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World Water Day 2022

March 22 is United Nations' World Water Day and this year's theme is groundwater. It's a great opportunity to hear from Pacific Northwest National Laboratory (PNNL) experts about their numerous capabilities specific to the water that is found underground.

FoundUndergroundCampaign

United Nation’s World Water Day 2022 is the perfect opportunity to highlight how PNNL works collaboratively with sponsors like the DOE to help protect groundwater, a precious resource that is found underground.

(Images by Donald Jorgenson | Pacific Northwest National Laboratory)

March 22, 2022

We asked three groundwater researchers, Carolyn Pearce, Glenn Hammond, and Radha Kishan Motkuri about PNNL's capabilities that span bench-, pilot-, and field-scale research. Listen in and then read below to hear how their work is helping sponsors make scientifically-informed decisions on groundwater cleanup remedies.

(Audiogram compilation by Sara Levine | Pacific Northwest National Laboratory)
WWD_CarolynPearce

It Starts in the Lab...

Carolyn Pearce

Scientist, Subsurface Systems;
Director, IDREAM Energy Frontier Research Center

Which PNNL groundwater capabilities do you contribute to?

I contribute to the Pacific Northwest National Laboratory (PNNL) capability where we look, in situ, at what contaminants are found underground and how they move through the ground and into the groundwater. We’re then working to predict and engineer that movement so that we have control over the source of those contaminants to groundwater.

What problems do PNNL groundwater capabilities address?

We need to understand how contaminants move through the subsurface to prevent further groundwater impact. PNNL supports development of in situ remediation approaches to stabilize contaminants and stop them from reaching groundwater. And if they do, we need to make sure they're not going to exceed any drinking water standards. PNNL supports improvements to a pump-and-treat capability used to extract contaminants before returning clean water underground.

What is noteworthy about PNNL’s groundwater methods? How are you approaching what’s found underground from a fundamental science approach?

We’ve developed materials that can capture multiple contaminants, including developing one that's based on the element bismuth. It's a bismuth oxyhydroxide material that's actually really good at removing negatively charged species from solution. A lot of the contaminants found underground that we're interested in at the Department of Energy’s Hanford Site are those negatively charged ions. We've developed this capability in the laboratory and we're working on ways to deploy it to the subsurface to treat hot spots where there are high concentrations of those contaminants. We use these materials to stabilize the contaminants and stop them from progressing into groundwater.

What are the impacts of your work?

Here in Washington State, as PNNL’s Deep Vadose Zone-Applied Field Research Initiative develops the technical basis to remediate contaminants found underground in the subsurface. It ultimately helps protect not only the groundwater, but also the Columbia River, which is the largest river in the Pacific Northwest region of North America. These same methods can be more broadly utilized to prevent groundwater contamination in numerous areas. We're also investigating ion exchange resins that are designed to remove several different contaminants, pumping up groundwater and using the resin to remove multiple contaminants, so we can subsequently pump the clean water back into the ground.

What do you want people to know, act, or do as a result of this campaign?

People can work to better understand what potential risks are being posed to groundwater and what's being done to mitigate those risks. Also, understanding that groundwater is an extremely precious resource. In the past, society has carried out activities that put our water found underground at risk and we need to learn from that. We’re developing better strategies to make sure groundwater is protected—we now know how to do that safely and efficiently.

Carolyn's Related Resources 

IDREAM 
IDREAM_200x150
Mastering
fundamental interfacial
chemistry in complex
environments.
journal article 
Technetium_ACS_200_Top
Characterizing Technetium in Subsurface Sediments for Contaminant Remediation
 journal article 
PoreScaleCharacterization_200x150
Pore-Scale Characterization of Biogeochemical Controls on Iron and
Uranium Speciation under Flow Conditions
journal article 
SubsurfacePlutonium_200x150
Influences on Subsurface Plutonium and Americium Migration
research highlight
Water Desorption_200
Novel Energy Exchange Mechanisms Lead to Water Ionization and Desorption from Nanoparticle Interfaces.

 


 

GHammond_FoundUnderground

Modeling is Where It’s At...

Glenn Hammond

Computational Geohydrologist and Senior Research Scientist 

Which PNNL groundwater capabilities do you contribute to?

I develop the groundwater simulator PFLOTRAN, a code that leverages a supercomputer to simulate the flow of water in the subsurface, as well as water and soil chemistry. More recently, we've implemented the ability to simulate electrical resistivity, a soil property that can be measured over large areas, to help detect potentially contaminated subsurface sites.

Why is it important to simulate the flow of groundwater?

When we simulate the flow of groundwater, we’re looking at the impacts of climate change on bodies of water, particularly river bodies and water that infiltrates out of rivers into the ground. There's an exchange going on there and there's carbon turnover that we track. We're also looking at contamination in the Earth's subsurface, looking at nuclear waste disposal sites that are found underground, including deep geologic repositories for the most hazardous waste. We’re looking at how long it will take contaminants from those repositories to reach a drinking water well. We simulate for up to one-million years, seeing if any of that waste ever reaches a well.

What’s next for groundwater modeling?

We’re working toward advanced methods for subsurface imaging that I really believe in, particularly in using electrical resistivity tomography to image the subsurface in 3D. We are using this modeling to ground truth our groundwater models, which is a huge improvement in technology as far as modeling goes.

Who benefits from your work?

What makes my day is when someone sends me an email saying they picked up the code and they like it, but they just need a little bit of help. They’re applying the code to a complex situation and this is the first time modeling is available to them. I help them advance their idea further, giving them a snippet of advice. They take it and run with it and later I hear about what they were able to accomplish and how cool it turned out—I will say that is one of the most satisfying aspects of developing PFLOTRAN. People from around the world using and enjoying the code; that's far better than a paycheck honestly.

Glenn's Related Resources 

INduced Spectral 
Interrogation 
Technology for the Environment
INSITE_200
Revolutionizing how the subsurface environment is interrogated and understood.
pflotran
PFLOTRAN_200
Open source, state-of-the-art massively parallel subsurface flow and reactive transport code.
 journal article 
PFLOTRANJournal
A parallel open source PFLOTRAN module for simulating time-lapse electrical resistivity data.
book chapter 
ReactiveTransport_200
Reactive Flow & Transport Code for Use on Laptops to Leadership-Class Supercomputers
journal article
PFLOTRANJournal2
An Ensemble-based Data Assimilation System for Estimating Subsurface Flow and Transport Model Parameters.

 


 

RMotkuri_FoundUnderground

Detection in the Field...

Radha Kishan Motkuri

Senior Chemical Engineer, Material Scientist

Which PNNL groundwater capabilities do you contribute to and what problems do these capabilities address?

I am specifically working on technologies to detect, capture, and destruct PFAS, which are chemicals found underground that can be harmful to humans. PFAS are persistent in our environment as they are chemicals used in all types of materials, from firefighting foams to fabric protectors, in pizza boxes and coffee mugs, and items covered in Teflon. And they have one of the strongest carbon fluorine bonds in organic chemistry, which means they are highly water soluble and very ubiquitous in the environment. Continued usage of these materials has increased the PFAS contamination in groundwater, which can then end up in humans.

What is the biggest misconception you frequently deal with?

In the PFAS space, people think existing groundwater contamination purification technologies might be used to remediate PFAS. But, these technologies don’t account for such ultra-low concentrations associated with PFAS which are parts per trillion—more like a speck of a granule of sugar or salt in the Olympic-sized swimming pool. The existing technologies are typically applied to contaminants at parts per million and some to parts per billion levels only. Applying the right technology will be like choosing the right hammer for a right-sized nail.

How are PNNL’s capabilities different?

PFAS found underground require three main things—detection, capture, and destruction. In collaboration with the New Jersey Institute of Technology, PNNL worked to combine multiple technologies—nanoporous material adsorption/desorption, a microfluidic device, and an impedance analyzer—into a single sensor device to offer detection at a level that’s parts per trillion (several orders of magnitude lower than the Environmental Protection Agency’s health advisory level for drinking water).

Who will benefit from your work?

People all over the world, including in the United States, will benefit from this work as PFAS contamination is becoming a major global problem. People continue to use and dispose of materials containing cancer-causing PFAS. These wastes are migrating into groundwater and then back to the surface as drinking water and into the human body. PNNL’s FAST PFAS sensor allows us to map the PFAS and understand how they are transported. Once we find a PFAS concentration at a particular site, then we have the technology to capture them, followed by destruction.

What’s next for PFAS remediation?

Right now, people are taking samples found underground and sending them to an accredited laboratory for PFAS testing, which takes three- to five-business days and costs hundreds of dollars. With our FAST PFAS sensor technology, we can detect PFAS in the field within 30- to 60-minutes. That saves a lot of time and money. We’re also implementing remote operation and autonomous sensing by integrating Wi-Fi ability, modeling tools for surface mapping, machine learning, and artificial intelligence.

Radha's Related Resources 

podcasts
DisruptingPFAS_200
Motkuri on National PFAS Podcast
fast pfas sensor
RD1002021
Fast PFAS Sensor: Forever-Chemicals Finder
 web feature
PFAS522
Detecting Toxic PFAS with a Chip-Sized Sensor
news release
InorganicChemistryCover
Nanoporous Material Nets Contaminant from Water
patent
Environment
Composition and Method for Capture and Degradation of PFAS

 


Subsurface@PNNL Newsletter

SubsurfacePNNLNews

Subsurface@PNNL takes research underground, providing an in-depth understanding of natural and engineered subsurface systems. Its “science-to-solutions” approach can be applied to improve the way subsurface contaminants are remediated and isolated, legacy waste is stored and disposed of, and energy sources are accessed and extracted.

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PNNL’s groundwater capabilities are integral to its complex subsurface environmental systems research and development portfolio. The portfolio represents a multidisciplinary team of scientists, engineers, and professional staff from across the Laboratory who develop innovative solutions that provide the technical foundation for solving sponsor and client’s subsurface and groundwater challenges. To learn more, visit PNNL's Subsurface Science web page.