New Process for Perchlorate Reduction in Drinking Water Treatment Units

Perchlorate contamination of groundwater and drinking water supplies is emerging as a major problem because it causes irreversible brain damage and other health effects, especially in the fetus and young children. Present perchlorate treatment is expensive and creates a secondary brine, with high levels of nitrate and perchlorate for its users to manage. This Phase I SBIR project is expected to provide a low-cost solution with no secondary residuals for customers to manage. Our new perchlorate reduction technology is based on a chemically impregnated granular activated carbon (GAC). The manufacturing process is designed to provide the maximized amount, position, and species of active reagent in GAC to solve different clients’ perchlorate problem(s). In addition to solving the perchlorate problem in drinking water treatment units (DWTU) at the point of use (POU) scale, it has applications in municipal and military installations applying GAC for pump-and-treat adsorption of trace organics in addition to perchlorate at 20,000-40,000 pound adsorbent used. This project involves novel concepts for the application of iron-based chemistry for pollution control applications. Smart composite materials and performance tests in this project offer a wide array of perchlorate and other simultaneous environmental problem-solving applications. The principal investigator has a proprietary laboratory capability called the Gravimetric Rapid Pore Distribution (GRPD) method, which provides information about the adsorption energy distribution of sites in heterogeneous adsorbents like GAC. The GRPD method provides valuable information to sorbent manufacturers and users not obtainable by any other present method. The chemical impregnant will be added at four concentrations and two distinctive forms, organic and inorganic. Perchlorate reduction will be evaluated with spiked drinking water using classical isotherms and mini-columns. Mini-columns provide the treatment performance: number of bed volumes and shape of the mass transfer zone. PACS’ best new sorbent will be evaluated in a modified (sorbent replacement) DWTU from a major POU pour-through pitcher manufacturer. PACS will apply its proprietary GRPD technology to validate the positional placement of the impregnants into GAC. PACS’ goal is placement onto the transport pores and none of the GAC adsorption pores. PACS’ new GAC product offers simultaneous trace organic removal (no loss of capacity in starting GAC) and inhibition of the GAC pH rise phenomenon, when it is first used in water application, in addition to perchlorate reduction. There are many targeted customers for this technology and many more will be available after the U.S. Environmental Protection Agency and states set the maximum contaminant level for drinking water.