fiber and nutrients, and An claims that its bamboo content contains anti-cancer properties.
2. San Francisco considers public composting toilets
While the “City by the Bay” debated rolling out composting toilets to homes and businesses citywide, two San Francisco community groups worked with an eco-minded laboratory to design a portable composting toilet that could provide an environmentally-friendly and inexpensive solution to the city’s public defecation problem.
3. Wanted in Maryland: “Poop power”
Looking to meet its alternative energy goals and reduce fertilizer runoff into the Chesapeake Bay, Maryland’s state government sought proposals to purchase electricity generated from animal waste like poultry litter and livestock manure.
4. Final space mission recycles urine into drinking water
NASA’s final space shuttle mission was big news this year, but the astronauts onboard the Atlantis also carried out an interesting recycling experiment: converting urine into drinkable water with no power source.
Astronauts at the International Space Station have been drinking from a machine that recycles urine into water for several years, but the machine consumes too much of the lab’s limited energy supply. To solve this problem, astronauts on the final space mission planned to test a recycling kit that uses forward osmosis, rather than a power source, to purify urine.
5. Dog poop power in Phoenix suburb
The Phoenix suburb of Gilbert considered converting dog waste from a popular dog park into methane to power the park’s street lamp this year. The town is seeking a corporate sponsor for the $25,000 project, and Arizona State University science students would be charged with designing the digester.
6. Recycling diapers into green building materials
Can you build a house out of dirty diapers? Canadian recycling company Knowaste announced plans to open five facilities in the U.K. to take the wood pulp and plastic from used diapers and feminine hygiene products and turn them into building materials like roofing shingles and synthetic wood. The organic waste from the absorbent hygiene products will be dried and gasified to create energy.
7. San Antonio River Walk’s dirty secret
With the Lone Star State in the midst of a historic drought, San Antonio has found a way to keep its popular downtown river flowing in the dry summer months: treating the city’s sewage water to near-drinkable quality and pumping it into the body of water.
The local Toyota manufacturing plant, Microsoft data center and golf courses also use the recycled water, and the water department says the sewage treatment program is saving a billion gallons of water a year.
8. Cincinnati Zoo composts its animal waste
Rather than send another 1 million pounds of animal waste to the landfill this year, the Cincinnati Zoo decided to start composting the excrement and will apply the resulting nutritious fertilizer on the zoo’s gardens.
9. Saving lives with a composting toilet
Duke University environmental engineer Marc Deshusses is developing a simple waste disposal system specifically designed for developing countries, where a lack of sanitation allows diseases like hepatitis, dysentery, typhoid and cholera to spread.
The composting toilet system will be simple enough that a single family can construct it in one day, using everyday materials for less than $100. Rather than release the methane the waste emits into the atmosphere, the system captures and burns the gas to kill the bacteria and viruses in the waste.
In November, the Bill and Melinda Gates Foundation awarded Deshusses with a $100,000 grant to complete the project.
10. Huggies sponsors diaper composting abroad
In 2009, Kimberly-Clark, maker of Huggies-brand diapers, worked with New Zealand company Envirocomp to establish the country’s first commercial diaper composting facility, which mixed diapers with local green waste to create a compost product suitable for commercial gardening and landscaping.
This year, the manufacturer of health and hygiene products announced that it signed a sponsorship agreement with Envirocomp’s parent company that plans to build diaper composting facilities in the United Kingdom, Ireland, Australia and mainland Europe in 2012.
But when will diaper composting come to the U.S.? Kimberly-Clark told Earth911 that it wants to develop similar initiatives in the U.S. and is currently searching for partners with the best solutions.