This presentation focused on a practicality that can be implemented in any Permaculture design. Phytoremediation is a revolutionary process that heals environments and directs its primary focal point on helping habitats thrive. As a group we decided to inform the class on how Phytoremediation is being used and ways to improve small scale agriculture in a sustainable way.
The arrangement of slides above is put together in three separate categories. The introduction centers around what Phytoremediation is and diagrams depicting Phytoremediative projects. The second part of the slideshow brings attention to Agroforestry and how phytoremediation can be used within the methods of Agroforestry. The last piece of the presentation concentrates on pond methods and how Phytoremediation is being used today.
Within our group three concepts mentioned in the slideshow above were collaboratively introduced. We decided that connecting Phytoremediation to different Permaculture designs would bring insight to the class for future applications. The presentations message was that small practical contraptions and innovative tools could create a future that may help save the planets health.
By sharing with our peers how small scale systems can be introduced we hope that they also share with other individuals to utilize these methods. If all people begun to stray from the path of destroying the Earth and created better ways to dispose of waste, we could slow down the rate of destruction. Permaculture design and organic-agricultural movements are great examples to share with hope for this planet.
As a group we feel that concepts like these must be presented to society. Our presentation was a glimpse of how much work needs to be, and can be done.
The arrangement of slides above is put together in three separate categories. The introduction centers around what Phytoremediation is and diagrams depicting Phytoremediative projects. The second part of the slideshow brings attention to Agroforestry and how phytoremediation can be used within the methods of Agroforestry. The last piece of the presentation concentrates on pond methods and how Phytoremediation is being used today.
Within our group three concepts mentioned in the slideshow above were collaboratively introduced. We decided that connecting Phytoremediation to different Permaculture designs would bring insight to the class for future applications. The presentations message was that small practical contraptions and innovative tools could create a future that may help save the planets health.
By sharing with our peers how small scale systems can be introduced we hope that they also share with other individuals to utilize these methods. If all people begun to stray from the path of destroying the Earth and created better ways to dispose of waste, we could slow down the rate of destruction. Permaculture design and organic-agricultural movements are great examples to share with hope for this planet.
As a group we feel that concepts like these must be presented to society. Our presentation was a glimpse of how much work needs to be, and can be done.
Using Phytoremediation to Clean Up Sites:
Phytoremediation is the direct use of green plants and their associated microorganisms to stabilize or reduce contamination in soils, sludges, sediments, surface water, or ground water. First tested actively at waste sites in the early 1990s, phytoremediation has been tested at more than 200 sites nationwide. Because it is a natural process, phytoremediation can be an effective remediation method at a variety of sites and on numerous contaminants. However, sites with low concentrations of contaminants over large cleanup areas and at shallow depths present especially favorable conditions for phytoremediation. Plant species are selected for use based on factors such as ability to extract or degrade the contaminants of concern, adaptation to local climates, high biomass, depth root structure, compatibility with soils, growth rate, ease of planting and maintenance, and ability to take up large quantities of water through the roots.
Oregon Poplar Site
The Oregon Poplar site, located in Clackamas, Oregon, comprises three to four acres within a vacant parcel located parallel to the small Mt. Scott Creek stream. The site had been an abandoned grassy field in a primarily commercial and light industrial area. Contaminants of concern at the site were primarily volatile organic compounds (VOCs), resulting most likely from illegal dumping activities. The ground water beneath the site is shallow (two to ten feet below the ground surface), locally confined, and in hydraulic contact with the Mt. Scott Creek stream. These characteristics along with low concentration of contaminants and little to no risk to human health make the site a good candidate for phytoremediation.
Hybrid poplar trees were planted on site in 1998 to remediate the ground water contaminated with VOCs. By July 30, 2002, the trees had not only survived, but shown considerable growth. Four of the larger trees were selected as the focus of sampling because their roots most likely be in contact with contaminated ground water. Although the water and soil samples proved inconclusive, tissue samples taken from the four trees indicated that the trees were actively removing VOCs from the ground water and soil. Although tissue samples from all sections of the trees revealed contaminant uptake, higher contaminant concentrations seemed to be found in the trunk rather than the leaf tissue. The picture above shows the collection of gas and water vapor from a poplar tree at the site. The success of the trees at the Oregon Poplar site supports the notion that phytoremediation may be an innovative technology worthy of nationwide consideration.
J-Field at Aberdeen Proving Ground
The once toxic pits of J-Field, located in the Edgewood area of Aberdeen Proving Ground, Harford County, Maryland, were used as a disposal site for chemical warfare agents, munitions, and industrial chemicals from 1940 through the 1970s. The two most prevalent contaminants of concern in the ground water at the site included Trichloroethene (TCE) and 1,1,2,2-tetrachloroethane (1122). In the Spring of 1996, a phytoremediation study was implemented to determine if the contaminants underlying J-Field could be removed through phytoremediation using various tree species.
Chosen for their rapid growth and high transpiration rates, 183 hybrid poplar trees were planted over an area of approximately one acre in 1996. VOCs and the chemicals they break down into have been detected in the leaf tissue and gas and water vapor expelled by the trees, indicating that the poplars are removing, degrading, and releasing the contaminants of concern. Sap flow rates and shallow ground water levels also indicate that the trees are intercepting and removing the contaminants from the site. Finally, it is possible that the trees may also be enhancing the soil community, although further investigation is needed to determine this. It is estimated that within 30 years, contaminants at J-Field may be reduced by up to 85 percent.
For more information on phytoremediation, download the Brownfields Technology Primer: Selecting and Using Phytoremediation for Site Cleanup . For more information on either of these phytoremediation sites, contact Harry Compton, U.S. EPA, (732) 321-6751, [email protected].
Using Native Plants in Phytoremediation
Use of native plants in phytoremediation provides advantages over other species and helps bring back the heritage of flora lost through human activity. In addition to restoring biodiversity to areas that have been disturbed, remediating Superfund sites using native species provides for wildlife habitat enhancement and conservation and saves money over alternative cleanup methods. Unlike many introduced species, once established, native plants do not require fertilize, pesticides, or watering. As encouraged by the Superfund Redevelopment Initiative, use of native plants in site restoration may serve to restore wetlands and other habitats and create nature parks, sanctuaries, and other green areas.
Two Presidential documents address the use of native species in Federal projects and their protection from invasive or introduced foreign species. The first is the April 26, 1994 "Memorandum on Environmentally Beneficial Landscaping". The second document is Executive Order 13112 of February 3, 1999 - Invasive Species. For more information on use of native plants in restoration of Superfund sites, contact Scott Fredericks, U.S. EPA, (703) 603-8771, [email protected]. You can also learn about phytoremediation work being done by some faculty members at the University of Washington.
Source: http://www.epa.gov/superfund/accomp/news/phyto.htm
MARCH 18, 2013
Practical Permaculture – Plants and Phytoremediation
Plant identification is an art in itself and honestly has to be taught by physically seeing the plant, I have been to a million lectures with someone flipping through slides and talking about different plants, and I can say without a doubt that I learn very little. I prefer my plant introductions to be in person, I like to be able to touch, smell and when applicable taste the plant. Just as with humans plants have a first and a last name, the first part of the name is the genus and the second part the species. Common names I feel are just as important due to the fact that I find when I am asked questions, they usually go something like “Ever hear of cheeseweed, if yer chickens eat it it’ll make er eggs taste like cheese” really… Learn as much as you can about each plant you come in contact with, if nothing else Wikipedia the hell out of your garden, know what makes each plant tick.
Plant selection for permaculturists is really an art form that not only encompasses, but embraces biodiversity. Plants are the multi-tool in the permaculture world completing tasks such as attracting beneficials, repelling pests, soil remediation, soil stabilization, tillage, moisture control, living trellis, and as companions to one another often just simply enhancing flavor or improving one another’s health. An entire family of plants noted for their ability to fix nitrogen in the soil are the Legumes which include beans, peas, alfalfa and lupines as well as trees like locusts and redbuds.
I find that one of the most commonly mis-understood tools is the role of the legumes. Most legumes are sort of nitrogen hoarders in a way, fixing nitrogen for themselves and storing it for use inside the plant. Legumes don’t really “fix nitrogen in the soil” as much as they “fix nitrogen in the plant”, the green part of the plant is the key to nitrogen fixation. In order for the nitrogen to be fully utilized, the entire biomass of the plant needs to de-compose in place replacing the nitrogen into the soil. Another one of the commonly mis-understood ideas is that legumes fix nitrogen through out the entire life of the plant, this is simply just not true. Plants have changing nutrient needs as they progress through their life, plants use the most nitrogen during vegetative growth before flowering. Once a plant starts flowering, potassium requirements spike followed by phosphorus during fruiting. In order to maximize the nitrogen potential of legumes cut them before they go to seed and let the entire biomass of the plant break down in place.
Green manure is a cover crop grown to add organic matter and nutrients into the soil. Green manure is almost essential in a sustainable annual cropping system often being grown during the fallow period in winter and then tilled into the soil in the spring before flowering. Heres a quick list of plants used in green manure cover crops – clover, vetch, fava beans, mustard, buckwheat, lupin and alfalfa. Time energy and resources are required to grow and use these cover crops effectively, timing is everything and the window for planting is easily missed. Make sure that your planting dates allow enough time for your cover crop to get well enough established to over-winter.
Just in case you weren’t familiar with this next term I would like to introduce you to a guilty pleasure of mine called “fruit porn”. Oh you know you are into it, in fact, i’d be willing to bet your mailbox is filled with it during winter… Mine is! I sort of have a little problem with fruit porn, hoarding it, often finding old issues hidden in boxes for no good reason. All that I am going to say is be carefull, it is super easy to get “the bug” and order one of everything. I have seen this happen more than once and the end result is usually one or two absolutely perfect plants and a whole bunch of dead stuff. Instead pick one or two types of plants and get a bunch of one variety of each, this will allow you to familiarize yourself with that variety.
Urban lots are tricky in that they offer little space compared to a food forest or permaculture farm. When growing for more than just personal consumption you won’t be able to fill every square inch with every type of fruit tree, berry bush and vegetable you can get your hands on, instead pick a cultivar of apple and buy a few of them, and do the same with say blueberries and raspberries. This doesn’t mean you can’t plant a few specimen plants here and there and have a little fun with design. I am just trying to stress how nice it is to grow enough of one type of berry to be able to share or sell it.
I want to stress the importance of planting things other than food bearing plants and trees… I’m talking about bio-diversity here people, permaculturists work with EVERY facet of nature. Large trees create bird habitat and shade for the plants and people underneath them as well as something for the vines to climb on. The list of herbs that benefit other plants is absolutely enormous, common sage Salvia officinallis is one of my all time favorite herbs to use in the garden and landscape, when it blooms in early summer you can not get close to it because of the bees and is considered a companion to rosemary, cabbage, beans and carrots.
The idea of soil remediation or “phytoremediation” is nothing new, mankind has been using plants to repair soil for thousands of years. I always get a kick out of people referring to permaculture as “new” when in reality it is the cutting edge of a 10,000 year old idea… What we call organic, natural or sustainable was at one time simply called “FOOD”, it wasn’t until recent decades that we started having to specify the manner in which it was farmed. I have problems with the fact that foods are labeled organic as I feel the term is getting watered down as farmers test the limits of the rules, makes you wonder whats next… Morganic – Our veggies are morganic than the competition. Plants have been used to remove heavy metals and toxins from soil for years and a lot of research is currently being done on the subject.
Phytoremediation of leaded soils is a subject that is very near and dear to my heart, out of 10 lots soil tested last year here in Wilkinsburg I found only two that were within reasonable lead levels. Under 99 ppm is acceptable for lead levels in gardens growing veggies, we had samples test as high as 1558 ppm. Lead is commonly used in water and sewer pipes, roofing, cable coverings, paints, gasoline, insecticides, gold production, hair dyes, stained glass and photography to name a few. Lead is a moderately active metal that dissolves slowly in water and most cold acids, it does not react with oxygen in the air, and does not burn. Lead causes both immediate and long-term health effects and should be avoided at all costs. Lead is commonly remediated using indian mustard, ragweed, hemp dogbane and poplar trees which sequester the lead within its own biomass. Phytoremediation works as a multi-year tool for toxin extraction requiring a little planning, every effort helps though.
Here is just a small example of hyperaccumulators…
Arsenic – Sunflower or Chinese Brake ferns both store arsenic in their leaves.
Cadmium – Willow which is also an accumulator of zinc and copper, willow has a high transport capacity of heavy metals from root to shoot coupled with a huge amount of biomass production.
Cadmium and Zinc – Alpine Pennycress is a hyperaccumulator of these metals at levels that would be toxic to other plants, although the presence of copper will often inhibit growth.
Salts/salt tolerant – Barley and Sugar Beets are used for the extraction of sodium chloride to reclaim fields flooded with sea water.
Caesium 137 and Strontium 90 – Sunflowers were and still are being successfully used in the phytoremediation of the land around Chernobyl to absorb the radiation in the soil…
It is important to mention that phytoremediation is not an overnight solution to your soil woes but with some careful planning and consideration of time constraints, soil can almost always be remediated using plants… I could ramble on and on about plants so this may have to turn into a multi-part section of this series, we will see…
peace – chriscondello