During riverbank filtration (RBF), surface water is subjected to
ground passage and a combination of physical, chemical,
and biological processes (e.g., filtration, dilution, sorption,
and biodegradation) that can significantly improve the raw water
quality. This study of three drinking water utilities in the midwestern
United States compared RBF with bench-scale conventional
treatment for reduction of disinfection byproduct (DBP)
precursors. A companion article published in the October 2003
JOURNAL discussed the fate of DBP precursors and selected
microorganisms during RBF.
River waters from the three sites were subjected to a treatment
train consisting of coagulation, flocculation, sedimentation,
filtration, and ozonation. Data indicated that RBF performed as
well as or better than bench-scale conventional treatment with
respect to DBP precursor removal. Bench-scale treatment reduced
total and dissolved organic carbon concentrations by 20 to 50%,
whereas the water's subsurface travel to the closer wells at the
three sites resulted in reductions between 30 and 70%. Reductions
in precursor material for trihalomethanes, haloacetic acids,
haloacetonitriles, haloketones, chloral hydrate, and chloropicrin
were in the range of 40 to 80% with bench-scale treatment and
50 to 100% with RBF.
With respect to removal of natural organic matter and DBP
precursors, RBF has the potential to provide significant benefits,
comparable to those offered by conventional unit processes. As
RBF continues to gain popularity in the United States, one potential
major role for the process may be as a pretreatment step for
DBP precursor control. Includes 38 references, tables, figures.
| Edition : | Vol. 95 - No. 12 |
| File Size : | 1
file
, 730 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 14 |
| Published : | 12/01/2003 |
