Background
In smaller rural communities, producing potable water often does not involve the highly centralized treatment and distribution infrastructure seen in larger cities. Instead, smaller point-of-use or point-of-entry water treatment solutions provide more cost-effective approaches. With ever-tightening water quality regulations, more focused research has been devoted to discovering ways to purify water inexpensively on a small scale. The leading edge of this research revolves around nanotechnological solutions that exploit various properties of hybridized materials to remove water contaminants.
The fabrication of nano-enabled hybrid sorbent media typically includes precipitation of nanomaterials within the pores of a base support material, such as hybrid ion exchange (HIX) resin, granular activated carbon (GAC), or powder activated carbon (PAC). Precipitating nanosized iron (hydr)oxide within HIX, for instance, forms a media that can remove arsenic and organic pollutants. Similar to iron (hydr)oxide for arsenic removal, hydroxyapatite (HAP) has been shown to be suitable for fluoride removal. Thus far however, nano-enabled HAP hybrid sorbents have been unable to (1) remove contaminants apart from fluoride, (2) operate in continuous-flow systems, and (3) be fabricated at room temperature.
Invention Description
Researchers at Arizona State University have developed a new process for synthesizing nano-enabled HAP hybrid sorbents that directly addresses the above shortcomings. The simple, inexpensive process can be performed at room temperature. Even in continuous-flow systems, the fabricated HIX-HAP sorbent media simultaneously removes fluoride and other contaminants such as nitrate from complex water matrices. Not only is this unachievable with virgin ion-exchange media, but the fluoride sorption capacity of the HIX-HAP media exceeds that of activated alumina (AA), considered to be the best available fluoride removal technology.
Potential Applications
• Water treatment
• Sorbent media fabrication
Benefits and Advantages
• Superior – Fabricated HIX-HAP media exceeds AA in fluoride removal capability
• Non-restrictive – HIX-HAP media is effective in both continuous flow or batch treatments, and requires neither water pH adjustments nor membrane separation
• Broad-spectrum – HIX-HAP media removes both nitrates and fluoride
• Biocompatible – Leaching of HAP is not harmful to human health
• Energy-efficient – Media fabrication is performed at room temperature unlike most alternatives
• Adaptable – Fabrication process can be applied to a variety of base porous supports, particularly those that are temperature-sensitive