Final Report: Removal of Arsenic From Drinking Water Using a Novel Hybrid SorbentEPA Contract Number: 68D02098
Title: Removal of Arsenic From Drinking Water Using a Novel Hybrid Sorbent
Investigators: Saha, Anuj K.
Small Business: VEETech PC
EPA Contact: Manager, SBIR Program
Project Period: October 1, 2002 through July 31, 2003
Project Amount: $99,852
RFA: Small Business Innovation Research (SBIR) - Phase I (2002) RFA Text | Recipients Lists
Research Category: Water and Watersheds , SBIR - Water and Wastewater , Small Business Innovation Research (SBIR)
VEETech, in collaboration with Lehigh University, developed and tested polymeric-inorganic hybrid sorbents, or HIXs, for the removal of arsenic from drinking water. The broad objectives of the Phase I research project were to synthesize, test, and demonstrate a new hybrid polymeric-inorganic sorbent that offers the following characteristics for the removal of arsenic from drinking water:
· Is superior to other fixed-bed column sorbents, with excellent mechanical strength and attrition-resistance properties.
· Is selective towards both forms of arsenic species (III & V).
· Does not warrant any pre- or posttreatment, such as pH adjustment or oxidation.
· Does not alter the electrolytic quality of the treated water.
· Does not require frequent in situ regeneration.
· Does not produce fines during column operation.
· Has the capacity to treat a large number (> 5,000) of bed volumes (BV) of water before any arsenic breakthrough.
The results of the project reveal that all broad objectives were met or exceeded. For example, the synthesized HIX media exhibited excellent mechanical strength and did not generate any attritional losses or fines during column runs. The HIX also exhibited excellent affinity and selectivity for both forms of arsenic species. In fact, the HIX treated higher BVs (13,000 versus 8,000) of arsenic III laden water than arsenic V when the two species were studied independently. The HIX also exhibited no reduction for arsenic removal efficiency, even in the presence of high-soluble silica and phosphate concentration. These results are quite remarkable, because most sorbents for arsenic removal currently available in the marketplace cannot accomplish similar results.
The Phase I column runs consistently demonstrated that the HIX does not require any pre- or post-treatment, nor does it require frequent regeneration. The column runs also revealed that HIX does not alter the electrolytic quality of the treated water. The pH and the total dissolved solids of the influent and the treated water essentially remained the same.
All of the three column tests performed during the Phase I research project demonstrated far greater than 5,000 BV throughput before breakthrough of arsenic contaminants. The two 11 mm diameter columns treated up to 8,000 BV (predominantly arsenic V, in the presence of soluble silica) and 13,000 BV (arsenic III) of water, and the 15 mm diameter column treated arsenic up to 10,000 BV before any breakthrough. The research project demonstrated that great promise exists for the HIX media to be a simple, adaptable, reliable, low-cost, and high-performance technology for the removal of arsenic from drinking water.
The following conclusions can be drawn from the project's results:
· The HIX is a mechanically/structurally sound sorbent with superior attrition resistance properties.
· It is selective for both forms (III & V) of arsenic species.
· It does not require any pre- or post-treatment.
· It does not alter the electrolytic quality of the treated water.
· It does not require frequent in situ regeneration.
· It does not generate fines.
· Soluble silica and phosphate does not affect the arsenic removal efficiency on HIX.
· The HIX can treat far greater than 5,000 BV of water before breakthrough.
Based on the results of Phase I, VEETech recommends the performance of pilot/full-scale tests at a small/medium-sized water utility with elevated levels of arsenic, and ascertainment of realistic capital and operational costs for full-scale treatment units.