The objective of this study was to identify operation conditions for the MIEX® process to
achieve the following simulated distribution (SDS) disinfection byproducts (DBP) goals: 60 µg/L
of total trihalomethanes (TTHMs) and 45 µg/L of haloacetic acids (total of five species, HAA5).
Bromide and natural organic matter (NOM) were targeted as the major DBP precursors to
remove. Concentrations of bromide and total organic carbon (TOC) tested at the Palmdale
Water District Water Treatment Plant, California (PWTP) averaged 190 µg/L and 4.0 mg/L,
respectively. Contact time had no impact on TOC or bromide removal performance within the
range tested (7.5 to 25 minutes) for the resin concentrations considered (20 to 30 ml/L).
Conversely, increasing regeneration rate (RR) improved process performance, specially
bromide removal. TOC and UV absorbance at 254 nm (UV-254) removal increased
approximately 8 percent over the tested equivalent fresh resin dose (EFRD) range (i.e., 0,9 to 6
mL/L), while bromide removal consistently increased, from 5 to 40 percent, with increasing input
of fresh resin. Sulfate removal increased sharply when EFRD was increased from 1.6 to 2.9
mL/L, after which its removal stabilized at 80 percent. Sulfate competes for the same ion
exchange sites that bromide and organic matter, and its presence may have been a detriment to
the removal of these parameters.
The removal goal for HAA5 was achieved with treatment with MIEX® resin operated at a 5%
RR and 7.5 minutes contact time. The TTHM goal was only reached with MIEX® treatment
(resin concentration of 25 mL/L) followed by coagulation, using the following combination of RR
and ferric chloride doses: 5% RR and 50 mg/L of ferric chloride; and, 15% RR and 28 mg/L
of ferric chloride. Includes 6 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.2 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 15 |
| Published : | 06/17/2005 |
