Grantee Research Project Results
2003 Progress Report: Use of Ozonation in Combination with Nanocrystalline Ceramic Membranes for Controlling Disinfection By-products
EPA Grant Number: R830908Title: Use of Ozonation in Combination with Nanocrystalline Ceramic Membranes for Controlling Disinfection By-products
Investigators: Masten, Susan J. , Baumann, Melissa J.
Institution: Michigan State University
EPA Project Officer: Hahn, Intaek
Project Period: May 15, 2003 through May 14, 2006
Project Period Covered by this Report: May 15, 2003 through May 14, 2004
Project Amount: $353,959
RFA: Environmental Futures Research in Nanoscale Science Engineering and Technology (2002) RFA Text | Recipients Lists
Research Category: Nanotechnology , Safer Chemicals
Objective:
The objective of this study is to determine the feasibility of using a combined ozonation and membrane filtration system to control disinfection byproducts (DBPs) precursors in the drinking water treatment process. Conventional ceramic membranes and ceramic membranes coated with a nanocrystalline catalyst that decomposes ozone will be used in this study.
The initial goal of this project is the development of a nanocrystalline ceramic membrane that catalyzes the decomposition of ozone and has the desired porosity, permeability, and molecular weight cut-off (MWCO). Once a suitable membrane (or membranes) is (are) formed, we will evaluate the membrane(s) in combination with ozone for its ability to resist fouling, alter the natural organic matter (NOM) and control DBPs. The optimized membrane will be investigated to determine the effect of control parameters on the fouling rate and product water quality.
Progress Summary:
Titania membranes, with a MWCO of 15 kiloDaltons (kD), were used in an ozonation/membrane system that was fed with water from Lake Lansing, which had been prefiltered through a 0.45 μm glass fiber filter. The application of ozone gas prior to filtration resulted in significant decreases in membrane fouling. The effects of ozonation could not be explained by physical scouring of the filter cake. Decreases in the pH resulted in a concomitant increase in the dissolved ozone concentration in the feed water and in an improvement in permeate flux recovery. Increasing the ozone concentration beyond a threshold value had no beneficial effect on permeate flux recovery.
The effect of ozone on the levels of degradation of the NOM and the minimum threshold concentration required for effective degradation was determined. Ozonation resulted in a significant decrease in the level of the dissolved organic carbon and the effective conversion of humic substances to non-humic substances. Ozonation also resulted in the formation of partially oxidized compounds from NOM that were less reactive with chlorine, decreasing the concentration of total trihalomethanes and haloacetic acids. This study showed that an ozone/membrane filtration system required a minimum ozone dose of 1.5 g/m3 and a 5 kD membrane to reduce the DBP levels in the water sample to acceptable levels under the Safe Drinking Water Act.
A coating process is being developed for the alumina/zirconia/titania (AZT) nanocrystalline ceramic membranes purchased from a commercial supplier. Initially, an iron oxide nano-sized powder was fabricated in our laboratories, but this powder was found to be too highly agglomerated as well as too time consuming to produce. Instead, we now purchase the iron oxide nanopowders from a commercial supplier (Aldrich). The surface potential has been measured for both the iron oxide powder and the AZT membrane. This potential, along with additional data such as the dielectric constant, temperature, and ionic strength of the suspending fluid, have been used to estimate the pH at which the iron oxide powder will be suspended and to coat the AZT membrane. A firing schedule has been developed for these coated membranes, which has resulted in an adherent coating of iron oxide on the AZT membrane. In the coming year, we will concentrate on minimizing this coating thickness, while assessing the coating properties and integrity, in order to optimize its filtration abilities.
Future Activities:
In the next year, efforts will be focused on:
1. A major goal of the proposal is to develop catalytic membranes. Work will continue to create a catalytic membrane by coating an existing membrane with a thin layer of catalyst.
2. The transmembrane pressure, which is an operational parameter that influences permeate flux and can be an indicator of membrane fouling, should be monitored.
3. As bromide not only reacts with ozone and forms bromate, but also affects the formation of other DBPs, it is important to investigate the applicability of this system on waters containing high bromide concentrations.
4. The economic analysis needs to be conducted when cost-related information of ceramic membrane is available.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
| Other project views: | All 10 publications | 5 publications in selected types | All 5 journal articles |
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Karnik BS, Davies SH, Chen KC, Jaglowski DR, et al. Effects of ozonation on the permeate flux of nanocrystalline ceramic membranes. Water Research 2005;39(4) :728-734. |
R830908 (2003) R830908 (2004) |
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Supplemental Keywords:
groundwater, chemicals, oxidants, pathogens, viruses, bacteria, nanotechnology, disinfection, oxidation, ecosystem protection/environmental exposure and risk, international cooperation, sustainable industry/business, water, analytical chemistry, chemical engineering, chemistry, chemistry and materials science, drinking water, engineering, environmental chemistry, environmental engineering, environmental monitoring, monitoring/modeling, new/innovative technologies, physics, analytical methods, disinfection byproducts, DPBs, disinfection of waters, drinking water contaminants, drinking water treatment, environmental measurement, health effects, heavy metals, membrane filtration, nanocrystalline ceramic membranes, nanocrystals, nanoengineering, nanotechnology,, Sustainable Industry/Business, RFA, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, INTERNATIONAL COOPERATION, Water, Chemical Engineering, Environmental Chemistry, Engineering, Chemistry, & Physics, Monitoring/Modeling, Drinking Water, New/Innovative technologies, Environmental Engineering, Environmental Monitoring, health effects, ozonation, water quality, membrane filtration, disinfection by-products, analytical methods, nanoengineering, nanotechnology, drinking water contaminants, drinking water treatment, analytical chemistry, nanocrystals, nanocrystalline ceramic membranes, disinfection byproducts (DPBs), DBP exposureProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.