Superfund Research Program
Novel Rhamnolipid Surfactants for Recovery of Critical Elements and Remediation of Metal Contaminated Waste Streams
Project Leader: Chett Boxley
Grant Number: R43ES029423
Funding Period: Phase I: March 2018 - August 2019
Industrial processes produce difficult-to-treat wastewater that may contain environmental contaminants in the form of dissolved metals, many of which pose a potential health hazard to plants, animals, and humans. Examples include mining industry effluents, wastewater treatment effluents, and landfill leachates. In many cases, these waste streams cannot be treated cost effectively. Consequently, massive quantities of wastewater are quarantined for expensive treatment and subsequent discharge, disposed of underground, or discharged into the surface water supply leading to a significant impact on environmental and human health.
Remediation of these waste streams is traditionally accomplished through a variety of technologies ranging from chemical precipitation to membrane filtration. The technology used is highly dependent on the effluent type, and each technology has intrinsic advantages and drawbacks. While chemical precipitation is simple and capital investments are inexpensive, it is an inefficient process at low metal concentrations, non-selective, and generates large amounts of sludge which requires subsequent treatment. On the other hand, membrane filtration technologies have high metal removal efficiencies and generate minimal waste, but they are extremely expensive to operate, have high operational complexity, and suffer from membrane fouling.
This project combines a proprietary process to manufacture green bio-inspired metal-selective sugar-based surfactants with ion flotation technology for efficient and cost-effective removal of toxic metals and rare earth elements (REE) from wastewater. This new technology will create a saleable product of metals of strategic importance to the U.S. and facilitate water reuse through removal of toxic metals from waste streams. Preliminary data using simple solutions has demonstrated that biosynthetic rhamnolipids are highly effective at capturing both REEs and heavy metals, even in the presence of common soil cations such as sodium, potassium, and calcium.
GlycoSurf and its University of Arizona partner aim to:
- Characterize effluent from model and real-world solutions,
- Characterize metal removal from model and real-world solutions via ion flotation, and
- Evaluation the performance and estimate costs for scale-up.
Successful completion of these aims will facilitate the pathway to commercialization of the novel technology to protect water supplies (and ultimately human and environmental health), while simultaneously creating a novel pathway for the production of saleable REE.