The researchers Experiment using the same technique In the case of wastewater solids, it basically turns sludge into a solid product. “When you do pyrolysis, it kills these bacteria, pathogens and viruses because it’s thermochemical and it’s a heating process. It’s much cleaner,” says engineer Fengqi You. the study Cornell University Wastewater. Additionally, sludge is a heavy and difficult liquid to transport from the facility to the farm. “You transport a lot of water in it, but the density is low. But biochar is light, so you can put it in a bag and it’s easy to transport.” So producers can more easily transport it to distant farms. It can also be distributed more locally, such as to urban farms near wastewater sources.
Wastewater facilities can also produce fuel in anoxic chambers. There, microorganisms feed on the solid waste and release methane “biogas” as a byproduct. “This biogas can be burned to generate heat,” he says. In Ithaca, New York, the wastewater plant itself can be fully powered, but You is also experimenting with using biogas to heat nearby buildings, including a medical center. Heating buildings with natural gas increases carbon emissions into the atmosphere, but burning biogas comes from the crops we eat and the crops we grow that suck carbon from the atmosphere and drain into the sewer system. A carbon loop is formed.
Before producing biogas, these microorganisms also produce volatile fatty acids. Sybil Charbel, an environmental engineer who studies wastewater at Colorado State University, said they could be turned into jet fuel or even fuel for city vehicles. “There’s a lot of value in all kinds of volatile fatty acids,” says Charbel.
In addition to using solid waste as compost, as Epic Cleantech is experimenting with, urban farms can use recycled wastewater that has been disinfected but still contains nitrogen and phosphorus for use on crops. Charbel points out that there may be benefits to doing so. Although it is a plant, it is actually difficult to remove from the water. “If we can leave the nitrogen and phosphorus in the system, it’s a much more energy-efficient way to just utilize those nutrients directly,” Charbel says.
Overall, the straight waterways from water sources to cities to the ocean are beginning to curve. The future of wastewater is circular, recycled into drinking water, compost for urban farms, and energy. Drinking water from recycled toilets isn’t unnatural, it’s the kind of resourcefulness nature intended. “Recycling happens everywhere in nature,” says Kempes. “If there is an untapped energy source or nutrient, someone will find a way to use it. If we can make fertilizer, find a way to clean water, and at the same time generate heat and electricity, that means we It reflects the evolution of biology over billions of years.”
