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| Use of Ozonation in Combination with Nanocrystalline Ceramic Membranes for Controlling Disinfection By-products |
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| Principal
Investigators: |
Susan
Masten, Department of Civil and Environmental Engineering; Melissa
Jane Baumann, Department of Chemical Engineering and Materials
Science; Simon Davies, Department of Civil and Environmental
Engineering |
| Research
Assistants: |
Bhavana
Karnik, Nikhil Theyyuni |
| Sponsor:
|
Environmental
Protection Agency |
Abstract
The objective of this study is to determine the feasibility of using
a combined ozonation and membrane filtration system to control disinfection
by-products (DBPs) precursors in drinking water treatment process. Conventional
ceramic membranes and ceramic membranes coated with a nano-crystalline
catalyst that decomposes ozone are being used in this study. The particular
objectives are:
- To develop methods for the preparation of a nano-crystalline ceramic
membranes which catalyze the decomposition of ozone and foulants and
to characterize these membranes.
- To determine the effect of ozonation on membrane fouling in filtration
systems using both conventional and catalytic membranes.
- For the source waters studied, determine the effect of ozonation
on the properties of natural organic matter and relate this information
to the overall performance of the system.
- To investigate the effect of control parameters on the fouling rate
and product water quality using selected conventional and catalytic
membranes.
The fouling experiments indicate that, in the absence of ozonation,
a decline in permeate flux over time occurs. The injection of ozone
just prior to filtration results in a recovery of the flux to about
85% to 90% of the initial flux. The effects of ozonation resulted in
the degradation of NOM and caused changes in the NOM structure, which
reduced the reactivity of the percursors of disinfection by-products
towards ozone. With an ozone concentration of 1.5 g/m3 and a 1 kD membrane,
water from Lake Lansing, a borderline eutrophic lake with a TOC ranging
from 8-12 mg/L, was treated to meet water-quality requirements of the
Stage 2 D/DBPs Rule.
We expect to develop and demonstrate that treatment using catalytic
nano-crystalline ceramic membranes in combination with ozonation is
more effective than conventional methods, including ozonation, and
other membrane processes in terms of operational performance and removal
of DBPs.
Resulting Publications / Presentations
- Karnik BS, Chen KC, Jaglowski DR, Davies SH, Baumann MJ, Masten SJ. Combined
Ozonation-Nanofiltration for Drinking Water Treatment. Presented at
the 78th American Chemical Society Colloid and Surface Science Symposium,
Yale University, New Haven, CT, June 20-23, 2004.
- Karnik BS, Chen KC, Jaglowski DR, Davies SH, Baumann MJ, Masten SJ. Effect
of combined ozonation-nanofiltration on water quality. Presented at
the 228th American Chemical Society National Meeting - Oxidation and
Reduction Technologies for Water Treatment, Philadelphia, PA, August
22-26, 2004.
- Karnik BS, Davies SH, Chen KC, Jaglowski DR, Baumann MJ, Masten SJ. Effects
of ozonation on the permeate flux of nanocrystalline ceramic membranes.
Water Research 39, pp 728-734, 2005.
- Karnik BS, Davies SH, Baumann MJ, Masten SJ. The effects of combined ozonation
and filtration on disinfection byproduct formation. Water Research
39, pp. 2839-2850, 2005.
- Karnik BS, Davies SH, Baumann MJ, Masten SJ. Fabrication of catalytic membranes
for the treatment of drinking water using combined ozonation and ultrafiltration.
Submitted to Environmental Science and Technology, 2005.
Future Work
- Investigate other membrane materials that may be better catalysts of ozone decomposition
- Improved understanding of the effects of operational conditions (e.g. ozone
dosage, TMP) on performance
- Studies using models foulants, e.g., polysaccharides, silica, humic materials
- Investigate the fate of other DBPs, e.g., bromate
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