It was already known that algae breaks down and feeds upon waterborne compounds such as phosphorous, nitrogen, carbon and heavy metals. Additionally, as algae absorbs nutrients and blocks sunlight in the water, it outcompetes microorganisms such as harmful bacteria, causing them to starve.
With these factors in mind, scientists from India's Shoolini University collected Pseudochlorella pringsheimii algae from a natural pond, then cultivated it in tanks of raw urban wastewater that contained heavy metal pollutants and antibiotic-resistant bacteria. After 14 days, it was found that the heavy metal levels had dropped drastically, and the bacteria were almost completely eliminated.