the energy in wastewater treatment most commonly comes from carbon containing organic matter. bacteria convert organic matter into methane, a combustible fuel that can be burned to generate power. in addition to carbon containing organic matter, there is also nitrogen in wastewater. unfortunately, current treatment processes don’t recover energy from waste nitrogen. but what if we could convert waste nitrogen into a combustible gas, just like converting organic matter into methane? it turns out we can! that’s where the rockets come in. bacteria are capable of converting waste nitrogen into nitrous oxide… yeah, nitrous oxide. the same stuff your dentist gives you, although dentists usually call it “laughing gas”. it’s also the same gas racecar enthusiasts use to supercharge their engines, although they call it “nitrox”. it’s also the same gas that has been used for decades in rockets. in fact, space ship one, the first privately manned spaceplane that is paving the way for sub-orbital space flights open to the public, used nitrous oxide in its rocket motors. it’s powerful stuff and we can get it for free from wastewater! at stanford we are developing a way to get bacteria to convert waste nitrogen into nitrous oxide, thus enabling energy recovery from both waste carbon and nitrogen. by producing nitrous oxide, we could essentially “supercharge” wastewater treatment, kind of like a nitrox turbocharged racecar.

wastewater treatment may not take us to the moon, but it can provide a serious amount of free and clean energy. considering that the treatment of wastewater consumes 3% of u.s. energy supply and wastewater treatment plants are often the highest energy expenditure for cities, generating power from wastes seems like a really good idea.

throughout his project, pregitzer has made efforts to increase the involvement of teachers and students in science. every summer, the weeklong teacher institute brings teachers to the field sites and laboratories connected to pregitzer’s project. there, teachers learn about the impact of elevated carbon dioxide and ozone levels, nitrogen saturation, acid rain, and invasive species on forest ecosystems while earning graduate course credit. by the end of this intensive week, each teacher develops a “citizen science” project that he or she can use in the classroom.

the teacher institute multiplies the impact of the instruction by providing teachers with educational tools they can use in the classroom and equips the teachers with the knowledge and confidence to seek out further research opportunities between their classes and professional scientists. for instance, one teacher used her experience at the course to develop a collaborative project with a government agency to test acid deposition around a local power plant. pregitzer’s course has received national attention—both the u.s. forest service and the national park service are looking at ways to develop programs similar to the global climate change teacher institute around the country.