Researchers Turn Industrial Wastewater Into Fertilizer

Researchers have developed a method of cleaning industrial wastewater and recovering valuable acids used for making fertilizers.

The team at the Ben-Gurion University of the Negev say they can eliminate the risks posed by phosphoric acid plant wastewater, and that their method is sustainable and economically viable.

Exposure to high quantities of phosphoric acid can cause a number of health effects, including vomiting, severe abdominal pains, and even death. 

The team evaluated the method with synthetic wastewater in the lab, with positive results. The process successfully recovered clean water and phosphates while reducing the volume of wastewater by 90 per cent.

Recovering phosphoric acid is beneficial as it is the main ingredient in industrial fertilizers. 

“Phosphoric acid production generates a lot of industrial wastewater that cannot be treated efficiently because of its low pH and high precipitation potential,” said Dr. Oded Nir, the co-lead researcher.

“Today, the wastewater is usually stored in evaporation ponds. However, these are prone to breaches, leakage, and flooding. Only a few years ago, an ecological disaster in Israel occurred when millions of cubic meters of this acidic wastewater were flushed down a creek. 

“Conventional treatment processes run into difficulties dealing with the acidity, salinity, and hardness of the wastewater. Therefore, we developed an alternative three-step process for the treatment of phosphoric acid wastewater comprised of selective electrodialysis, reverse osmosis, and neutralization.”

Dr. Roy Bernstein, co-lead researcher, said: “This process is very promising, and we encourage industry players to examine its potential and applicability at their factories.”

Their findings were published in ACS Sustainable Chemistry and Engineering, a journal published by the American Chemical Society.