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  • Francisco Artigas- Meadowlands Environmental Research Institute

  • We have a legacy of contamination in the districtorganic pollution is very prevalent. We are coming

  • out of a cycle of 60, 70 years - I could go even further back - of industrialization.

  • I mean this is the quintessential, post-industrial landscape in New Jersey low lands. People

  • just dumped here.

  • Narrator Francisco Artigas is talking about the Kearney

  • (Carney) Marsh located in the Meadowlands of northern New Jersey.

  • Once a salt water marsh, it was drained and used as a land fill. Later, a fresh water

  • marsh was established on top of the dump. And while wildlife still remains here today,

  • Kearney Marsh faces other threats than those from below.

  • During rainy periods, sewage overflows into the swamp. Runoff from nearby landfills is

  • also a problem.

  • The result is a marsh laden with toxins. For Donna Fennel, this is a perfect place- for

  • she is a soil explorer.

  • Donna Fennell-Rutgers University A lot of people have heard about PCB’s.

  • That’s Polychlorinated Biphenyls. These are compounds that were produced as industrial

  • chemicals and used for electrical insulators. They were used in carbonless copy paper. Their

  • production was banned in the 1970’s after it became apparent that these things were

  • an environmental problem. PCBs are very hydrophobic so they like to stick to soil particles. Soil

  • particles are the recipients of many types of pollutants. Some of these soil particles

  • get pushed into aquatic systems and form the basis of the sediment that forms in the bottoms

  • of rivers, lakes, harbors and coastal areas.Organic matter contained in soil is sort of an attractant

  • for these more problematic pollutants like PCB’s and dioxins.

  • Narrator Today, Fennell and assistant Val Krumins are

  • going against convention. The standard method for eliminating such toxins

  • is to dredge, physically remove the polluted sediments from the aquatic environment. This

  • is not only costly, but the muck collected then needs to find a safe home so that the

  • toxins don’t spread further.But Donna and her Rutgers colleagues believe they have a

  • better idea.

  • Donna Fennell Our techniques are intended to work naturally

  • within the sediment. Were really focused on treating the pollutants where they are

  • We are looking at microorganisms that occur naturally in the sediment or which we

  • may introduce to the sediment to transform and detoxify these compounds. That way, we

  • can detoxify the sediment in place and the excavation or dredging, if it occurs later

  • as a normal course of management of aquatic sediments, would not result in a new distribution

  • of pollutants.

  • Narrator The microbes that the Rutgers staff inject

  • into the polluted sediments are tiny bacteria - ones that, in order to live, absorb chlorine

  • from toxins like PCBs.

  • Donna Fennell What these microorganisms do is they use the

  • chlorinated compounds as their oxygen. Theyre breathing chlorine, so to speak.

  • Narrator The marsh experiment has several steps. First,

  • a barrel is set down into the sediment to isolate it from the rest of the bottom. The

  • de-chlorinating microbes are then injected into the sediment. Then a second blue barrel

  • is fitted into the first. This allows the scientists to funnel in materials from the

  • boat. The last step is to cap off the embedded barrel with a gel-like clay seal.

  • Donna Fennel This capping idea is something that has been

  • used for some time for treating sediments. What we want to do is study how the microbial

  • process under the cap can be stimulated, and how it can work in conjunction with capping.

  • The loading is about 16.5 pounds per square foot.

  • Narrator Back on shore, the Rutgers team examines the

  • sample just brought in from the boat. CSREES helped fund this research along with a grant

  • from the Department of Defense.

  • Scientist- This stuff is really soggy.

  • Donna Fennell Finding that that organisms de-chlorinated

  • dioxins to me was a very incredible moment. I think the organic matter content was like

  • 40%. I believe we are at the point where knowing something about the microorganisms, we have

  • the chance to make a breakthrough so that biological treatment of sediments is going

  • to be possible.

  • Narrator With the samples safely preserved in liquid

  • hydrogen, the serious sediment is transferred back to Rutgers where the rigorous lab work

  • begins. It is here that Fennell is discovering the intricacies of the de-chlorinating microbes

  • used at Kearney Marsh.

  • Donna Fennell We put the sediments in the bottles. We amend

  • them with certain things to stimulate the bacterial de-chlorination of the PCB’s.

  • Were growing more bacteria, and we watch the fate of those PCB’s over time in our bottles.

  • It has only been in about the last five years that we know the identities of the microorganisms

  • - the bacteria - that are doing the de-chlorination of the PCB’s and dioxins. And we are just

  • beginning to look at the genetics that controls that process.

  • Only by using molecular DNA technologies can we have hope of detecting those microorganisms.

  • Extracting the DNA and using molecular markers that are specific for the bacteria that we

  • are interested in, we can pin point members that only make up an small percentage of that

  • population.

  • I have a 3 year old in my house. I am very concerned about the impact that environmental

  • pollutants have. We are starting to break down these barriers. What happens in sediments?

  • What can degrade or bio-degrade these pollutants?

  • Were developing technologies to deal with these legacy pollutants, and we can sort of

  • right the wrongs from that done in the past. It is recovering our environmental legacy

  • and our heritage and making that a resource for future generations.

Francisco Artigas- Meadowlands Environmental Research Institute


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B2 中高級

嚴重沉積物 (Serious Sediment)

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    QAM Chen 發佈於 2021 年 01 月 14 日