It's official. Your wastewater is now an extremely valuable resource
Water may be a fundamental human need; however, today, we live in a world where more than 785 million people lack access to even basic water services. This problem is expected to worsen as a result of human-caused climate change since disrupted weather patterns can lead to inconsistent water supply and contaminated water supplies.
Closing the gap between wastewater and drinking water with highly efficient methods could help. Now, a team of researchers from Stanford University has discovered how to optimize electrical processes for transforming sulfur waste, which could pave the way for economical, renewable energy-powered wastewater treatment that produces drinking water.
"One person’s wastewater is another person’s treasure"
Over the years, scientists have been researching novel approaches we can use to purify wastewater and reintroduce it into our water sources. One technique called anaerobic filtration has been leading the field since it requires little energy to purify a large amount of sewage water. However, there is a major flaw, as anaerobic filtration produces dangerous harmful byproducts called sulfides, which are exceedingly dangerous to our health and the environment, while cleaning up the water.
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The Stanford University researchers were able to tackle this problem by reframing the cost of anaerobic filtration as a hidden treasure. According to the study published in the journal ES&T Engineering, the researchers came up with a method for converting wastewater-based poisonous sulfides into harmless molecules, which can be highly important resources for agricultural and rechargeable technology.
How did they do it?
Instead of utilizing chemicals to separate sulfur derivatives into harmless components, which frequently corrodes purification system pipes, the researchers employed "electrochemical sulfur oxidation." This consumes little energy and allows for fine-tuned control of the final sulfur compounds, which eliminates the threatening chemical from anaerobic filtration altogether.
"The process I'm working on is to convert sulfides in wastewater electrochemically into something more valuable, for example sulfuric acid, which can be used in many manufacturing processes and also fertilizers," explained Xiaohan Shao, a Ph.D. student in civil and environmental engineering at Stanford University and lead author of the study, in a video about the study.
The researchers state that this technique uses so little energy that it could be powered entirely by renewable sources and applied to entire city sewage systems. Ultimately, this, integrated into other advanced wastewater treatment technologies, could shorten the gap between wastewater and drinking water one day, and pave the way for mining sewage for precious elements that could someday power smartphones and even airplanes.