Light-Based Approaches to Effective and Sustainable Removal of Arsenic and Uranium from Drinking Water Sources

Project 5 Summary
The Columbia University Northern Plains Superfund Research Program (CUNP-SRP) seeks to reduce exposure
to arsenic (As) and uranium (U), frequently found in excess of safe limits on tribal lands in North and South
Dakota and elsewhere. In these areas, drinking water is primarily derived from groundwater. This reliance often
results in people using untreated or insufficiently treated water from private wells that is unfit for consumption.
Community water systems (CWSs) also use groundwater and often fail to limit As and U contamination to safe
levels despite treatment. Inadequate removal of As and U by conventional water treatment stems from the limited
adsorption of their most abundant forms in groundwater, As(III) and U(VI), and due to the limited sorption capacity
of media. Importantly, these As and U exposures are associated with cardiometabolic disease, which exerts a
disproportionately high burden in Native American populations. The overall goal of Project 5 is to decrease
exposure using novel point-of-use filtration and point-of-entry treatment systems that use light to create media
and enhance As and U sorption by simultaneously oxidizing As and reducing U. Our technology is based on an
efficient, photosynthetic microbial battery that generates reactive treatment media by cycling iron (Fe), which is
ideal to remove chemical contamination from groundwater. This approach takes advantage of the aqueous
composition of input water and microbial communities, which often contain reduced forms of Fe(II) and
manganese (Mn(II)) and/or nitrate, in addition to metal(loid) contaminants. Specific aims will address the
underlying processes to optimize this novel water treatment technology and the necessary monitoring needed
to ensure system performance. In Aim 1, media will be generated by harnessing natural microbial populations
from groundwater that are powered by light and the chemical energy stored within water to create Fe oxide
media. In Aim 2, enhanced treatment will be obtained through heterogeneous photocatalysis that selectively and
simultaneously can reduce and oxidize groundwater contaminants to less soluble forms. In Aim 3, we will develop
and integrate a real-time, water quality monitor in the treatment system to ensure that the system performs to
specifications and to be able to alert the user and/or water treatment company before the system fails. Each aim
targets development of a commercially viable product. This project remediates As and U in groundwater,
common contaminants at Superfund sites and some of the most widespread contaminants in the US, especially
in rural communities. These remediation approaches will be tested and implemented in the Northern Plains in
areas with As and/or U affected drinking water. Implementation will allow us to pilot the use of this novel treatment
method under a wide range of water compositions and with typical use patterns. Ultimately, the novel water
remediation technologies developed in this project are expected to provide a feasible and effective means to
reduce potentially harmful exposures to drinking water contamination in our target communities and other at-risk
populations, including communities near Superfund and other hazardous sites.

Grant Number: 5P42ES033719-04
NIH Institute/Center: NIH
Principal Investigator: Benjamin Bostick