It turns out that one man’s excrement might be another man’s treasure, as a team of Stanford scientists may have discovered a technique to transform very hazardous sewage treatment by-products into valuable materials for agriculture and even electronics. The researchers think it has the potential to enable for significantly more effective water reuse – something that is badly required in many areas where clean water is scarce – while also transforming a poisonous waste product into one with key applications in a variety of sectors.
In a statement, senior author Will Tarpeh, an assistant professor of chemical engineering at Stanford University, stated, “We are continually searching for methods to shut the loop on chemical manufacturing processes.” “The effective conversion of sulfur pollution into goods like fertilizer and battery components is a critical elemental cycle with opportunity for improvement.”
Their findings were published in the ACS ES&T Engineering journal. One technology has been identified as a strong candidate as scientists strive to develop cost-effective treatment methods for the massive volume of sewage individuals produce: anaerobic filtration.
This method includes circulating wastewater through an active biomass filter, which captures and destroys solids and undesirable particles in the water. It is good for removing particles from wastewater and even water that has already been treated, and it requires no energy. Anaerobic filtration, like many good things, has a drawback: it creates a significant amount of sulfide. Sulfide is poisonous, and dealing with significant amounts of it is quite challenging. Current by-product management approaches create more hazardous compounds, which damage pipelines and make further water disinfection harder.
Researchers questioned how to convert the sulfides into anything practical in the search for a better alternative. Sulfur-containing fertilizers, for example, are commonly utilized by farmers since sulfur is a key component for plants. However, converting these waste products into fertilizer is a process that has yet to be perfected. The researchers began converting wastewater sulfides into valuable chemicals using electrochemical sulfur oxidation and studied the process with microscopy to discover where the reaction was restricted, as well as any obstructions that may prevent sulfur recovery.
They refined the technique to the point where it could be powered by renewable energy and utilized at scale to cure large cities. It might potentially create ammonium sulfate fertilizer directly if used in conjunction with other nitrogen recovery techniques. The team now intends to improve the method and use it as a strategy to minimize the hazardous output of wastewater, reduce pollution, and utilise the by-products in a beneficial way. In a statement, main author Xiaohan Shao, a student in civil and environmental engineering at Stanford, stated, “Hopefully, our work will assist expedite the adoption of technology that mitigates pollution, recovers valuable resources, and provides drinkable water all at the same time.”