AWWA ACE58104

Assessment on the feasibility of bromate reduction by zero-valent iron (Fe0)has been carried out in this study. The effects of iron types, iron surfaceconcentrations, mixing rates, pH, and concentrations of dissolved oxygen(DO), natural organic matter (NOM), nitrate and nitrite were investigated withbatch tests. The observed rate constant (kobs) and the surface-area-normalizedrate constants (kSA) were obtained from pseudo-first-orderkinetics. The data revealed that irons from different manufacturersdemonstrated significant variations in bromate reduction. Monotonic increasesin the kobs were observed with increases in the iron surface concentration andthe mixing rate. The kobs were also found to increase with a decrease in pH,especially when solution pH decreased from 6 to 5.5. The effects of DO,NOM, nitrate and nitrite on bromate reduction were insignificant, presumablydue to the excessive Fe0 concentrations. Preferential reduction of bromatemight also contribute to the effective bromate removal when nitrate or nitritewas present. Under the experimental conditions, soluble iron (Fe2+/Fe3+) atconcentrations of sub to a few mg/L (up to 6 mg/L) were observed only in thebeginning of all test runs. These findings indicate that chemical reduction byFe0 can be a very effective alternative when bromate removal is required. Includes 24 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/15/2003

Number of Pages:

10

File Size:

1 file , 320 KB