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--- writing:phytoremediation [2026/02/19 20:41] – [Resources] JacobCoffinWrites
+++ writing:phytoremediation [2026/02/20 14:59] (current) – [What is Phytoremediation] JacobCoffinWrites
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 ==== What is Phytoremediation ====
-Phytoremediation is the practice of using living plants to clean soil, air and water contaminated with hazardous substances. Plants can help clean up many types of contaminants including heavy metals, pesticides, explosives, and oil. However, they work best where contaminant levels are low because high concentrations may limit plant growth and take too long to clean up. Plants can also help prevent wind, rain, and groundwater flow from carrying contaminants away from the site to surrounding areas or deeper underground.
+Phytoremediation is the practice of using living plants to clean soil, air and water by absorbing or breaking down hazardous contaminants.
+Plants can help clean up many types of contaminants including heavy metals, pesticides, explosives, and oil. However, they work best where contaminant levels are low because high concentrations may limit plant growth and take too long to clean up. Plants can also help prevent wind, rain, and groundwater flow from carrying contaminants away from the site to surrounding areas or deeper underground.
 At its core principle, phytoremediation focuses on the ability of some plants to uniquely tolerate environmental pollutants.
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 ==== Types of Phytoremediation ====
-=== Phytoaccumulation ===
+=== Phytoaccumulation/Phytoextraction===
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 === Phytomining ===
-[[https://en.wikipedia.org/wiki/Phytomining|Phytomining]], also known as Agromining, is another quite new field, looking to obtain various metals for industrial purposes using plants. It is currently the subject of several research studies, including ones attempting to genetically modify more effective plants, and it seems like its overall viability is still undetermined at this time.
+[[https://en.wikipedia.org/wiki/Phytomining|Phytomining]], also known as Agromining, is another quite new field, looking to obtain various metals for industrial purposes using plants. It is currently the subject of several research studies and startups, including ones attempting to genetically modify more effective plants, and it seems like its overall viability is still undetermined at this time.
-It is included in this list because the harvested hyperaccumulators need to be sent somewhere for containment, and it's possible that any industrial experience gleaned in commercial phytomining work will be useful in separating the contaminants from the plant matter. This would be ideal because reducing the mass of organic matter needing long-term storage will reduce both waste and cost. It may even be able to turn a waste product into a useful input in industry.
+It is included in this list because the harvested hyperaccumulators need to be sent somewhere for containment, and it's possible that any industrial experience gleaned in commercial phytomining work will be useful in separating the contaminants from the plant matter. This would be ideal because reducing the mass of organic matter needing long-term storage will reduce both waste and cost. It may even be able to turn a waste product into a useful input in industry as many heavy metals have manufacturing uses.
 === Phytovolatilization ===
-[[https://pubs.acs.org/doi/10.1021/acs.est.5b04113|Some plants take up contaminants from the soil and release them into the atmosphere]]. This can be a good thing, such as [[https://repository.lib.ncsu.edu/server/api/core/bitstreams/58fa0ea2-71dd-4b3d-9892-9f355c24e670/content|when the contaminant is something like Dioxane which can be photodegraded and has a half-life measured in hours to days]] but it can also be a problem, like [[https://pmc.ncbi.nlm.nih.gov/articles/PMC7967564/#sec3-ijerph-18-02435|when the contaminant is a heavy metal]]. Aerosolized mercury may be enough of a hazard to rule out some phytoremediation candidates.
+Some plants take up contaminants from the soil and release them into the atmosphere - this is known as [[https://pubs.acs.org/doi/10.1021/acs.est.5b04113|Phytovolatilization]]. This can be a good thing, such as [[https://repository.lib.ncsu.edu/server/api/core/bitstreams/58fa0ea2-71dd-4b3d-9892-9f355c24e670/content|when the contaminant is something like Dioxane which can be photodegraded and has a half-life measured in hours to days when exposed to sunlight]] but it can also be a problem, like [[https://pmc.ncbi.nlm.nih.gov/articles/PMC7967564/#sec3-ijerph-18-02435|when the contaminant is a heavy metal]]. Aerosolized mercury may be enough of a hazard to rule out some phytoremediation candidates. So far it seems like most of the time when I see phytovolatilization mentioned in a phytoremediation paper the authors are treating a low phytovolatilization rate as being a good thing but it definitely varies by contaminant.
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-===Phytodegradation ===
+===Phytodegradation/bioremediation ===
+Out of all these options, this is probably the closest fit to "remediation" in "phytoremediation." [[https://en.wikipedia.org/wiki/Phytoremediation#Phytodegradation|Phytodegradation]] is a process where plants absorb organic pollutants and break them down into less harmful substances through metabolic processes or by releasing enzymes. It's not possible for every contaminant (for example, most? all? heavy metals) but for organic ones like Dioxins or VOCs, it can be a pretty miraculous. We'll talk more about bioremediation through fungus and bacteria in the next sections, it seems like they may be even better for this work. For example, liginolytic fungi evolved to digest tree lignin, one of the complex, tough organic polymers used by trees to make strong wood. Lignin is unusually hard to break down, and the chain of tools some of the fungis developed is so powerful it is general purpose, enabling them to break down many organic chemicals (like dioxins).
-Plants produce enzymes that can break down contaminants into less harmful compounds
 ===Hydraulic Control ===
-This isn't necessarily a type of remediation on its own, but it also can be.
+There are other ways to utilize plants in environmental remediation. One of the big challenges of restoring contaminated land is managing the flow of groundwater below the site - many contaminants are quite stable underground, meaning they'll persist and remain dangerous for a very long time, and they can often spread and migrate with the groundwater flow. This plume can eventually contaminate wells and underground aquifers people rely on for drinking water and emerge from springs into surface water bodies.
+Certain plants, such as poplar trees, can be used as natural water pumps, operating so well during their growing season that they can actually [[https://www.cluin.org/download/studentpapers/vandenbos.pdf|reverse the flow of groundwater]].
+This was used to interesting effect in [[https://www.wsp.com/en-us/projects/leveraging-nature-to-help-solve-the-pfas-puzzle-in-groundwater|this project]], which used biochar to trap PFAS in groundwater, and used poplar trees to draw groundwater into that 'trap'.
+It's important to note that the efficacy of these projects varies by site and it can be hard to tell why the trees seem serve as an excellent barrier in one case, and have minimal impact in others.
 ==== Other Types of Bioremediation ====
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-==== Finding Premeditation Options That Fit Your Story and Setting ====
+==== Finding Phytoremediation Options That Fit Your Story and Setting ====
-Bioremediation/Phytoremediation is a very new field, with tons of ongoing research. Fortunately much of that research is publicly available, though it’s often dense and somewhat hard to understand. And because it's often focused on lab results, it can be hard to glean details of what actual remediation in the field would look like.
+Bioremediation/Phytoremediation are very new fields, with tons of ongoing research. Unless you go in with very specific requirements already in mind, you'll likely notice that there's an almost overwhelming number of options and variables to consider - there are hundreds of contaminants of concern, far more species that may work on them, and complex relationships where some species work on some contaminants but will be poisoned by others, or work best when supported by other species. Add to that concerns about accidentally importing invasive species and it can become quite a tangle. This isn't helped by the density of academic research language and the fact that these reports are often short on the sort of details which help when planning/writing depictions of remediation work in the field.
-The challenge is that there are absolute tons of contaminants out there, and far more plants that effect them in some way (and are effected by them in turn). Furthermore, these plants are part of a complex ecological network and
+=== My workflow for finding suitable plants while not going insane ===
-**My workflow for finding suitable plants while not going insane:**
 Start with the contaminant of concern. Pick your poison, then look up which plants can be used to remediate, accumulate, or stabilize it.
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 There are so many plants, contaminants of concerns, and varying ways the two interact that it really does need some review
-====Resources ====
-[[https://en.wikipedia.org/wiki/List_of_hyperaccumulators|Wikipedia's list of known hyperaccumulators]]
+==== General details which might be useful ====
+**Bioremediation** - [[https://www.sciencedirect.com/science/article/pii/S2666821122001193|This paper]] provides a detailed description and diagrams of the process of introducing bioremediation bacteria to contaminated aquifers. It includes details on the arrangement of wells for testing and remediation. The paper is about dechlorinators but it seems likely that other groundwater bioremediation projects might follow similar steps.
+  - Test the groundwater to determine the level of contamination and extent of the plume
+  - Test for the presence of suitable bioremediation bacteria (and the symbiotic bacteria which enable them). Using native bacteria already present in the groundwater is preferred. Bacteria can also be invasive.
+      * If they are present, test to determine what, if any, chemical nutrients/additives/remediation would help them to thrive and work quickly
+      * Biostimulation - pump the necessary solution into the aquifer
+  - If the concentration of contaminants is too high, or the right mix of dechlorinators aren’t present, they would try bioaugmentation - injecting pre-grown dechlorinator cultures along with the necessary substrate.
+[[https://www.epa.gov/sites/default/files/2015-04/documents/engappinsitbio.pdf|This older report]] provides some similar information.
+====Resources ====
-[[https://docs.google.com/document/d/1vsbsZKa3q9bUwm9PnnEayDuQGLFi-HKIqSYYv8J7cy8/edit?usp=sharing|This document]] is an open source attempt to collect options for the bioremediation of dioxin, vinyl chloride and related toxins.
+  * [[https://en.wikipedia.org/wiki/List_of_hyperaccumulators|Wikipedia's list of known hyperaccumulators]]
+  * [[https://docs.google.com/document/d/1vsbsZKa3q9bUwm9PnnEayDuQGLFi-HKIqSYYv8J7cy8/edit?usp=sharing|This document]] is an open source attempt to collect options for the bioremediation of dioxin, vinyl chloride and related toxins.
+  * The following documents provide decent lists of likely contaminants produced by internal combustion engine automobiles (such as you might find in a scrapyard, salvage operation, or car graveyard).
+      * https://www.epa.gov/sites/default/files/2015-10/documents/sector_m_autosalvage.pdf
+      * https://web.archive.org/web/20230309211038/https://eeuroparts.com/blog/how-toxic-are-the-chemicals-in-your-car/
+  * [[https://nepis.epa.gov/Exe/ZyNET.exe/940082TP.txt?ZyActionD=ZyDocument&Client=EPA&Index=1995%20Thru%201999&Docs=&Query=%28%28deep%20rooting%29%20or%20%28deep%20rooting%29%29%20OR%20FNAME%3D%22940082TP.txt%22%20AND%20FNAME%3D%22940082TP.txt%22&Time=&EndTime=&SearchMethod=1&TocRestrict=n&Toc=&TocEntry=&QField=&QFieldYear=&QFieldMonth=&QFieldDay=&UseQField=&IntQFieldOp=0&ExtQFieldOp=0&XmlQuery=&File=D%3A%5CZYFILES%5CINDEX%20DATA%5C95THRU99%5CTXT%5C00000042%5C940082TP.txt&User=ANONYMOUS&Password=anonymous&SortMethod=h%7C-&MaximumDocuments=1&FuzzyDegree=0&ImageQuality=r75g8/r75g8/x150y150g16/i425&Display=hpfr&DefSeekPage=&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=34&SeekPage=f|This paper]] has some details on deep rooting poplar trees.
 ==== Other concerns ====