AWWA ACE63080

This research examined the removal of perchlorate from drinking and groundwater with an innovative method using titanium metal as a chemical reductant. The zero valent titanium was induced by pitting corrosion to remove the surface oxide film by applying electrochemical potential. Localized breakdown of the surface oxide film by the pitting corrosion exposed the underlying bare titanium and perchlorate was reduced to innocuous chloride by the bare titanium. The rate of perchlorate reduction was highly dependent on the applied current. One-half of reaction time to reduce 1 mM of perchlorate was 1.5 hrs when 200 mA of constant current was supplied during the reaction. Mass balances revealed that oxidation was also developed on the surface oxide film, where the pitting corrosion did not exist. The titanium system effectively destroyed both mg/L and µg/L levels of perchlorate and achieved below 24.5 µg/L of the DWEL. Includes 15 references, table, figures.