AWWA ACE70575

This powerpoint presentation begins by providing a brief overview of perchlorate and cationic surfactants. Hypotheses to test were: thiosulfate and other reduced sulfur species competes with perchlorate for adsorption sites on the tailored granular activated carbon (GAC); proportional diffusivity is not the appropriate similitude equation for surfactant tailored GAC; and, loading of surfactant to GAC plays a role in perchlorate adsorption. Topics covered include: reduced sulfur species; thiosulfate oxidation rate; and, effect of anions on perchlorate adsorption to TGAC. Conclusions indicated that: Thiosulfate affects the adsorption of perchlorate to Tailored GAC; proper prechlorination can markedly diminish the effects of thiosulfate; anions such as nitrate interfere with the adsorption of perchlorate to TGAC; and, oxidized forms of sulfur (SO₄ ^2-) do not affect the adsorption of perchlorates as much as thiosulfate. Includes table, figures.