Addressing Longstanding Groundwater Contamination using Silica Polyamide Composites in the Tsétah Area in Arizona

EPA Grant Number: FP917795
Title: Addressing Longstanding Groundwater Contamination using Silica Polyamide Composites in the Tsétah Area in Arizona
Investigators: Tsosie, Ranalda L
Institution: University of Montana
EPA Project Officer: Lee, Sonja
Project Period: September 1, 2015 through August 31, 2018
Project Amount: $132,000
RFA: STAR Graduate Fellowships (2015) RFA Text |  Recipients Lists
Research Category: Academic Fellowships

Objective:

Groundwater and surface water contamination caused by heavy metal ions such as arsenic, copper, chromium, uranium and other metals remains an environmental concern. These concerns are especially evident in smaller communities. Addressing the longstanding groundwater contamination issues that the communities in the Tsétah area in Arizona is of great interest. Previous studies have determined the extent of contamination in unregulated wells, but a project that addresses the problem has not yet been enacted. Therefore, the objectives of this study are: 1) to determine the geochemical characteristics of unregulated and regulated water sources in the Tsétah area in northeastern Arizona; 2) to analyze the potential for silica polyamine composites (SPC) as a method of remediation. By remediation, the fellow is referring to the concept of restoring the drinking water quality (Environmental Protection Agency Maximum Contaminant Level standards) by removing the heavy metals that pose a concern for human exposure; and 3) to optimize SPC technology as a point of use filter for the removal of contaminants from wells located in the prospective study site.

Approach:

The design of this study has two essential phases. The first phase is an exploratory study that involves the investigation of unregulated and regulated water sources located within 15 miles of the Tsétah Wash study site. These initial trips to the study site are necessary to obtain a preliminary picture of the levels of heavy metals in order to refine later sampling. Field sample collections will be completed during the Spring of 2016 and 2017, during Spring runoff and Summer monsoon. Field sample collections will be repeated during the Summer of 2016, through early Fall of 2016.

The second phase will address research objective 2. The Rosenberg research group has previously designed and synthesized a variety of SPCs, the proposed study will begin by implementing these SPCs as a starting point. It will also encompass the assessment of SPCs and their ability to selectively remove heavy metal ions from confirmed contaminated water samples. These analyses will include metal ion separation tests. This test will be implemented by first examining which SPCs are the most effective at removing various metal ions. The overall test may include one or more columns packed with functionalized SPCs, batch equilibrium, adsorption isotherm and pH profiles.

Expected Results:

It is expected that the concentrations of uranium, arsenic and other metals in the water sources (wells) examined will be reduced to below the EPA's recommended drinking water quality and maximum contaminate level standards. It is also imperative that this technology and materials be economically viable and can be used in a variety of environmental settings whether it be point of use wells both private and public, in homes, housing developments and other locations where water is obtained.

Supplemental Keywords:

Silica Polyamine Composites, Heavy Metals, Removal and Recovery, Point of Use filters

Progress and Final Reports:

  • 2016
  • 2017
  • Final