AWWA ACE63010

Arsenic contamination in groundwater is of major concern to many water treatment facilities in the world. It is generally known that As(III) is more toxic than As(V) and organic forms of arsenic. Various treatment technologies have been applied to remove arsenic from drinking water such as coagulation-precipitation, reverse osmosis, ion exchange, and adsorption-filtration. Adsorption processes are often considered to be the most effective forms of treatment for As(V), but they can be limited in their ability to remove As(III). To enhance removal efficiency of adsorption process for As(III), this study has focused on developing highly ordered mesoporous adsorbents (HOMAs). One approach for fabricating reactive sites for As(III) in HOMAs is to incorporate nanoscaled titania (TiO₂) into a mesoporous silicate molecular sieve such as SBA-15. Another approach is to fabricate O-Ti-O sites by producing mesoporous titania (MT). Kinetic tests at different initial pH (4, 7, 9.5) were conducted with As(III) to evaluate rates of adsorption and ultimate sorption capacity of two HOMAs. Greater extents of adsorption were observed at higher pH for mesoporous titania, but silicate molecular sieve with incorporated titania showed the most removal of As(III) at the intermediate pH (pH 7). Includes 10 references, figures.