The world produces much of poop, and we don’t always know what to do with it. In the past, governments have traditionally treated wastewater by removing and disinfecting pollutants before dumping a large portion of the by-products known as biosolids in dumps or landfills.
The USA produces more than 7 million tons of biosolids annually almost a third land in landfills. Global, around 30 percent the biosolids arrive in stockpiles and landfills every year.
However, the alternative disposal methods for Biosolid, once touted as environmentally friendly, have fallen out of favor. While About half of the US biosolids are there applied Significant research has recently been identified for agricultural purposes such as providing nutrients to crops and combating soil erosion Health risks associated with these techniques. After the treatment process they still can contain Hundreds of unregulated pollutants like hormones, pesticides, and drugs Per- and polyfluoroalkyl substances (PFAS), also known as “chemicals forever” because they cannot be broken down.
These findings have driven US cities to do so Ban Biosolids from farmland. Some countries like that Netherlands and Switzerland, have nixed their use in agriculture.
Companies like HJ Heinz and Del Monte have followed fit for the past decade they have claimed they will stop buying crops grown with biosolids.
Landfills are also increasingly rejecting the ingestion of biosolids as contents like PFAS become a major hazard in the long run and are very difficult to treat, says Marc A. Deshusses, a professor of civil and environmental engineering at Duke University who deals with waste -Energy processes deals with sanitary engineering. “We are in a situation in which there are fewer and fewer sales opportunities for biosolids in industrialized countries like the USA,” he says.
With piles of feces (and other sewage wastes) putting our food and water supplies at risk, scientists are working on safer and more sustainable alternatives. Here are some suggestions to help us deal with excess number two:
Building material
The construction industry notoriously consumed large amounts of energy and water while contributing almost 40 percent of global energy-related carbon dioxide emissions. Annual brick production requires More than 3.4 billion cubic meters of clay soil – comparable to over 1,000 soccer fields that were dug almost 500 meters deep. Putting biosolids in bricks, meanwhile, could reduce the massive amounts of virgin soil required each year.
In 2019 engineers at the Royal Melbourne Institute of Technology, Australia tested stones It consists of up to 25 percent biosolids and has found that these hybrids cut energy consumption by almost half during the burning process. They also found that heavy metals are unlikely to leak into the finished bricks. Still, the researchers recommended an in-depth chemical analysis before using it on a large scale.
natural gas
Wastewater can produce “biogas” when bacteria break down organic materials in an oxygen-free environment, a process that is already standard in sewage treatment plants. Only around 1 percent of US crops exploit their resulting biogas, which can be used to generate heat and electricity.
Some governments, including Germany and Italy, are now heavily subsidizing this practice. Europe’s biogas production from industrial and urban sewage sludge increased by 40 percent between 2017 and 2013. Meanwhile, countries in Asia, including China, Pakistan and Bangladesh, has developed Extensive biogas systems for home cooking.
Its greater potential: biogas obtained from wastewater can be converted into renewable natural gas and pumped into pipelines or used to power vehicles currently serving a tiny fraction of the demand. However, the global push towards renewable energies could make the practice more lucrative, according to Deshusses. From 2018 Europe led the world both in the generation of electricity from biogas and in the production of natural gas.
“Natural gas is extremely cheap, but it is fossil-based,” he says. “The same chemical formula and molecule, if it comes from renewable sources like biosolids or organic waste, earns a premium.”
However, the environmental impact is complicated. While it’s helpful as a renewable energy source, health and climate advocates have it criticized biogas as a whole, because when burned it creates the same pollutants as fossil fuel gas. However, this conversion prevents the more serious methane emissions that occur when the waste breaks down on its own.
And when upgrading to natural gas can improve air quality and reduce greenhouse gas emissionsIt is critical to limit the amount of potentially harmful by-products like methane can escape during production and distribution.
As for the biogas itself, researchers have stressed the importance of thorough cleaning systems and found that on its own it is still not an ideal solution to tackling global emissions.
Electricity and yes, drinking water
That’s right: our wastewater can ultimately lead to a clean drink. In fact, you can watch a video by Bill Gates drinking a refreshing cup of water from the poop. However, this is nothing new: Singapore has been for almost two decades has injected treated wastewater (also called NEWater) in its reservoirs. There it mixes with Rainwater and receives further treatment before you reach the residents’ taps.
The US also has a history of getting creative with flushed materials. California’s Orange County, for example has produced Drinking water from sewage since the 1970s. From 2018 it operated the world’s largest wastewater and drinking water plant. This year the system broke a world record by converting more than 100 million gallons of wastewater into drinking water.
In recent years, scientists have developed easily transportable, neighborhood-oriented machines that can produce safe drinking water from wastewater without the need for massive operations. Deshusses developed one together with his Duke colleagues Supercritical Water Oxidation Reactor (SCWO) that he Calls a “pressure cooker on steroids.”
The SCWO unit, which fits in a shipping crate, reaches more than 700 degrees Fahrenheit and pressure 240 times the atmosphere to burn organic matter quickly (without the typical gas emissions that come with combustion). In a matter of seconds, it produces clean water, electricity, and mineral nutrients that can be used as fertilizer.
This type of technology has been around for decades to treat industrial waste, but it had to be expanded for this specific purpose, he says. After receiving financial support from the Gates Foundation, his team began building a prototype on the Duke campus in 2013 and eventually founded 374Water.
Deshusses sees potential in its SWCO technology for vertical farming and broader use Circular economy. Currently, their models can produce up to 23,000 gallons of distilled water per day. It is currently being adapted for larger commercial units and 374Water plans to bring these to communities in the US and abroad in the future.
City governments are realizing that they would benefit from treating waste on site rather than transporting it Hundreds of miles away, Says Deshusses. The health consequences of the exported wastewater are indeed fell frequently on low-income black neighborhoods. Worldwide, technologies such as the SCWO reactor could help meet the challenges of sanitation and water scarcity.
The Gates Foundation also supported the Janicki Omni Processor from Sedron Technologies. The facility is about the size of a basketball court and dries and burns waste in minutes Generate electricity, heat, ash and water that are ready for the soil This is drinkable after further treatment (it can continuously provide drinking water for up to 100,000 people). As a result, the omni processor can run on its own juices and transfer the remaining power to nearby grids.
In 2015, Sedron sent the machine to Dakar, Senegal, where it was treated around 700 tons of faecal sludge in the first year of the pilot project. According to Sara VanTassel, mechanical engineer and president of Sedron Technologies, a local plumbing company is now planning to open more facilities across Senegal.
As with 374Water’s SCWO reactor, the Janicki Omni processor aims to eliminate the PFAS chemicals that often stay in drinking water – even after strict municipal treatment.
Thanks to the “intensive” conditions within the SCWO, such as the high temperature and the high pressure, stubborn chemical bonds can be broken through which PFAS remains attached. And when the omni processor burns waste, Sedron says it is exceeding the temperature required to destroy PFAS. Such burning does release certain pollutants depending on factors such as protein and caloric intake in the diet of the local population, although this is the case with the omni processor designed to mitigate them.
Even if it’s technically safe, what if someone feels uncomfortable sipping water that’s once filled with feces (and other gross substances like toilet paper)?
“There is no more water on the planet that fish, dinosaurs, cows or bears have not pooped on,” says VanTassel. “All the water droplets we drink in 2021 will be recycled. It’s just a matter of whether you believe this can happen quickly or over thousands of years. “
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