Goodbye California

It was late Friday afternoon. With the working week finished, my roommates and I were relaxing on our couch at the Cal Poly Cerro Vista apartments with the door open, watching the sunset and taking turns strumming our favorite chords on the ukulele.  We were startled by a yelp and then frantic footsteps as Noelle, one of our REU peers, appeared in our doorway to say, “Come outside!  You have to see this!”  In our bare feet, we hurried to the back parking lot to see something black, furry, and the size of a hand crawling across the street.

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Meet Terry the tarantula, born and raised on the sunny hills of San Luis Obispo, California.

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Yea, to my surprise and delight, tarantulas exist here.  When I was little and all of my friends wanted dolphins and ponies as pets, I actually wanted a tarantula.  Too bad I couldn’t take him home!

So I’ve just posted my final tidbit on why California is such a cool and diverse state.  To wrap up the research I was doing on native California plants and their ability to translocate contaminants from the soil, I gave a presentation on the phytoremediation results I found.  It turns out that the plants were mostly sequestering contaminants from the soil rather than volatilizing them, which was the assumed outcome.  This is my professor Dr. Yarrow Nelson, me, the research poster I made, and the graduate student I worked with, Matt Poltorak:

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My experiences with research this summer showed me that I want to go on to graduate school.  I’m so happy that I received this opportunity to do an REU from the National Science Foundation and Cal Poly because it was really helpful in determining what focus of environmental engineering I like and want to pursue in the future.  I came out of this program with specialized knowledge that I would not have learned in a classroom, and am very grateful for that.  To all of you engineering or science majors, I highly encourage you to apply for one of these NSF REU programs.  I’m so happy that I did!

 

 


Some Data and Muir Woods

This weekend we took a road trip up the 101 (yes, that’s the highway quoted in the song California by Phantom Planet) to the San Francisco Bay Area where the Redwood trees grow.  We found ourselves walking through Muir Woods, gazing up at these 200 foot trees the writer and conservationist John Muir wrote poems about a hundred years ago.  He’s the one who said,”When one tugs at a single thing in nature, he finds it attached to the rest of the world.”  How right he is!

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Fun fact: some of these redwoods have been standing for a thousand years and are pretty fire resistant thanks to their moist bark.

We also came across a sign indicating that the surrounding space is a “First Amendment Area”.  This must be where groups can stand to petition for their cause.  From my previous experience as a petitioner for the Food & Water Watch, I can say it would be nice if parks everywhere set aside a place like this for petitioners and speakers!  California and especially the Bay Area seem to be very forward-thinking compared to the rest of the United States, so I wasn’t too surprised to see a cool sign like this.

Our drive home on Highway 1 was breathtaking, both because of the beautiful scenery and the fact that our car could fall off a cliff if the driver tried to appreciate the view with the rest of us.

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The picture on the right is a similar view off of California Highway 1 after the clouds rolled in.  You literally cannot tell how high up you are and feel like you’re floating in the sky.

Back on the ground, there have been some discoveries made with the phytoremediation plants.  The three native California plants I have been working with–Coyote Brush, Mulefat, and Purple Needlegrass–were tested to see which chemicals they were emitting and if these chemicals happened to be the organic contaminants from the soil they were planted in or not.  It turns out, my method of capturing volatilized chemicals worked, because the gas chromatogram showed peaks for molecules that plants are known to emit!  Of these are stearic and oleic acid, which are fatty acids, and D-Limonine, an essential oil.  This is what one of my chromatograms looked like.  Each peak indicates a chemical that was essentially volatilized by the plant.Sorbent In

And this is what the computer tells you when you click on a peak:

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To me, it’s so exciting to be able to determine what chemicals an unknown sample consists of.  All you have to do is run it through the GC-MS and voila, the database lists all of the possibilities of what the chemical could be.  The crazy looking molecule pictured above is Stigmastan-3,5-diene, an antimicrobial compound found in tree roots and emitted by the plants I was testing!

Though none of the organic contaminants were captured, establishing a working system for determining what the plants give off was a necessary step.  Next, some independent variables will be changed in order to increase the likelihood of capturing a contaminant from the soil that the plants are potentially phytovolatilizing.


SLO Moving in San Luis Obispo

The beautiful weather here is a blessing and a curse.  How do you expect me to accomplish anything inside when it looks like this every day?

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Poly Canyon

Yes, this is the paradise that’s been my home for two months, and this valley is a ten minute walk from my apartment.

The standard for being productive in San Luis Obispo, which the locals refer to as “SLO”, is quite different than in Philadelphia.  If you conquer the temptation to frolic outdoors in the sunlight and instead stay seated at your desk for half the day, you were productive.  So, in order to accomplish something today (Friday), I took on a vampire’s mentality and found a dark cubicle in the library away from all windows and sunlight.  I lasted two hours.  Thankfully, the plants in the greenhouse needed watering, so I found myself in the bright outdoors, breathing the fresh air once again.  Speaking of fresh air, the green fungus on top of the rocks pictured below is lichen.  This microorganism thrives in good air quality, which is why it’s growing on practically every tree here.

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Lichen growing on top of rocks at the peak of Poly Mountain

Enough about nature, let’s talk about contaminants.  If you haven’t read my previous posts, I’m basically studying whether native California plants translocate chemicals in contaminated soil through their roots, stems, and into the air as a gas.  This is known as phytovolatilization.  To capture any volatile chemical the plant is emitting, we secured an inert bag to the jar holding the plant and pump air through it into an activated carbon sorbent tube.  Inert material is material that will not react or alter any chemicals that encounter it.  Everything that the air from the plant headspace encounters must be inert so we know that the chemicals we find after analysis aren’t products of reactions that happened with the bag or tube.

How do I see what chemicals the activated carbon is catching? First I use a solvent, methylene chloride, to extract the activated carbon.  Okay well first I put on the massive solvent gloves to prevent any spills from leaking into my skin.  The captured organic contaminants adsorbed to the activated carbon should be more soluble in the methylene chloride and therefore detach from the carbon granules.  Next, I sonicate the mixture.  A sonicator uses high frequency noise to break the carbon granules into really small pieces.  This ensures that all chemicals sorbed to it get dissolved into the solvent.  Then the solution goes through some filtration and finally into the gas chromatograph, pictured below:

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GC-MS in Environmental Protection Engineering Lab @ Cal Poly

A gas chromatograph is basically an oven with thin hollow tubing on the inside, called a capillary column, that a gas carries your unknown sample through.  The inside of the capillary column is coated, usually with silica, and the carrier gas in my case is helium. Depending on the mass of each unknown chemical and its attraction to the capillary column, each chemical will reach the detector at a different time, indicated by a graph with peaks at different times.  Next, the mass spectrometer basically shoots electrons at each molecule, breaking them apart.  The fragments a molecule breaks into are basically its finger prints, because it will break into those fragments every time.  Using these two machines and the database of chemicals, I can determine which unknown chemicals were in my sample.  Since this sample came from air that the plant was transpiring in, ideally the chemicals it volatilized will be captured and discovered.  It’s pretty amazing that we have the technology to do this!


Chelating Agents and Starfish

The phytoremediation research that I’m doing here at Cal Poly requires a bit of creativity.  To give some background before I delve into the interesting tests we are running, phytoremediation is a form of environmental remediation that uses plants to clean up chemical contaminants in the soil.  I am working with three native California plants–coyote brush, mulefat, and purple needlegrass–to determine their ability to take up chemicals in the contaminated soil.

Here is a summary of the organic contaminants that the soil contains:

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  • Polychlorinated biphenyls (PCBs), which are a man-made chemical found in transformer fluid and banned for use by U.S. Congress in 1979

Dioxin (2,3,7,8_TCDD)

  • Chlorinated dioxins, which are produced from smelting and also naturally from forest fires and volcanoes

Naphthalene

  • Polycyclic aromatic hydrocarbons (PAHs) and other petroleum hydrocarbons, which are found in crude oil

There’s also a plethora of metals in the soil, some of which are dangerous…like mercury.  What I am going to explain in this post is how we plan to help the plants extract mercury from the soil they’re planted in.

The mercury in the soil is in Hg(II) form.  Basically, Hg(II) is taken into the plant by its roots and travels through the stems to its foliage.  During this process, Hg(II) is reduced to Hg(0) by mechanisms in the plant that are still being researched.  Once the Hg(0) reaches the foliage, it is released into the air as a gas via the stomata.  The stomata are essentially holes in the plant’s leaves that open and close depending on the pressure differential from the moisture in the air.

The beauty of mother nature’s setup is this: Hg(0) is less likely to be harmful to people and in the environment than Hg(II).  Because Hg(II) can more easily form organic mercury compounds, which are the most dangerous, it is better that mercury be in the Hg(0) form and out of the soil, which is teeming with organic molecules that have Hg(II) binding potential.

So, to recap, we are researching to determine which of the three plants, if any, have this potential to uptake mercury from the soil into their roots and volatilize it as a way less-harmful gas into the air.

Next is the fun part.  We decided to add a chelating agent, EDTA, to the soil to increase the plant uptake.   Ethylenediaminetetraacetic acid (EDTA) is an organic molecule that forms multiple bonds with an ion, encapsulating it.  It’s like putting a wrapper around a sticky piece of candy so that it won’t get stuck in your pocket.  The wrapper is the chelating agent, the sticky piece of candy is the ion, and the surroundings are the soil.  Because contaminants adsorb, or “stick”, to the soil, they need help detaching from it.  Once the chemicals are not adsorbed to the soil, they are more easily guided through the plant root cells. Below is a picture of the chelating agent (clear) that we added to the soil:

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So far, the plants that received a dose have started to get brown leaves and die.  This could be because the EDTA did what we wanted it to and increased the sequestration of Hg in the roots, stems, and foliage.  However, it’s likely that EDTA prevented the plant from receiving other vital metals that it naturally uptakes from the soil.

In my next post I will explain the process of analyzing what chemicals the plants volatilize.

On another note, this weekend the other REU students and I went to Montana De Oro, home to giant sand dunes and starfish!

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I have never seen a real-life starfish, so this was exciting!  We spent the afternoon walking on the rocks and finding sea anemones.  I noticed a black, sticky tar that covered most of the rocks and think this may be from oil pollution in the ocean.  It was nice to see that the rest of the beach and park was clean though!


Horizons End

I have greatly enjoyed my time here in Abu Dhabi. There are definitely many new buildings and opportunities arising out of this desert, changing and creating new horizons. It is amazing how much the cities of Dubai and Abu Dhabi have grown in just a few decades of time. From small desert outposts to growing international communities. There are people working and living in Abu Dhabi from every known corner of the world. It has been wonderful to spend time learning from and talking to people from other places and other cultures. As much as I have enjoyed seeing and learning about the architecture and structures in the UAE, it is the people I met here that I will miss the most.

Kalifa Port End

Although figuratively for me since, it is also nearing the end of my trip here to the UAE. This is the end of Abu Dhabi Island. Literally, these rocks prevent the sand from eroding away at the end of the Khalifa Port. They also provide a beautiful view for sitting down and looking out at the Arabian Gulf.

As it is with most journeys then end of one, is also the beginning of another. There will be more horizons waiting back in the USA.


UAE Pavilion from Shanghai Expo 2010

The UAE was the first gulf nation to present a pavilion at Venis Biennale. This design built in Shanghai in 2010 rises and falls like a sand dune oriented along the wind. The passive solar space was designed by Foster + Partners. After the Expo the pavilion was moved to a new development and cultural center being built on Saadiyat Island in Abu Dhabi. When construction finishes, this district will including museums such as the Zayed National Museum, Louvre Abu Dhabi, and Guggenheim Abu Dhabi. Although the interior of the pavilion is not open to visitors, except during an annual local arts fair, I was able to see the exterior of this wonderful design.
For more info on the pavilion: http://uaepavilion.org/uaepav/about-national-pavilion-of-the-uae/

http://www.fosterandpartners.com/news/archive/2009/04/the-uae-pavilion-at-shanghai-expo-2010-breaks-ground/

National Pavilion UAE
For information and plans on other Saadiyat Island structures:

http://www.saadiyat.ae/en/project-update.html


Beware of Mountain Lions

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The sunset from Poly Mountain in San Luis Obispo, Ca.

To everybody who plans on visiting California…WARNING: mountain lions, wild turkeys, rattle snakes, and bears roam these seemingly innocuous golden hills and luscious valleys.  How these mountains paralyze you with their captivating beauty while simultaneously feeding you with spontaneity and adrenaline!  They just plead for you to frolic through them like a baby deer without a worry.  In a place like this, it’s hard to think that anything could hurt you.  My mom always nagged me about “being aware of my surroundings” when I was growing up, and clearly I never listened…

My favorite way to start my day here at Cal Poly State University in San Luis Obispo, Ca is to run through the valley trails like in the picture above.  One morning this week, on the trail about 50 feet in front of me, I saw an oversized gray cat trotting along.  I thought, “Oh, that must be a mountain lion cub or something! Neat!” and proceeded to run past the brush that it jumped into, wondering if its mama was in there.  It wasn’t until later that day, when I mentioned the baby mountain lion siting, that my roommates made me realize how dumb I had been.  They said, “Didn’t you read the warning sign at the trailhead!?” Obviously not, because the last thing you are supposed to do when you see a mountain lion is run, since it may mistake you as prey.  You’re supposed to a) turn around or b) make a lot of noise and seem threatening like a predator.  I’m pretty lucky that mama lion didn’t decide to chase me for running towards her cub.  In Delaware County Pennsylvania, when we hike in the woods, all we have to worry about are deer ticks! 

Moral of the story, always be aware of your surroundings and take the time to read signs, especially when you’re some place new.   


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