Grantee Research Project Results

Optimization of Natural Photochemistry for Cost-Effective, Energy-Efficient Human Pathogen Inactivation in Compromised Water Sources

EPA Grant Number: FP917094
Title: Optimization of Natural Photochemistry for Cost-Effective, Energy-Efficient Human Pathogen Inactivation in Compromised Water Sources
Investigators: Fagnant, Christine Susan
Institution: University of Washington
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 2010 through August 31, 2013
Project Amount: $111,000
RFA: STAR Graduate Fellowships (2010) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Drinking Water

Objective:

This research project will aim to optimize natural processes to develop simple, sustainable, and inexpensive water disinfection processes that could be used in both the developed and developing worlds.

Synopsis:

This project will examine the use of natural chemical reactions to develop simple, inexpensive, and low-energy water disinfection systems. The research will focus on the utilization of metals (e.g., iron or aluminum) and/or various organic photocatalysts to produce chemical disinfectants in the dark and under the influence of direct solar irradiation. These processes are ultimately intended for application in point-of-use drinking water treatment and/or sanitation in developing communities.

Approach:

Bench-scale experiments will examine the ability of redox systems catalyzed by transition metals (such as iron or aluminum) and/or organic photosensitizers to produce water disinfectants such as hydrogen peroxide or chlorine with minimal or no electrical input. Both sunlight-mediated and dark reactions will be investigated. Furthermore, this research will examine the effects of coupling such chemical disinfectants with solar disinfection of water for enhanced pathogen inactivation. After bench-scale models are developed, scaling of these processes for point-of-use water treatment will be investigated. Materials utilized in these experiments will be selected on the basis of their ready availability and affordability in diverse geographical regions.

Expected Results:

This research is expected to yield inexpensive, simple, and sustainable means of generating chemical disinfectants. These processes will be optimized to produce disinfectants at concentrations appropriate for water treatment applications. The processes developed during this work will be simple to operate and appropriate for use in developing communities. The findings obtained from this work will also provide important fundamental insights into chemical and photochemical processes relevant to various other applications in environmental chemistry and engineering (e.g., iron and aluminum corrosion, transition metal photochemistry, photosensitized chlorine production in marine waters).

Potential to Further Environmental/Human Health Protection:

This research will facilitate the development of simple, point-of-use water disinfection systems, thus contributing to improvement of the health and safety of people in developing communities through reduction of gastrointestinal and other waterborne diseases. These benefits could be amplified through use of disinfectants for improved sanitation. Furthermore, this research will contribute to the development of more sustainable methods for chemical disinfectant generation in general water treatment practice, potentially resulting in significant reductions of harmful greenhouse gas emissions.

Supplemental Keywords:

water treatment, disinfection, sanitation, iron, aluminum, chlorine, hydrogen peroxide, photochemistry, SODIS, compromised waters, appropriate technology, developing communities,

Progress and Final Reports:

2011

2012

Final