During the textile manufacturing process, excess dyes are sometimes discharged as wastewater resulting in water pollution downstream. In recent years, particular attention has focused on water pollution in China resulting from indigo dyes used to create the distinctive blue color of denim blue jeans.
Some nanoscientists are looking at ways to help remove potentially harmful dyes chemicals from water.
Scientists at Colombia’s Universidad Industrial de Santander and Cornell University have come up with a cheap and simple process using natural fibers embedded with nano particles to quickly remove dye from water.
The research takes advantage of nano-sized cavities found in cellulose; plant fibers can be immersed in a solution of sodium permanganate and then treated with ultrasound causing manganese oxide molecules grow in the tiny cellulose cavities. The treated fibers are able to quickly break down and remove the dye from the water.
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Courtesy Mark RyanOver the past couple years, Science Buzz has posted several stories (here and here) about the humongous patches of garbage and plastic debris found floating in the world's oceans. It's a serious problem and one that should raise red flags for anyone concerned with the Earth's environment. But even more troubling is the recent news that plastic particles have now been found in all five of the Great Lakes lining the border of the USA and Canada. Unlike the large globs of plastic clogging areas of the ocean, the plastics polluting the Great Lakes are microscopic particles detectable only in a microscope. But they're no less disturbing.
A team of researchers led by Dr. Sherri “Sam” Mason, professor of chemistry at SUNY-Fredonia has been gathering water samples and reported finding high concentrations of plastic particles in the chain of freshwater lakes. One of the researchers involved is environmental chemist Lorena Rios-Mendoza from University of Wisconsin-Superior. Both she and Mason have studied the Great Trash Island (aka Trashlantis) in the Pacific Ocean but has now turned their attention to the Great Lakes.
Most of the plastic found in the water is visible only under a microscope, but has been found in all five of the Great Lakes, both in the water column, and in lake sediment. The amount of micro-plastic varies between lakes with Lake Erie - the shallowest and smallest by water volume - containing the largest ratio and Lake Superior - the largest and most voluminous - a much smaller ratio. But it doesn't matter; the point is that we're polluting some of our important sources of fresh water with plastic.
It's thought that cosmetics with could one of the sources, since the industry relies heavily on using micro-beads in its products. These tiny plastic particles used on our faces, skin, and teeth, eventually get washed off into the water supply where they're too small to get filtered out. But cosmetics certainly aren't the only source.
Courtesy tedxgp2Think of the ungodly amount of plastic material we use and discard every year. Surprisingly, only about five percent of the bags, bottles, cups, electronics, etc. get recycled; most plastic trash ends up in landfills where it slowly degrades and eventually finds its way into the world's favorite garbage dump: the oceans.
“We have no idea how long some of these plastics stay in the ocean, could be more than 40 years,” Rios-Mendoza said. She also worries if organic toxins in the water can attach themselves to the tiny plastic particles, and end up in the food chain. In this regard, Rios-Mendoza has been sampling Great Lake fish to see if such toxic particles are present in their guts.
It's important to remember that only 3 percent of the world's water is freshwater and the five Great Lakes - Superior, Huron, Michigan, Ontario, and Erie - together contain 20 percent of that freshwater. That's a large portion of a relatively scarce and essential life ingredient. Last fall, I posted an interesting graphic that illustrates nicely Earth's total water supply versus fresh water and puts things in perspective.
Courtesy Mark RyanRios-Mendoza and Mason have been collaborating with a research and education group called 5Gyres Institute that monitors and studies garbage patches found in five subtropical gyres in the world's oceans. Rio-Mendoza presented a preliminary study of their work on the Great Lakes at a recent meeting of the American Chemical Society. The team's future studies involve pinpointing the sources of plastic pollution and acquiring a better understanding of how plastics degrade in the environment.
"We all need to become aware of how much plastic we use in our lives and avoid using single-use products. Don’t buy water in plastic bottles or cosmetic products with micro beads. Bring re-usable bags to the store with you. Simple things like this make a big difference, but it’s also important to keep talking about this issue and raising awareness about how it affects the Great Lakes and the world’s oceans.” --- Dr. Sherri Mason“
By the way, here in Minnesota, and situated at the western tip of Lake Superior, the city of Duluth was recently proclaimed to have the best tasting drinking water in the state. By best-tasting, I'm assuming they mean it has no taste whatsoever since water is described as a colorless, tasteless liquid. Whatever the case, I always thought Duluth's drinking water was the best while growing up there (my grandparents lived in a Twin Cities' suburb and I never liked the taste of their softener-treated water).
In another water-related story, it's estimated that life on Earth can survive for at least another 1.75 billion years until we move out of the habitable zone and our oceans (and other water sources) will evaporate in the increased heat. So it's probably best that we take care of what water we have - it needs to sustain us for a long time.
Courtesy Birmingham Museums & Art Gallery An artist uses white cement treated with a light-sensitive photo-catalytic nano coating to make pollution pretty. As the cement is exposed to the air, the areas not protected by the nano coating begin to discolor, revealing a delightful design, as well as its nasty culprit.
It is estimated that two-thirds of sulfur dioxide (SO2) air pollution in North America comes from coal power plants. In a recent scientific article published in Geophysical Research Letters, a team of scientists have confirmed that SO2 levels in the vicinity of U.S. coal power plants have fallen by nearly 50% since 2005. .
Courtesy NASAThis finding, using satellite observations, confirms ground-based measurements of declining SO2 levels. In many parts of the world, ground-based monitoring does not exist or is not extensive; therefore, the Ozone Monitoring Instrument (OMI) on the Aura satellite could potentially measure levels of harmful emissions in regions of the world where reliable ground monitoring is unavailable..
Previously, space-based SO2 monitoring was limited to plumes from volcanic eruptions and detecting anthropogenic emissions from large source regions as in China. A new spatial filtration technique allows the detection of individual pollution sources in Canada and the U.S.
"What we’re seeing in these satellite observations represents a major environmental accomplishment," said Bryan Bloomer, an Environmental Protection Agency scientist familiar with the new satellite observations. "This is a huge success story for the EPA and the Clean Air Interstate Rule," he said.
We've written about freaky frogs on the Buzz Blog before, but some recent news may shed new light on our abnormal amphibians. Until recently, researchers thought that atrazine, an agricultural pesticide, was the sole cause of sexual deformities in frogs. Unfortunately, it's not so simple.
Courtesy Mike Ostrowski
An ecologist at Yale University, David Skelly, sought to test assumptions about atrazine by studying the frequencies of frog deformity in different land types--agricultural, suburban, urban, and forested. Skelly expected to find the highest rates of deformities in agricultural areas, which would be consistent with atrazine being the main cause. Curiously, he found the highest rates of deformity in urban and suburban areas--places we wouldn't expect to find much atrazine. So what's going on?
It turns out that what makes atrazine so dangerous is that it mimics estrogen and binds to estrogen receptors in frog cells. Because estrogen impacts sexual development and function, so too does atrazine. But atrazine isn't the only estrogen-mimicking compound out there--there's a whole class of chemicals that mimic estrogens, including those found in birth control pills and plastics (BPA). And these chemicals are found in droves in cities and surburban areas--they're flushed into the sewage, but aren't filtered out during water treatment.
So why do we care? Besides the fact that frogs are just awesome little creatures and important parts of their food webs, they have something in common with humans--estrogen receptors. The same chemicals that impact frogs can impact us. So how do we humans keep our sexual development and functioning intact?
Skelly had a great idea to filter this stuff out of the water at the treatment plant, so that it won't get into our bodies from drinking water. He also suggested that regulatory changes would help so that when new chemicals are developed, they're scrutinized for unintended side effects. And of course, we can make choices that reduce our exposure, such as by buying BPA-free plastics, or using stainless steel and glass containers. And of course, increased awareness is always a good idea.
Do you take extra steps to avoid things like BPA? What are they?
Courtesy ParanoidCheck this out, my little ducks: Scientists have genetically modified corn, so that it produces a deadly toxin. And that toxin is now appearing in waterways across the country.
But you should also check this out, my little chickpeas: That toxin (called “BT toxin”) is also naturally produced by the soil-dwelling bacteria Bacillus thuringiensis, which is already found sort of all over the place, including on leaves of plants. Also, all evidence indicates that while the toxin is deadly to certain insect species, it is utterly harmless to vertebrates (including people). Which is good, because most of the corn planted in this country has been engineered to produce the toxin in its leaves and stems,a nd that’s the way it’s been for years. And that may be good itself, because the bug killing toxin the plants produce can allow farmers to use a lot less synthetic, broad-spectrum pesticides (broad spectrum pesticides kill off lots of different bugs, instead of a specific few).
And consider this, my little Turkish delights: Those manufactured pesticides definitely run off fields into ground and surface water. See? So it seems like pointing out that the chemicals produced by the plants themselves also find their way into the water is a little bit of a “well, duh,” situation.
But science doesn’t run on “duhs,” my little Faberge eggs, it runs on empirically confirming or disproving explanations and ideas, whether or not they initially seem obvious. Because the toxin was contained in the leaves and stalks of the plants, it seemed less likely to get washed away in the same way sprayed-on pesticides usually are. But it got washed away nonetheless.
It got washed away, my little candy apples, but not in the same way—the toxin was present in streams 6 months after harvest, inside the floating detritus from cornfields. That is, the toxin was inside the bits of leaves and stems that had washed off cornfields, and into streams.
That doesn’t mean that the BT toxin is harmless, my little floral prints, but nor does it mean that it’s necessarily harmful. BT toxin appears to be a pretty environmentally safe pesticide on land, but that doesn’t say much about effects it could have in an aquatic ecosystem. It could be that the presence of BT toxin in the water is still much safer than the alternative (chemical pesticides), or it could be that it will have far reaching effects—Corn Belt streams end up in the Mississippi and Missouri River basins, and eventually in the Gulf of Mexico, after all.
So, my little rabbits’ feet, we should try not to be all, “well, duh,” or to get too freaked out about the whole situation. Before that happens, scientists will have to figure out what environmental effects the BT toxin has, and how those compare to other pesticide run-off, and how each might balance against our need for crops that haven’t been eaten by bugs.
Scientific American’s brief article on the presence of BT toxin in streams also brings up the issue of no-till farming. Scraps from corn fields ending up in streams is very common, apparently, but the SA article suggests that no-till farming might be increasing the amount of that kind of organic matter that end up in the water. No-till farming is a method of farming where the soil isn’t regularly plowed or turned over, and scraps from crops (crop residue) are left on the field after harvesting to increase soil quality. No-till can increase the amount of water in the soil and decrease erosion, but the remaining crop residue might end up in nearby streams to a greater extent.
If this is the case, my little supernovas, it makes me wonder if the crop residue from no-till fields is worse for the water than soil washed off of tilled fields (and whatever washed away with that soil).
I also wonder what becomes of the toxins in BT-producing crops when the crop residue is not left on the field. Because, of course, that stuff doesn’t just disappear. Crop residue can be burned on the field, or processed into ethanol fuel, burned in a power plant to generate electricity, or maybe dumped into the ocean. So, my little chitterlings, even without bringing our thirst for fuel and electricity into the mix, what happens to BT toxin in those scenarios? Probably nothing, for the most part, but, again, we don’t want to invest too much time in saying “duh.”
It’s all very complicated. But you knew that already, didn’t you, my little safety goggles?
Courtesy PxMaOn my way to the candy store last week, I ran into a very skinny young man with a clipboard. I mean, I didn’t really run into him—more like he called me over while I was trying to avoid eye contact. He was really skinny, though, and I thought maybe he needed help. See, I’m pretty skinny myself, so when I think someone might be too skinny, it could suggest a real problem. I thought I could at least direct him somewhere where he might buy a sandwich or something.
But, to my surprise, the young man had little to no interest in sandwiches. (I know! What?!) What he was interested in was my money, money I had been saving to spend on really important things, things like candy. The slender lad was fund-raising for an organization that’s lobbying against proposed mining in the Boundary Waters.
I felt like, “I don’t even have cable, and you want $30 a month? I’m looking out for Number 1 here, sir. Go buy yourself a sandwich.” wasn’t really an acceptable excuse for not giving away my credit card information on the sidewalk, so when I told him I’d “think about it” and ran away, what I meant was, “I’m going to think of a better excuse for next time we run into each other.” But I also promised him I’d look into the issue. (That wasn’t what he wanted, but whatevs.)
And I did look into the issue, at least a little bit.
The deal is that there’s a Minnesotan mining company partnered with a South American corporation that’s been exploring for metals near the Boundary Waters Canoe Area Wilderness. Their test pits have revealed that there may be huge deposits of copper, nickel, gold, platinum and palladium in the area, and they want to dig it up.
And that’s cool, except that bringing up the metal-bearing ore also brings up toxic heavy metals (like lead, arsenic, and manganese), as well as lots of sulfide rock, which can release sulfuric acid into the environment. These mining byproducts can be tricky to contain anywhere, but the proposed mines are located in the watershed of the Boundary Waters. That means that any acidic or metal-contaminated water that leaks from the mines would flow into the lakes of the Boundary Waters, poisoning them.
So that’s no good. The mine owners, however, counter that the rocks in the area are very solid, and so very little water would seep through them to contaminate the watershed. They also claim that the waste rock produced would actually have very little sulfur in it, and would not produce acid pollution.
Ok, that’s good. Except mining opponents point out that environmental assessments of similar proposed mines in the area have returned grim results for the watershed, despite the companies’ claims that the mining operations wouldn’t pollute. Also, other mines in the region, like the Dunka pit, have produced so much pollution that cleanup operations have spanned decades.
Hmm. So what, then? One (i.e., me) is inclined to think that we shouldn’t be screwing around with an area as beautiful as the Boundary Waters, and that if it means mining a little less, that’s cool. So does Skinny get to dip into my precious candy fund? Maybe!
Except… how about this: maybe we really do want those metals. Probably most of us who feel particularly protective over areas like the Boundary Waters also feel like our reliance on fossil fuels is harming the environment. Burning those depleting hydrocarbons produces vast quantities of atmospheric pollutants, and to see the environmental dangers involved in just digging up the fossil fuels, we need look no further than the oil spill in the Gulf of Mexico. So how do we wean ourselves off of fossil fuels? With cool technology to make our vehicles more efficient, or to make larger, more powerful batteries, or to take advantage of other fuel sources.
And what do we need for all of that equipment? A whole new set of natural resources which, as Minnesota Public Radio points out in their story on the mine controversy, includes copper, gold, platinum, and palladium, “metals that are used in everything from electric wires and computers to catalytic converters and rechargeable batteries.”
How might the consequences of the continued heavy use of fossil fuels eventually affect the Boundary Waters compared to mining in its watershed? Is it better to obtain these minerals in other parts of the world, so that it’s someone else’s problem? Are some environments more or less valuable than others? What if the mining takes place in a country with less-strict regulations for keeping a mine clean? And is there anything to the thought that, as fossil fuel users, we’re taking advantage of mining and drilling in other parts of the world, while we’re unwilling to let it happen in our backyard?
It’s probably not useful to divide the sides of the issue into either/or and good/bad. I want the Boundary Waters to be protected, and I’m against pollution-causing mining operations, but… it’s complicated.
Too complicated to figure out on my way to the candy store, anyway.
Any thoughts on this, folks? Negative environmental effects here… or there? Now or later? What do we really need? How should we get it? And from where? What are we willing to sacrifice for it? And, for that matter, what’s ours to sacrifice?
My mom just sent me an E-mail. Why's that worthy of a Buzz post? Well, it just so happens that she's on board the OSV Bold, the US Environmental Protection Agency's only ocean and coastal monitoring ship. (It's crawling along the coast of Maine right now.) From the boat, scientists are able to sample the water column, ocean bottom, and sea life to get a sense of how the ocean is being impacted by human activities, and how we can better manage what goes into it. If you're curious, you can follow the adventures of the OSV Bold on Twitter, or read the daily observations log. (There's a photo of Moms in the batch posted for day 4, but her face isn't visible. Just trust me: she's the beautiful on the Bold. Oh, and lest you think this is a completely frivolous and nepotistic post, check it: www.whitehouse.gov picked up the story, too.)
Courtesy steven.bussHere at Science Buzz, we sometimes have what might seem like a Through the Looking Glass attitude towards Earth Day and environmentalism. I, for one, litter filthy old cans all over my yard, comfortable in the knowledge that these cans will provide wonderful little shelters for the population of rats in my neighborhood. Sort of counter-intuitive, huh? Well check this out: after I get rats living in those cans, I’m going to use highly toxic chemicals to poison the little suckers in their homes. I will then plant sunflower seeds in my dead rat filled cans. So litter + poison + patience = a beautiful garden + delicious sunflower seeds.
Sophisticated environmentalism can be complicated like that.
It feels good though, doesn’t it? A little weird, but good.
Here’s another one (and this one comes from scientists who published in the journal Nature, not just from, you know, me):
Air pollution is fighting global warming!
Say what? We thought global warming was caused by air pollution.
Yes, but… think back to flowers growing from cans of dead rats. It’s like that, kind of.
See, yes, air pollution in the form of carbon dioxide (and other gases, but we’re dealing with CO2 here) is warming the planet. But CO2 isn’t the only junk we’re burping up into the atmosphere. Think about the grey brown haze you see over some big cities. Co2 is invisible, so what’s that stuff? Some of the chemicals we put into the atmosphere have the effect of absorbing sunlight, or reflecting it back into space. Some particles form the nucleus of water droplets in clouds, and cause the same amount of water in a cloud to be spread out among a much larger number of droplets, and more droplets cause light to be reflected and scattered more. It’s all part a phenomenon sometimes referred to as “global dimming”.
Some scientists believe that “global dimming” has had the effect of partially masking global warming; we aren’t as warm as we might otherwise be for the amount of greenhouse gasses in the atmosphere because a significant amount of solar energy has been prevented from reaching the Earth by other pollutants. So there’s that.
The Nature article, however, focuses on something else entirely. While many people might assume that plants have a harder time growing in our pollution-dimmed world, it turns out that they actually seem to grow better under a hazy blanket of pollution. The light-scattering effect of many air pollutants actually causes light to reach more plant leaves. So more photosynthesis is taking place under this diffused light than under direct sunlight. That means that plants are growing more, and growing plants suck up more carbon dioxide.
The scientists behind the study estimate that global dimming could be responsible for as much as a one quarter increase in plant productivity from 1960 to 1999, causing a 10% increase in the amount of carbon stored by the land.
This also means that as we have stricter air pollution controls, the rate of global warming probably won’t decrease as much as we’d have thought—there’d be less CO2 in the air, but because other pollutants would be reduced as well plants would be less productive, and suck up less of the CO2 that is released.