Sustainable You at the Zoo

by Mark Edwards

any animals, plants and entire ecosystems are threatened with extinction due to global climate change, food costs, freshwater scarcity and the availability of fossil fuels and fossil nutrients (i.e. fertilizers). ZooPoo addresses each of these challenges and shows visitors how to change their own behaviors to save animals, plants and ecosystems as they enhance our communities. “Sustainable You at the Zoo” will provide a take-home checklist to support eco-smart lifestyles.

ZooPoo will show energy and nutrient recovery, recycle and reuse demonstration and learning facilities that enable guests of all ages to see, experience and learn how to adopt green behaviors and lifestyles.

ZooPoo uses the zoo waste stream and recovers and reuses energy and nutrients to produce electricity, freshwater, vitamins, minerals, health foods, animal feed, fertilizers and medicines for zoo animals and plants. Algae recover the hydrocarbons stored in ZooPoo, which can then be used for energy rather than burning fossil fuels. The facility will also include demonstrations of other renewable forms of energy such as solar, wind and possibly geothermal systems.

Elephants are among the smartest animals at the zoo. They may serve as the ZooPoo icon because each adult elephant contributes more than 300 pounds a day to the ZooPoo pile.

Elephants have the most inefficient digestive systems, at 40% of their intake, even though they have 19 meters, (21 yards) of intestine.

ZooPoo will demonstrate how to transform ZooPoo from waste to valuable bioproducts that benefit plants, animals and people.

Mother Nature has been cycling nutrients successfully with algae for 3.5 billion years. ZooPoo builds on nature’s first and most efficient food and energy production system. Many people are unaware of the potential for algae to provide carbon neutral food, feed and fuel. The few algae producers have worked under the public radar, distant from population centers. ZooPoo raises algae farming to a new level by enabling algae production and its many coproducts from the zoo’s waste stream. After constructing the demonstration, production, and education centers, ZooPoo will be self-sustaining environmentally and economically.

Algae production (right), creates biomass with surplus inputs that are cheap and will not run out – sunshine, CO₂ and wastewater nutrients. Algae production systems get most of their needed energy free, from sunshine, but require some additional energy for mixing and extraction.

The energy stored on earth comes from the sun. Nature transformed the algae biomass from ancient oceans into fossil fuels, but the process took tremendous pressure and heat over 400 million years. Fossil fuels offer a convenient form of concentrated energy, but pollutes the atmosphere with heat-trapping gases, as well as heavy metals and black soot particulates. Algae produce biofuel in weeks rather than eons.

Algae biofuels displace the use of fossil fuels gallon-for-gallon. Unlike fossil fuels, during production, algae release only pure oxygen to the atmosphere. Algae oil creates clean, renewable biofuels that burn with no black soot particulates because the algal oil has not fossilized. The ZooPoo facility will have a small motor running on algae oil. Guests can attest that the simple vegetable oil burns cleanly but has a bit of an odor similar to French fries.

After recovery of algae oil for energy, other coproducts may be extracted from the remaining biomass or processed into renewable natural gas or transportation fuels. Solid wastes are remediated through anaerobic digestion that provides both gasses and waste water, that provide more algae feedstock.

Anaerobic digesters (above), use a series of biological tools and apply micro-organisms (anaerobes) to break down biodegradable material in the absence of oxygen. An end product, biogas, may be combusted to generate electricity. Flue gas from combustion can feed more algae.

The water used to culture the algae may come from any source, but high-nutrient wastewater offers many advantages, especially free nutrients. Water may be recycled and the residual nutrients reused up to 10 times. Lipids may be pressed out of the biomass for use as healthy oils for animal feed or converted to liquid transportation fuel. Algae protein provides food energy for animals, fowl and fish. The remaining carbohydrates can be refined into energy, biodegradable bioplastics, paper, fabrics, green chemicals and many other bioproducts. Algae can also provide vitamins, medicines and vaccines for the zoo animals.

The ZooPoo exhibit’s purpose is simple: show rather than tell visitors how to recover, recycle and reuse nutrients from zoo animals and botanical wastes. The message also includes how to practice abundance methods that use no or minimal fossil resources.