A team of environmental scientists from the Ben-Gurion University of Negev has created a circular procedure to eliminate the risk of effluent from phosphoric acid plants. The procedure recovers precious acids while transforming wastewater that is harmful to the environment into pure water. The primary component of industrial fertilizers, a huge global industry, is phosphoric acid.
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The American Chemical Society’s esteemed scientific publication ACS Sustainable Chemistry and Engineering has published its method. Lior Monat, a Ph.D. student in Dr. Oded Nir’s group, directed the study.
Phosphoric acid production generates a lot of industrial wastewater that cannot be treated efficiently because of its low pH and high precipitation potential.
Dr. Oded Nir, Study Co-Lead Researcher, Ben-Gurion University of the Negev
“Today, the wastewater is usually stored in evaporation ponds. However, these are prone to breaches, leakage, and flooding.”
Dr. Nir further added, “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. Nir concluded.
The scientists successfully tested the procedure in the lab using synthetic wastewater. The method effectively reduced the volume of wastewater by 90% while recovering clean water and phosphate. Additionally, it produced little to no mineral scaling, which could clog the membranes.
Furthermore, because the process required so little electricity, it appeared that the approach would be both technologically and economically practical.
“This process is very promising, and we encourage industry players to examine its potential and applicability at their factories,” says Dr. Roy Bernstein, co-lead researcher.
The research was supported by Israel Ministry of Science and Technology Grant 3-15505.
Monat, L., et al. (2022) Circular Process for Phosphoric Acid Plant Wastewater Facilitated by Selective Electrodialysis. ACS Sustainable Chemistry & Engineering. doi.org/10.1021/acssuschemeng.2c03132.