CBEE seminar with Dr. Arup SenGupta (Lehigh University)

Zirconium, the 21st most abundant element in the world, is stable, chemically innocuous and non-hazardous. Nanoparticles of zirconium oxide (ZrO₂) have unique sorption properties to bind a variety of trace contaminants including arsenic, fluoride, phosphate and lead. We have developed a process to disperse ZrO₂ nanoparticles within the gel phase of an anion exchanger with quaternary ammonium functional group. The resulting hybrid ion exchanger, referred to as HIX-NanoZr, is a robust sorbent material that is also amenable to regeneration and reuse (1). Nearly 400 million people in Asia and Africa drink groundwater that contains toxic levels of fluoride and arsenic. Both HIX-NanoZr and HIX-NanoFe are now commercial materials and over one million people around the world drink arsenic- and fluoride-safe water through use of these sorbents.

Brackish water desalination plants are mostly located inland and must resort to expensive concentrate disposal methods like deep well injection or evaporation ponds. Increasing the recovery of RO process would obviously reduce the volume of concentrate to be disposed of but cannot be implemented due to scaling of sulfate (CaSO₄, BaSO₄, etc.) and silica (SiO₂) resulting in fouling of RO membranes. We have developed a hybrid Ion Exchange-Reverse Osmosis (HIX-RO) process where tunable anion exchange resins can eliminate sulfate precipitation (2) and silica fouling without addition of external regenerants or anti-scaling chemicals. Results from the field experiments will be presented.

References: