Do those compostable, corn-based plastic products really biodegrade?
In a laboratory, sure. In your backyard compost pile? Not so fast, buster.
(Image: Corn-based plastic cup after five months in a backyard composter.)
Our experiment, with a corn-based cup marked “compostable” in green ink, has this preliminary result after five months in an Earth Machine composter: Not yet.
And it's not just me. I checked with some of the other compost-oriented folks on Kaua'i.
“The cups compost slowly in my pile. It is better to cut them in small pieces,” said Gordon LaBedz, chair of Zero Waste Kaua'i. “The forks and spoons hardly break down at all. At least they are not petroleum based.”
Katie Paul of Mālama Kaua'i said shredding is key. One presumes that's because it increases the surface area.
My compostable plastic cup, acquired at an earth-friendly event that touted zero waste, had cracked after five months in my compost pile, but it hadn't composted. Not at all.
A lot of folks are spending a lot of time feeling good about themselves for using compostable products at mass events. Is this stuff really as eco-friendly as everyone says?
And if it didn't compost in half a year in my Earth Machine, how does it compost?
It appears that the composting of compostable plastics requires fairly specific conditions. They need adequate moisture, high temperature, and they also need the microbes in compost to do a complete job.
In J.A. Brydson's 1999 book, “Plastics Materials,” Brydson says that biodegradables first require the moisture to break up the larger molecules in the plastic, and then the various life forms in compost to further break it down to the primary components of carbon dioxide and water.
High temperatures are also needed—and although elevated temperatures are readily achievable in a well-managed compost pile, the question is whether they're getting high enough.
I found detailed instructions at the site of a firm called NatureWorks PLA, a Cargill company. (http://www.natureworksllc.com/media/files/distributor_flyer_12_5_05rv.pdf)
The site says its plastic will break down in just 47 days into earth-friendly carbon dioxide, water and humus (decayed vegetable matter).
What's it need to have that happen? “Composting PLA requires approximately 140ºF and humidity between 80% and 90% for extended periods of time.”
The firm BASF has a compostable plastic it calls Ecoflex. In a laboratory, using one heat-loving compost-derived organism, they were able to obtain 99.9 percent biodegrading in 22 days at 130 degrees Fahrenheit.
And in an environmental assessment for the BASF product, there are these words: “While Ecoflex is compostable, this is not expected to be a significant means of disposal in the United States because composting is not currently a significant waste disposal method in this country.”
That, and the difficulty of composting the “compostable” plastics leads to this suggestion:
“I guess I just want to remind you to use reusable dishes and linens as much as possible. Please!” said Pam Lightfoot, emailing from Maine.
So what happened with our experiment with a compostable plastic cup?
The experiment took place through a dry summer, and other than kitchen scraps, little additional moisture was provided to the Earth Machine. It was in fact composting other organic materials, and providing good soil amendment, but did so slowly. Probably, it didn't have the requisite moisture or the requisite temperature to accomplish the breakdown of the plastic.
This experiment will continue, and perhaps the wet winter will assist the degradation. The point of this particular experiment is not to create perfect laboratory conditions—the plastic companies have done that and their results seem clear. The point is to determine whether this stuff breaks down in the standard backyard operation.
I turned to an expert on the topic, John Harder, who spent his career in solid waste management, and is now working with Zero Waste Kaua'i. He has a large biodegradable plastic composting experiment underway.
I turn it regularly, I try to balance the nitrogen, but I still only get about 120 degrees. The cups are turning milky white but they're not disappearing. You need to get it to 140 degrees for six to eight weeks and you really only get that in an active commercial operation,” he said.
One problem with leaving cups whole is that they tend to trap air, and the microbes can't get at the whole cup: “If you shred them with the green waste (in a composting operation), you get a lot of surface area.”
Harder said that since you can't have cups breaking down while you're drinking from them, they need to be quite durable. That makes their breakdown a little more challenging—but still possible.
“If you grind them up and get the temperatures up, they will break down,” Harder said.
©2008 Jan TenBruggencate
Saturday, September 27, 2008
Posted by Jan T at 9:39 AM
Friday, September 26, 2008
Much of native Hawaiian vegetation is understory vegetation, growing under canopies of 'ōhi'a and koa—but in restoring natives, will just any canopy species do?
Perhaps not, according to a study performed by Rebecca Ostertag at the University of Hawai'i at Hilo, and Christian Giardina and Susan Cordell, if of the USDA's Institute of Pacific Islands Forestry in Hilo. Their work was published in the journal Restoration Ecology under the title, “Understory colonization of eucalyptus plantations in Hawaii in relation to light and nutrient levels.”
They studied what was growing under a seven-year-old forest of Eucalptus saligna trees on former agricultural land. The forest had sections that were fertilized and others that were unfertilized, and herbicides had not been used for at least five years.
Saligna is also known as Sydney bluegum, and is a fast-growing, straight-grained tree popular for forestry applications.
The understory vegetation turned out to be heaviest in areas where more light was able to get to the surface. But generally, it contained mostly alien plants—not natives.
The most common tree under the fast-growing eucalypts was a weedy tree, Citharexylum caudatum, also known as fiddlewood or juniper berry. It is a tree often planted along streets, but which becomes a dangerous weed in the Hawaiian wild.
The researchers further studied a series of other plantations containing several different Eucalyptus species. Including E. saligna, E. grandis (rose gum), E. cloeziana (Gympie Messmate or cloeziana gum), and E. microcorys (Australian tallowwood).
“Again, very few native species were present in any of the stands, indicating that within certain landscapes and for native species with certain life history traits, exotic plantations may be ineffective nursery ecosystems for the regeneration of native species,” they wrote.
Some eucalyptus species are also known to contain growth inhibitors, which can limit the ability of other plants to colonize the ground under eucalypt plantings.
©2008 Jan TenBruggencate
Wednesday, September 17, 2008
I looked out across the ocean east of Kaua'i yesterday, and saw O'ahu.
It sat there on the horizon, a dark hump in the distance, with a low shelf off to the right side. Not clear enough to pick out gullies from ridges, but clear enough to know it was real.
(This is the scene yesterday morning looking toward O'ahu from Nawiliwili on Kaua'i. With the naked eye, the shape of the island was visible, but the camera was unable to resolve the island's outline.)
This isn't unheard of. Kaua'i residents who live in Kalaheo and Wailua Homesteads report that on special days, they sometimes spot the island from their highland vantages.
And other folks say they'll spot it from time to time even from Lihu'e.
But being able to see O'ahu from Kaua'i or vice-versa is rare.
I've never seen a photo of one island taken from the other, and even on this day, it was still hazy enough that while my eye could pick the shape of the island out, my camera could not.
O'ahu folks know how hazy Moloka'i can be in the distance, across the Kaiwi Channel. Well, the Ka'ie'iewaho Channel more than twice as wide as the Kaiwi. Sixty miles from closest point to closest point.
On a normal day, there's nothing at all sitting on the horizon.
I'm assuming the island was visible because the air was unusually clear. There had been a couple of days of calm, which let the ocean spray settle down. And the trades had just returned, lightly, to push the vog away.
As the wind picked up on the ocean, the island grew more faint, and by midday it was gone again.
I have sailed between the islands, and normally have been able to pick Kaua'i out on a voyage from O'ahu at a range of 40 miles to about mid-channel, depending on ocean conditions.
For those cogitating on the issue, viewing these islands does not require any special bending of light. The highest point on the Wai'anae range is near 4,000 feet and Kaua'i is more than 5,000 feet high.
Even from sea level, the curvature of the Earth would obscure the bottom half of the view, but leave a significant piece of the island visible.
Smaller islands are often close enough to be viewed before they actually rise above the horizon.
From a sailing vessel, the island of Nihoa, west of Kaua'i, first appears as a pair of nubs above the horizon—the tops of its twin peaks. Then, as you sail closer, the saddle between them rises. And still closer, the island rises to look like a giant molar, with vertical sides, peaks on both extremities, and the saddle between.
© 2008 Jan W. TenBruggencate
Monday, September 15, 2008
Perhaps black holes can only get so big, and no bigger.
But so big, is really, really big.
(Image: Ultra-massive black holes like the one shown seem to have a limit in the mass they can attain—but an impressive limit. (Credit: NASA, ESA, and The Hubble Heritage Team.)
The maximum black hole size seems to be around ten billion times the mass of our sun. In another way of looking at it, perhaps black holes can get no bigger than one percent of the mass of the galaxies they inhabit.
Astronomer physicists from the University of Hawai'i and Yale suggest that while they may not technically go on diets, black holes at least stop increasing their size once they become so grotesquely large.
Black holes were once in the realm of science fiction, but they're now accepted in physics. They are intensely powerful features whose gravity is so great that it sucks in everything nearby. Black holes grow in size like people do—by eating.
But there seems to be a point at which they simply can't do it any more. It seems that when black holes approach a mass of 10 billion times that of our sun, they stop, according to Ezequiel Treister, a Chandra postdoctoral fellow at the University of Hawai'i's Institute for Astronomy and Priyamvada Natarajan, an associate professor of astronomy and physics at Yale University.
Their study was published in Monthly Notices of the Royal Astronomical Society (MNRAS).
The scientists used both optical and X-ray studies of black holes to show that, at some point, black holes continue to exist, but stop growing.
It's not clear why. Natarajan suggests that the radiation from the supermassive black hole is so intense that it destroys its own food sources.
No matter where you look in the universe, their appetite seems to abate.
"They shut off at every epoch in the universe," Natarajan said.
When you look out into the universe, you also look back in time. The farther away things are, the longer it's been since what you're looking at actually happened. The researchers found that there seemed to be limits in black hole size, no matter how long ago they existed—no matter how far back in time you look.
“The only way to match the observations at early times with late times is by having black holes stunt their own growth,” Treister said in a prepared statement.
© 2008 Jan W. TenBruggencate
Friday, September 12, 2008
How do you prevent renewable energy from taking hold in Hawai'i?
The answer keeps coming home, and did again this week at the 2008 Kaua'i Renewable Energy Conference.
You want renewables to fail? Have the renewable advocates fight among themselves.
At least some of them are doing it in Hawai'i.
You've got some hydroelectric supporters saying they're way more steady than wind, which also kills birds.
And solar folks saying hydro is hazardous to 'o'opu stocks.
And ocean thermal energy folks saying solar is iffy because of clouds, and, well, nightfall.
And wind, hydro and solar folks saying ocean technologies are really still experimental.
And many of those folks saying biofuels have all sorts of environmental issues; and biofuels folks saying that at least their fuels can be used in existing engines—whether transportation or powerplant—and they provide fuel that's available where and when you need it.
And the energy efficiency folks saying theirs should be the first initiative, before all those other technologies are put into play.
It's an endless circular game guaranteed to keep fossil-fuel power at the forefront, and carbon dioxide pumping into the atmosphere.
Maurice Kaya, a strategic energy and management consultant and the former state Chief Technology Officer, argued that there's no time for all this.
“There is too much cost and way too much risk in the status quo,” Kaya told the energy conference. “We are well beyond the time when we must act.”
Kaya argued that it is time for the entire community to insist that renewable energy assets be developed and to insist that policy makers take the issue of moving away from fossil fuel energy seriously.
Kaya co-convened the Kaua'i energy conference with William Parks Jr., deputy assistant secretary of the U.S. Department of Energy's Office of Electricity Delivery and Energy Reliability.
Parks said that one of the things needed immediately is to modernize the power grids in Hawai'i, so that they can handle the new kinds of often-intermittent renewable power.
There is value in moving quickly, and there are large costs to delays, he said.
In the words of former state consumer advocate Bill Milks: “I believe we have a crisis.”
© 2008 Jan W. TenBruggencate
Wednesday, September 10, 2008
Gay & Robinson, one of the two remaining sugar companies in Hawai'i, will go out of the sugar business when it finishes grinding the sugar now in the ground.
That should keep the company—which has been in cane for 116 years—making sugar through about August 2010. After that, the only remaining Hawai'i plantation producing sugar will be Maui's HC&S.
But this doesn't mean the Kaua'i community will be cane-free or that jobs will be lost.
Gay & Robinson (G&R) plans to lease much of its sugar acreage as well as its mill site and equipment to Pacific West Energy LLC, which will grow sugar cane to produce energy and ethanol.
The switch from sugar to energy will have a dramatic impact on the island's energy picture.
Pacific West Energy's Will Maloney told Raising Islands that his plant is expected to be able to deliver up to 20 megawatts of energy to the power grid.
Since the maximum demand for Kaua'i Island Utility Cooperative is slightly short of 80 megawatts, that plant could at its peak produce a quarter of the island's maximum electricity demand. That should help the utility move a huge step away from Kaua'i's roughly 90 percent dependence on fossil fuels for electricity.
Additionally, G&R plans to build a new hydroelectric plant to capture the energy in water now flowing through an existing hydroelectric plant that is at the 1200-foot elevation. The water running it will be piped downhill to a new 5 to 10 megawatt power plant to be situated at the 200-foot elevation. It will have variable actual production, depending on rainfall, said G&R President Alan Kennett.
The switch from sugar to energy should have no long-term negative impact on the job market. Maloney said Pacific West Energy will need all the current G&R employees, plus more.
In a press release, G&R said: “The company will continue to honor its contractual obligations to its workers, including current employees as well as retirees.” The firm plans a meeting shortly with the ILWU—the union that represents sugar workers—to discuss the transition.
Maloney said that depending on successfully completing its negotiations with G&R, Pacific West Energy next year should begin planting G&R fields with its own cane as G&R harvests those fields.
The company also expects to expand Kaua'i sugar acreage. G&R has about 7,500 acres in cane. Maloney said his firm will need about 15,000 acres. While he did not identify where that additional acreage would come from, there is extensive former sugar cane land lying fallow around the G&R plantation. Mainly, it is state-owned land previously farmed by two now-defunct plantations: Kekaha Sugar Co. and Olokele Sugar Co.
Kennett said that not all G&R's sugar lands will be leased to Pacific West Energy. Some will be leased to other agricultural ventures.
Maloney said the cane grown for energy will generally be harvested when it is one year old, compared to the two-year cycle currently used by the sugar firm. As a result, it is possible that during late 2010, G&R and Pacific West Energy could be harvesting at the same time—G&R for sugar and Pacific West Energy for ethanol.
Using existing fermentation technologies, Pacific West Energy expects to produce up to 15 million gallons of ethanol annually.
Kennett said the G&R has opted to leave the sugar industry because of significant financial losses.
In a speech this week to an energy conference on Kaua'i, Kennett said the sugar company faces serious increases in all its costs—for fuel, fertilizer, steel and virtually everything else—while sugar prices remain at about 18 cents a point—the same amount the company got two decades ago.
Said Kennett: “Gay & Robinson has been at the forefront of the sugar indusry since its founding in 1892, and is only one of two remaining sugar producing companies in the Hawaiian Islands. We are now moving forward and intend to be at the forefront of a new era as a renewable energy producer helping to reduce Kaua'i's imports of fossil fuels for our energy needs.”
© 2008 Jan W. TenBruggencate
Friday, September 5, 2008
Researchers aboard the University of Hawai'i's research vessel Kilo Moana just completed a 12-day passage from Honolulu to California, looking for drifting plastic.
They weren't disappointed—or were, depending on how you look at it.
(Image: A sampling of plastic particles collected by the R/V Kilo Moana during its crossing of the North Pacific Subtropical Gyre. Credit: Lucy Marcus)
The crew conducted 14 trawls during its passage, and collected hundreds of bits of plastic on each one. Some were as small as pinheads; others as big as volleyballs, the research team reported.
The fact of plastic in vast quantities on the ocean isn't news. It's been a research subject for the Algalita Marine Research Foundation, whose raft built of trash recently sailed from California to Hawai'i to help call attention to the project. The raft's name is “Junk.” For lots of information on the web, search for trash, raft and algalita.
The Kilo Moana trip's mission was called SUPER, for Survey of Underwater Plastic and Ecosystem Response.
Its goal was to help determine the impact of all that plastic on the natural environment.
We know some of the impacts. Birds eat it and feed it to their chicks, which can die from bellies bursting full of undigestible plastic bits. Turtles appear to feed on plastic bags that look like jellyfish in the water. Animals like seals get trapped and drowned in plastic netting.
But are there other impacts, either positive or negative.
Says the program: “We will use these samples to characterize the diversity and productivity of plastic-associated microbial communities, while water samples that were collected at each station will be analyzed to describe regional biogeochemistry.”
According to the website, cmore.soest.hawaii.edu/cruises/super/index.htm, among the questions SUPER is looking into are these:
Do plastic bits provide habitat for microbes; what kinds of microbes are found around them; what's the role of plastic waste in bacterial production rates; how does the plastic affect the movement of nutrients in the ocean; and how does it impact movement of light through the water?
For more information on related issues, see cmore.soest.hawaii.edu/index.htm.
The previous RaisingIslands post on this topic is at raisingislands.blogspot.com/2008/08/plastic-marine-debris-in-spotlight.html.
A post on small boat voyagers, including Junk, is at raisingislands.blogspot.com/2008/06/unique-ocean-voyagers-at-sea-in-small.html. Since that post, all three of the voyagers mentioned have made it safely to their initial destinations.
© 2008 Jan W. TenBruggencate
When Kaua'i County opened up a bike path on the east side of the island, the shocking thing was how many people immediately began using it for walking.
It seemed there was a pent-up demand for a safe walking spot—and increasingly, that's being viewed by scientific work as a good idea.
Hawai'i residents seem to get this. Hawai'i already has the second-lowest obesity rate in the United States (see healthyamericans.org), which may be linked to having one of the lowest adult inactivity rates in the country. (healthyamericans.org/state/index.php?StateID=HI)
But obesity isn't all of it, and the benefits of exercise are not even just about physical health.
A stunning new just-published Australian study shows that adults over 50 whose mental capacity is declining can reverse that process with a comparatively moderate exercise program.
Just go walking.
You might readily assume that keeping healthy would delay the decline in physical and mental well-being, but the concept of turning your forgetfulness around is remarkable.
The study, as reported by Science Daily, involves work written up by Nicola Lautenschlager and associates in the Journal of the American Medical Association. The title: “Effect of Physical Activity on Cognitive Function in Older Adults at Risk for Alzheimer Disease.”
Lautenschlager is chair of the Old Age Psychiatry program at Australia's University of Melbourne.
They divided up 170 people who reported memory problems that were still short of being categorized as dementia.
Half of them didn't do anything different in their lives. The other half joined a 24-week exercise program that aimed at three 50-minute walks each week—or similar exercise. It ended up that the second group was doing about 20 minutes a day more exercise than the other group.
At the end of the study, the exercising group did better on mental tests and had better recall, as well as lower ratings on a Clinical Dementia Rating system.
Lautenschlager said that the study is groundbreaking.
"We believe this trial is the first to demonstrate that exercise can improve cognitive function in older adults at risk," she said.
The mental benefits seem to stick, too. She said that re-testing six and 12 months after the activity program, the memory improvements continued.
And of course, there are all the related benefits of exercise:
"Unlike medication, which was found to have no significant effect on mild cognitive impairment, physical activity has the advantage of other health benefits such as preventing depression, quality of life, falls, cardiovascular function and disability, Lautenschlager said.
"We have known for a long time that exercise is a great way to improve cardiovascular health, but it may be that in the future exercise can also be recommended to protect against the ageing brain."
Still another reason to leave the car keys at home, and hoof it to where you're going.
Not only does it save gas, save money and keep you fit.
It might help you remember where you left the car keys.
© 2008 Jan TenBruggencate
Wednesday, September 3, 2008
Sea levels are rising, and there are signs the water is coming up faster and farther than previously estimated.
The rising isn't calculated from arcane computer models or theory. It's pure gauge-reading. It's come up more than half a foot in the last century, and appears to be rising faster now than at the beginning of the last half-century.
New evidence—which does involve some modeling based on conditions observed in the field—suggests that already scary predictions may be understating how much more we can expect in the next half century.
Which raises the question: Are we in Hawai'i taking this seriously? What planning is underway for armoring crucial coastal roads or moving sewer lines inland? What serious thought is being given to Waikiki as Venice, its streets underwater? On an international airport awash at high tide?
Elsewhere in the world people are doing the planning. The Dutch, of course, are in the lead. They don't have much choice, since they're already below water level, and they lose a quarter of their country if the dikes fail.
They're not into theories. They are the best in the world at coastal management, and they take their sea level planning deadly seriously, Here's what their best estimates of sea level change suggest.
They're planning for four feet of rise in this century, and six to 12 more feet in the next. They're estimating it will cost them nearly $3 billion to deal with that. The nation organized a commission to plan for it—the Delta Commission—and has received the commission's first major report. Why?
"Our children will inherit this country, just as we did from our parents and we feel that responsibility," said Prime Minister Jan Peter Balkenende, quoted in a Reuters report.
One could reasonably ask where Hawai'i's commission is. What's Hawai'i's policy in rising water? Armor the shore? Retreat? Are we willing to build levees around our low-lying communities? Should we? Virtually every beach park disappears under these scenarios. Is anyone looking for opportunities for the coastal recreation of the next century, as the leaders of the last century did?
Recent research is providing suggestions that sea level rise could come faster than has been anticipated. Certainly, of the work is based on estimates and calculations that could be flawed. There is little consensus, for instance, on how much impact Greenland's melting glaciers will have on sea levels—only that if they melt significantly, the impact will far exceed most current estimates of rise.
But increasingly, coastal areas are paying attention to their vulnerability.
The threats to New Orleans have been adequately discussed recently.
In Vancouver, there's concern about risks to the lower areas, including the airport: http://www.canada.com/vancouversun/news/story.html?id=55a2781c-7e60-4d12-a825-a5d8d7668032.
© 2008 Jan TenBruggencate
Tuesday, September 2, 2008
When the earth moves, experience suggests that there's always some shaking.
Seems reasonable, but new evidence from Hawai'i shows it's not always true.
It seems that if the earth moves slowly enough, it can make significant and measurable changes without anybody actually being able to feel it.
Scientists working at Kīlauea were able to measure such a shudder-less earthquake in an event in 2007. They reported their findings in the journal Science last week, under the headline, “Magmatically Triggered Slow Slip at Kilauea Volcano, Hawai'i. The researchers included Benjamin Brooks, James Foster and Cecily Wolfe of the University of Hawai'i's School of Ocean and Earth Science and Technology, David Sandwell and David Myer of Scripps Institution, and Paul Okubo and Michael Poland of the USGS Hawaiian Volcano Observatory.
Their focus was an event at the volcano in mid-June 2007, in which an underground region of the volcano was subjected to what geologists call a dike intrusion, in which magma pushes into a new region. (Magma is molten rock when it's still underground. It's lava when it hits the surface.)
Using highly accurate global positioning system sensors, volcano
scientists were able to show that the dike intrusion at the rift zone
triggered an earthquake on Kilauea's flank. But they hadn't measured active seismic activity—ground shaking—associated with the movement.
The mechanics of this are something of a mystery, they say.
They call these spontaneous aseismic slip events or slow-slip events.
“The underlying process that generates seismic waves is the rupture of a fault. In typical earthquakes, this fault rupture occurs rapidly (within seconds) and this rapid rupture of a fault generates the seismic waves that people feel and that do all the damage,” said co-researcher Wolfe.
In the June 2007 event, the ground movement occurred very slowly, over hours and days. So slowly, that the ground moved, but did not shake. An earthquake without a seismic wave.
That requires some explanation to those of us who assume that the quaking and the shaking are the same thing. Wolfe said that the earthquake is different from the shake. The quake is the process that involves the originating ground movement. The shaking is the seismic wave that can result from that quake, if we understand this correctly.
“Earthquakes are not themselves seismic waves, rather earthquakes are a process that typically generates seismic waves,” she wrote in an email.
But like a Ninja moving down a path, so slowly that his passage can not be heard, it is possible for the earth to move without the shuddering—and that's a pretty new discovery to science.
"'Slow earthquakes' are a special type/new class of earthquake that has only been recently discovered (within the past decade or so), where the fault rupture occurs so slowly (over hours or days or even months) that the earthquake does not generate any strong seismic waves,” Wolfe said.
© 2008 Jan TenBruggencate