Grantee Research Project Results

Final Report: Electrochemical Treatment and Recycling of Spent Perchlorate-Contaminated Ion-Exchange Regeneration Brine

EPA Contract Number: EPD08029
Title: Electrochemical Treatment and Recycling of Spent Perchlorate-Contaminated Ion-Exchange Regeneration Brine
Investigators: Stotter, Jason M.
Small Business: Eltron Research & Development Inc.
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2008 through August 31, 2008
Project Amount: $70,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2008) RFA Text |  Recipients Lists
Research Category: SBIR - Water and Wastewater , Small Business Innovation Research (SBIR)

Description:

The goal of this Phase I program was to demonstrate feasibility for the use of electrocatalytic reduction of perchlorate to destroy perchlorate in ion-exchange regeneration brines. Electrodes of a type not previously applied to this problem were fabricated and tested at the bench scale (10 mL sample volumes) for effectiveness at reducing perchlorate. Several catalyst materials and experimental conditions were tested. The best performing material was used in a larger flow cell (1 L sample volumes) to demonstrate feasibility of up-scaling to an online process.

Summary/Accomplishments (Outputs/Outcomes):

During the Phase I program, sodium perchlorate and perchloric acid solutions of concentrations in the 100 mM range were treated electrochemically to reduce perchlorate. Sn-based catalysts were found to be effective but were not dimensionally or chemically stable. Ti-based catalysts were found to be ineffective. Pt-based catalysts were found to be effective and stable and thus were used in the flow cell. Both Sn- and Pt-based catalysts were found to be effective at solution pH of 2 or lower. At the bench scale, the performance of the best performing catalyst material was comparable to that reported in the literature (ca. 5% decrease in concentration). In the flow cell, the performance of this catalyst sometimes exceeded the performance reported in literature, but reproducibility was lower.

Conclusions:

Electrocatalytic destruction of perchlorate in a flow cell may be an effective strategy to treat spent perchlorate ion-exchange regeneration brines. An electrocatalytic electrode can be fabricated that allows a decrease in perchlorate concentration in low pH solutions with application of electrical current.

Supplemental Keywords:

small business, SBIR, EPA, drinking water, water monitoring, perchlorate, electrolytic water treatment system, polymer membrane electrode, drinking water source, well, resin disposal, brine disposal, ion-exchange, cathode, electrolytic system, perchlorate treatment, bioreactors, granular activated carbon systems, water, scientific discipline, RFA, environmental chemistry, drinking water contaminants, remediation, drinking water treatment, ion exchange perchlorate, treatment, destruction, ion-exchange brine,, RFA, Scientific Discipline, Water, Environmental Chemistry, Drinking Water, ion exchange, electrochemical reduction, remediation, drinking water contaminants, drinking water treatment