Without disinfectants or intensive use of energy

Israeli, US researchers develop filter membranes to make treated wastewater drinkable

Novel ultrafiltration membranes that significantly improve the removal of viruses from treated municipal wastewater used for drinking in water-scarce cities have been developed by researchers at Ben-Gurion University of the Negev in Beersheba and the University of Illinois at Urbana-Champaign.

Current membrane filtration methods require intensive energy to adequately remove pathogenic viruses without using chemicals such as chlorine, which can contaminate the water with disinfection byproducts. The scientists’ new approach for virus pathogen removal was just published in Water Research.

“This is an urgent matter of public safety,” the researchers agreed. “Insufficient removal of human Adenovirus in municipal wastewater, for example, has been detected as a contaminant in US drinking water sources, including the Great Lakes and worldwide.”

The norovirus, which can cause nausea, vomiting and diarrhea, is the most common cause of viral gastroenteritis in humans and is thought to be the second leading cause of gastroenteritis-associated mortality. Human adenoviruses can cause a wide range of illnesses that include the common cold, sore throat (pharyngitis), bronchitis, pneumonia, diarrhea, pink eye (conjunctivitis), fever, bladder inflammation or infection (cystitis), inflammation of the stomach and intestines (gastroenteritis) and neurological disease.

In the study, Prof. Moshe Herzberg of the department of desalination and water treatment in the Zuckerberg Institute for Water Research at BGU and his group grafted a special hydrogel coating onto a commercial ultrafiltration membrane. The “zwitterionic polymer hydrogel” repels the viruses from approaching and passing through the membrane. It contains both positive and negative charges and improves efficiency by weakening virus accumulation on the modified filter surface. The result was a significantly higher rate of removal of waterborne viruses, including human norovirus and adenovirus.

“Utilizing a simple graft-polymerization of commercialized membranes to make virus removal more comprehensive is a promising development for controlling filtration of pathogens in potable water reuse,” said Prof. Nguyen of the chemical engineering department at the Illinois university.