Abstract
To enhance removal of HAA precursors in water filtration processes, we produced metal oxide-coated filter media using quatz sand and anthracite coated by iron oxide and manganese oxide. The amounts of iron oxide coated on filter media were significantly greater than those of manganese oxide, and iron oxide coatings produced surfaces with smaller pores and larger specific surface areas. Anthracite attached more metal oxide coating than quartz sand, which offers an advantage for adsorption of HAA precursors. In column filtration experiments, iron oxide-coated sand demonstrated high removal rates of DOC (50 - 70%) and HAAFP (63 - 70%), whereas the removal rates by manganese oxid-coated filter media were low. These results suggested that iron oxide-coated anthracite is the most suitable filter media for removal of HAAFP among the four filter media tested in this study.
It was also found that the amounts of HAAFP removal were correlated with the amounts of the metal oxides retained in the columns; thus, by increasing the amounts of metal oxide in columns, we can further increase the removal rates of HAAFP.
