One in a Billion: Living Filters for Arsenic Removal

EPA Grant Number: SV840018
Title: One in a Billion: Living Filters for Arsenic Removal
Investigators: Colvin, Vicki L.
Institution: Brown University
EPA Project Officer: Aja, Haley
Phase: II
Project Period: July 1, 2020 through June 30, 2022
Project Amount: $75,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2020) Recipients Lists
Research Category: P3 Awards

Objective:

This project will address problems related to basic sanitation and drinking water for homes in disadvantaged and rural communities. Detecting and removing trace levels of toxic heavy metals from water in the presence of other abundant and safe constituents demands selectivity. While extremely expensive options like reverse osmosis can be applied, the working lifetime is not always predictable or reliable if the input water has variable composition. Researchers hypothesize that engineered bacteria can hyperaccumulate arsenic from drinking water with a performance independent of water quality; moreover, researchers expect these organisms will remain alive during remediation offering a path towards renewable sorbent material on demand. To limit the release of sorbents, researchers will compare conventional filtration as well as magnetic and membrane-based separation strategies.

Approach:

Researchers will design microbes to produce large quantities of naturally occurring and optimized arsenic-binding proteins and alter their growth conditions to optimize intracellular arsenic uptake. Their function as sorbents will be evaluated under both laboratory conditions as well as in more diverse waters and media. Researchers will compare the efficacy of magnetic as well as physical filtration for microbe removal from effluents.

Expected Results:

We expect these microbes will act as living filters, capable of 100% removal of very low levels (< 10 ppb) of arsenic even in the presence of interfering anions. If removal speed is not an issue, we will describe how a teabag can be used for containing microbes; if faster separation is desired, we will label bacteria with iron oxide nanoparticles to make them magnetic. These living systems will demonstrate for the first time how to form an arsenic removal material that operates identically under a wide range of solution conditions. This advance will enable community-based arsenic treatment that is sustainable, inexpensive and effective.

Supplemental Keywords:

Water treatment, arsenic, groundwater, nanotechnology, biotechnology


P3 Phase I:

Magnetic Nanocomposites for Water Remediation  | Final Report