Category Archives: environment

Desalination waste as a useful resource?

For anyone not familiar with the concept, it’s possible to remove salt from water to make it potable (i.e., drinkable). With growing concerns about water shortages worldwide, turning the ocean into something drinkable is seen as a reasonable solution. One of the problems associated with the solution is waste. As you can see in this post, it’s a big problem.

Illustration depicts the potential of the suggested process. Brine, which could be obtained from the waste stream of reverse osmosis (RO) desalination plants, or from industrial plants or salt mining operations, can be processed to yield useful chemicals such as sodium hydroxide (NaOH) or hydrochloric acid (HCl). Credit: Illustration courtesy of the researchers [downloaded from https://www.sciencedaily.com/releases/2019/02/190213124439.htm]

A February 13, 2019 news item on ScienceDaily announced research from MIT (Massachusetts Institute of Technology) into research on desalination and waste,

The rapidly growing desalination industry produces water for drinking and for agriculture in the world’s arid coastal regions. But it leaves behind as a waste product a lot of highly concentrated brine, which is usually disposed of by dumping it back into the sea, a process that requires costly pumping systems and that must be managed carefully to prevent damage to marine ecosystems. Now, engineers at MIT say they have found a better way.

In a new study, they show that through a fairly simple process the waste material can be converted into useful chemicals — including ones that can make the desalination process itself more efficient

A February 13, 2019 MIT news release (also on EurekAlert), which originated the news item, describes the work in detail,

The approach can be used to produce sodium hydroxide, among other products. Otherwise known as caustic soda, sodium hydroxide can be used to pretreat seawater going into the desalination plant. This changes the acidity of the water, which helps to prevent fouling of the membranes used to filter out the salty water — a major cause of interruptions and failures in typical reverse osmosis desalination plants.

The concept is described today in the journal Nature Catalysis and in two other papers by MIT research scientist Amit Kumar, professor of mechanical engineering John. [sic] H. Lienhard V, and several others. Lienhard is the Jameel Professor of Water and Food and the director of the Abdul Latif Jameel Water and Food Systems Lab.

“The desalination industry itself uses quite a lot of it,” Kumar says of sodium hydroxide. “They’re buying it, spending money on it. So if you can make it in situ at the plant, that could be a big advantage.” The amount needed in the plants themselves is far less than the total that could be produced from the brine, so there is also potential for it to be a saleable product.

Sodium hydroxide is not the only product that can be made from the waste brine: Another important chemical used by desalination plants and many other industrial processes is hydrochloric acid, which can also easily be made on site from the waste brine using established chemical processing methods. The chemical can be used for cleaning parts of the desalination plant, but is also widely used in chemical production and as a source of hydrogen.

Currently, the world produces more than 100 billion liters (about 27 billion gallons) a day of water from desalination, which leaves a similar volume of concentrated brine. [emphases mine] Much of that is pumped back out to sea, and current regulations require costly outfall systems to ensure adequate dilution of the salts. Converting the brine can thus be both economically and ecologically beneficial, especially as desalination continues to grow rapidly around the world. “Environmentally safe discharge of brine is manageable with current technology, but it’s much better to recover resources from the brine and reduce the amount of brine released,” Lienhard says.

The method of converting the brine into useful products uses well-known and standard chemical processes, including initial nanofiltration to remove undesirable compounds, followed by one or more electrodialysis stages to produce the desired end product. While the processes being suggested are not new, the researchers have analyzed the potential for production of useful chemicals from brine and proposed a specific combination of products and chemical processes that could be turned into commercial operations to enhance the economic viability of the desalination process, while diminishing its environmental impact.

“This very concentrated brine has to be handled carefully to protect life in the ocean, and it’s a resource waste, and it costs energy to pump it back out to sea,” so turning it into a useful commodity is a win-win, Kumar says. And sodium hydroxide is such a ubiquitous chemical that “every lab at MIT has some,” he says, so finding markets for it should not be difficult.

The researchers have discussed the concept with companies that may be interested in the next step of building a prototype plant to help work out the real-world economics of the process. “One big challenge is cost — both electricity cost and equipment cost,” at this stage, Kumar says.

The team also continues to look at the possibility of extracting other, lower-concentration materials from the brine stream, he says, including various metals and other chemicals, which could make the brine processing an even more economically viable undertaking.

“One aspect that was mentioned … and strongly resonated with me was the proposal for such technologies to support more ‘localized’ or ‘decentralized’ production of these chemicals at the point-of-use,” says Jurg Keller, a professor of water management at the University of Queensland in Australia, who was not involved in this work. “This could have some major energy and cost benefits, since the up-concentration and transport of these chemicals often adds more cost and even higher energy demand than the actual production of these at the concentrations that are typically used.”

The research team also included MIT postdoc Katherine Phillips and undergraduate Janny Cai, and Uwe Schroder at the University of Braunschweig, in Germany. The work was supported by Cadagua, a subsidiary of Ferrovial, through the MIT Energy Initiative.

Here’s a link to and a citation for the paper,

Direct electrosynthesis of sodium hydroxide and hydrochloric acid from brine streams by Amit Kumar, Katherine R. Phillips, Gregory P. Thiel, Uwe Schröder, & John H. Lienhard V. Nature Catalysis volume 2, pages106–113 (2019) DOI: https://doi.org/10.1038/s41929-018-0218-y Published 13 February 2019

This paper is behind a paywall.

Let them (Rice University scientists) show you how to restore oil-soaked soil

I did not want to cash in (so to speak) on someone else’s fun headline so I played with it. Hre is the original head, which was likely written by either David Ruth or Mike Williams at Rice University (Texas, US), “Lettuce show you how to restore oil-soaked soil.”

A February 1, 2019 news item on ScienceDaily on the science behind lettuce and oil-soaked soil,

Rice University engineers have figured out how soil contaminated by heavy oil can not only be cleaned but made fertile again.

How do they know it works? They grew lettuce.

Rice engineers Kyriacos Zygourakis and Pedro Alvarez and their colleagues have fine-tuned their method to remove petroleum contaminants from soil through the age-old process of pyrolysis. The technique gently heats soil while keeping oxygen out, which avoids the damage usually done to fertile soil when burning hydrocarbons cause temperature spikes.

Lettuce growing in once oil-contaminated soil revived by a process developed by Rice University engineers. The Rice team determined that pyrolyzing oil-soaked soil for 15 minutes at 420 degrees Celsius is sufficient to eliminate contaminants while preserving the soil’s fertility. The lettuce plants shown here, in treated and fertilized soil, showed robust growth over 14 days. Photo by Wen Song

A February 1, 2019 Rice University news release (also on EurekAlert), which originated the news item, explains more about the work,

While large-volume marine spills get most of the attention, 98 percent of oil spills occur on land, Alvarez points out, with more than 25,000 spills a year reported to the Environmental Protection Agency. That makes the need for cost-effective remediation clear, he said.

“We saw an opportunity to convert a liability, contaminated soil, into a commodity, fertile soil,” Alvarez said.

The key to retaining fertility is to preserve the soil’s essential clays, Zygourakis said. “Clays retain water, and if you raise the temperature too high, you basically destroy them,” he said. “If you exceed 500 degrees Celsius (900 degrees Fahrenheit), dehydration is irreversible.

The researchers put soil samples from Hearne, Texas, contaminated in the lab with heavy crude, into a kiln to see what temperature best eliminated the most oil, and how long it took.

Their results showed heating samples in the rotating drum at 420 C (788 F) for 15 minutes eliminated 99.9 percent of total petroleum hydrocarbons (TPH) and 94.5 percent of polycyclic aromatic hydrocarbons (PAH), leaving the treated soils with roughly the same pollutant levels found in natural, uncontaminated soil.

The paper appears in the American Chemical Society journal Environmental Science and Technology. It follows several papers by the same group that detailed the mechanism by which pyrolysis removes contaminants and turns some of the unwanted hydrocarbons into char, while leaving behind soil almost as fertile as the original. “While heating soil to clean it isn’t a new process,” Zygourakis said, “we’ve proved we can do it quickly in a continuous reactor to remove TPH, and we’ve learned how to optimize the pyrolysis conditions to maximize contaminant removal while minimizing soil damage and loss of fertility.

“We also learned we can do it with less energy than other methods, and we have detoxified the soil so that we can safely put it back,” he said.

Heating the soil to about 420 C represents the sweet spot for treatment, Zygourakis said. Heating it to 470 C (878 F) did a marginally better job in removing contaminants, but used more energy and, more importantly, decreased the soil’s fertility to the degree that it could not be reused.

“Between 200 and 300 C (392-572 F), the light volatile compounds evaporate,” he said. “When you get to 350 to 400 C (662-752 F), you start breaking first the heteroatom bonds, and then carbon-carbon and carbon-hydrogen bonds triggering a sequence of radical reactions that convert heavier hydrocarbons to stable, low-reactivity char.”

The true test of the pilot program came when the researchers grew Simpson black-seeded lettuce, a variety for which petroleum is highly toxic, on the original clean soil, some contaminated soil and several pyrolyzed soils. While plants in the treated soils were a bit slower to start, they found that after 21 days, plants grown in pyrolyzed soil with fertilizer or simply water showed the same germination rates and had the same weight as those grown in clean soil.

“We knew we had a process that effectively cleans up oil-contaminated soil and restores its fertility,” Zygourakis said. “But, had we truly detoxified the soil?”

To answer this final question, the Rice team turned to Bhagavatula Moorthy, a professor of neonatology at Baylor College of Medicine, who studies the effects of airborne contaminants on neonatal development. Moorthy and his lab found that extracts taken from oil-contaminated soils were toxic to human lung cells, while exposing the same cell lines to extracts from treated soils had no adverse effects. The study eased concerns that pyrolyzed soil could release airborne dust particles laced with highly toxic pollutants like PAHs.

”One important lesson we learned is that different treatment objectives for regulatory compliance, detoxification and soil-fertility restoration need not be mutually exclusive and can be simultaneously achieved,” Alvarez said.

Here’s a link to and a citation for the paper,

Pilot-Scale Pyrolytic Remediation of Crude-Oil-Contaminated Soil in a Continuously-Fed Reactor: Treatment Intensity Trade-Offs by Wen Song, Julia E. Vidonish, Roopa Kamath, Pingfeng Yu, Chun Chu, Bhagavatula Moorthy, Baoyu Gao, Kyriacos Zygourakis, and Pedro J. J. Alvarez. Environ. Sci. Technol., 2019, 53 (4), pp 2045–2053 DOI: 10.1021/acs.est.8b05825 Publication Date (Web): January 25, 2019

Copyright © 2019 American Chemical Society

This paper is behind a paywall.

Eco-friendly nanocomposite catalyst and ultrasound to remove pollutants from water

The best part of this story is that they’re using biochar from rice hulls to create the nanocomposite catalyst. A July 19, 2019 news item on ScienceDaily reveals a few details about the research without discussing the rice hulls,

The research team of Dr. Jae-woo Choi and Dr. Kyung-won Jung of the Korea Institute of Science and Technology’s (KIST, president: Byung-gwon Lee) Water Cycle Research Center announced that it has developed a wastewater treatment process that uses a common agricultural byproduct to effectively remove pollutants and environmental hormones, which are known to be endocrine disruptors.

A July 19, 2019 Korea National Research Council of Science & Technology news release on EurekAlert, which originated the news item, provides more detail,

The sewage and wastewater that are inevitably produced at any industrial worksite often contain large quantities of pollutants and environmental hormones (endocrine disruptors). Because environmental hormones do not break down easily, they can have a significant negative effect on not only the environment but also the human body. To prevent this, a means of removing environmental hormones is required.

The performance of the catalyst that is currently being used to process sewage and wastewater drops significantly with time. Because high efficiency is difficult to achieve given the conditions, the biggest disadvantage of the existing process is the high cost involved. Furthermore, the research done thus far has mostly focused on the development of single-substance catalysts and the enhancement of their performance. Little research has been done on the development of eco-friendly nanocomposite catalysts that are capable of removing environmental hormones from sewage and wastewater.

The KIST research team, led by Dr. Jae-woo Choi and Dr. Kyung-won Jung, utilized biochar,** which is eco-friendly and made from agricultural byproducts, to develop a wastewater treatment process that effectively removes pollutants and environmental hormones. The team used rice hulls [emphasis mine] which are discarded during rice harvesting, to create a biochar that is both eco-friendly and economical. The surface of the biochar was coated with nano-sized manganese dioxide to create a nanocomposite. The high efficiency and low cost of the biochar-nanocomposite catalyst is based on the combination of the advantages of the biochar and manganese dioxide.

**Biochar: a term that collectively refers to substances that can be created through the thermal decomposition of diverse types of biomass or wood under oxygen-limited condition

The KIST team used the hydrothermal method, which is a type of mineral synthesis that uses high heat and pressure, when synthesizing the nanocomposite in order to create a catalyst that is highly active, easily replicable, and stable. It was confirmed that giving the catalyst a three-dimensional stratified structure resulted in the high effectiveness of the advanced oxidation process (AOP), due to the large surface area created.

When used under the same conditions in which the existing catalyst can remove only 80 percent of Bisphenol A (BPA), an environmental hormone, the catalyst developed by the KIST team removed over 95 percent in less than one hour. In particular, when combined with ultrasound (20kHz), it was confirmed that all traces of BPA were completely removed in less than 20 minutes. Even after many repeated tests, the BPA removal rate remained consistently at around 93 percent.

Dr. Kyung-won Jung of KIST’s Water Cycle Research Center said, “The catalyst developed through this study makes use of a common agricultural byproduct. Therefore, we expect that additional research on alternative substances will lead to the development of catalysts derived from various types of organic waste biomass.” Dr. Jae-woo Choi, also of KIST’s Water Cycle Research Center, said, “We have high hopes that future studies aimed at achieving process optimization and increasing removal rates will allow for the development an environmental hormone removal system that is both eco-friendly and low-cost.”

Here’s a link to and a citation for the paper,

Ultrasound-assisted heterogeneous Fenton-like process for bisphenol A removal at neutral pH using hierarchically structured manganese dioxide/biochar nanocomposites as catalysts by Kyung-Won Jung, Seon Yong Lee, Young Jae Lee, Jae-Woo Choi. Ultrasonics Sonochemistry
Volume 57, October 2019, Pages 22-28 DOI: https://doi.org/10.1016/j.ultsonch.2019.04.039 Available online 29 April 2019

This paper is behind a paywall.

Better performing solar cells with newly discovered property of pristine graphene

Light-harvesting devices—I like that better than solar cells or the like but I think that the term serves as a category rather than a name/label for a specific device. Enough musing. A December 17, 2018 news item on Nanowerk describes the latest about graphene and light-harvesting devices (Note: A link has been removed,

An international research team, co-led by a physicist at the University of California, Riverside, has discovered a new mechanism for ultra-efficient charge and energy flow in graphene, opening up opportunities for developing new types of light-harvesting devices.

The researchers fabricated pristine graphene — graphene with no impurities — into different geometric shapes, connecting narrow ribbons and crosses to wide open rectangular regions. They found that when light illuminated constricted areas, such as the region where a narrow ribbon connected two wide regions, they detected a large light-induced current, or photocurrent.

The finding that pristine graphene can very efficiently convert light into electricity could lead to the development of efficient and ultrafast photodetectors — and potentially more efficient solar panels.

A December 14, 2018 University of California at Riverside (UCR) news release by Iqbal Pittalwala (also on EurekAlert but published Dec. 17, 2018), which originated the news item,gives a brief description of graphene while adding context for this research,


Graphene, a 1-atom thick sheet of carbon atoms arranged in a hexagonal lattice, has many desirable material properties, such as high current-carrying capacity and thermal conductivity. In principle, graphene can absorb light at any frequency, making it ideal material for infrared and other types of photodetection, with wide applications in bio-sensing, imaging, and night vision.

In most solar energy harvesting devices, a photocurrent arises only in the presence of a junction between two dissimilar materials, such as “p-n” junctions, the boundary between two types of semiconductor materials. The electrical current is generated in the junction region and moves through the distinct regions of the two materials.

“But in graphene, everything changes,” said Nathaniel Gabor, an associate professor of physics at UCR, who co-led the research project. “We found that photocurrents may arise in pristine graphene under a special condition in which the entire sheet of graphene is completely free of excess electronic charge. Generating the photocurrent requires no special junctions and can instead be controlled, surprisingly, by simply cutting and shaping the graphene sheet into unusual configurations, from ladder-like linear arrays of contacts, to narrowly constricted rectangles, to tapered and terraced edges.”

Pristine graphene is completely charge neutral, meaning there is no excess electronic charge in the material. When wired into a device, however, an electronic charge can be introduced by applying a voltage to a nearby metal. This voltage can induce positive charge, negative charge, or perfectly balance negative and positive charges so the graphene sheet is perfectly charge neutral.

“The light-harvesting device we fabricated is only as thick as a single atom,” Gabor said. “We could use it to engineer devices that are semi-transparent. These could be embedded in unusual environments, such as windows, or they could be combined with other more conventional light-harvesting devices to harvest excess energy that is usually not absorbed. Depending on how the edges are cut to shape, the device can give extraordinarily different signals.”

The research team reports this first observation of an entirely new physical mechanism — a photocurrent generated in charge-neutral graphene with no need for p-n junctions — in Nature Nanotechnology today [Dec. 17, 2018].

Previous work by the Gabor lab showed a photocurrent in graphene results from highly excited “hot” charge carriers. When light hits graphene, high-energy electrons relax to form a population of many relatively cooler electrons, Gabor explained, which are subsequently collected as current. Even though graphene is not a semiconductor, this light-induced hot electron population can be used to generate very large currents.

“All of this behavior is due to graphene’s unique electronic structure,” he said. “In this ‘wonder material,’ light energy is efficiently converted into electronic energy, which can subsequently be transported within the material over remarkably long distances.”

He explained that, about a decade ago, pristine graphene was predicted to exhibit very unusual electronic behavior: electrons should behave like a liquid, allowing energy to be transferred through the electronic medium rather than by moving charges around physically.
“But despite this prediction, no photocurrent measurements had been done on pristine graphene devices — until now,” he said.

The new work on pristine graphene shows electronic energy travels great distances in the absence of excess electronic charge.

The research team has found evidence that the new mechanism results in a greatly enhanced photoresponse in the infrared regime with an ultrafast operation speed.
“We plan to further study this effect in a broad range of infrared and other frequencies, and measure its response speed,” said first author Qiong Ma, a postdoctoral associate in physics at the Massachusetts Institute of Technology, or MIT.

The researchers have provided an image illustrating their work,

Caption: Shining light on graphene: Although graphene has been studied vigorously for more than a decade, new measurements on high-performance graphene devices have revealed yet another unusual property. In ultra-clean graphene sheets, energy can flow over great distances, giving rise to an unprecedented response to light. Credit: Max Grossnickle and QMO Labs, UC Riverside.

Here’s a link to and a citation for the paper,

Giant intrinsic photoresponse in pristine graphene by Qiong Ma, Chun Hung Lui, Justin C. W. Song, Yuxuan Lin, Jian Feng Kong, Yuan Cao, Thao H. Dinh, Nityan L. Nair, Wenjing Fang, Kenji Watanabe, Takashi Taniguchi, Su-Yang Xu, Jing Kong, Tomás Palacios, Nuh Gedik, Nathaniel M. Gabor, & Pablo Jarillo-Herrero. Nature Nanotechnology (2018) Published 17 December 2018 DOI: https://doi.org/10.1038/s41565-018-0323-8

This paper is behind a paywall.

Jiggly jell-o as a new hydrogen fuel catalyst

Jello [uploaded from https://www.organicauthority.com/eco-chic-table/new-jell-o-mold-jiggle-chic-holidays]

I’m quite intrigued by this ‘jell-o’ story. It’s hard to believe a childhood dessert might prove to have an application as a catalyst for producing hydrogen fuel. From a December 14, 2018 news item on Nanowerk,

A cheap and effective new catalyst developed by researchers at the University of California, Berkeley, can generate hydrogen fuel from water just as efficiently as platinum, currently the best — but also most expensive — water-splitting catalyst out there.

The catalyst, which is composed of nanometer-thin sheets of metal carbide, is manufactured using a self-assembly process that relies on a surprising ingredient: gelatin, the material that gives Jell-O its jiggle.

Two-dimensional metal carbides spark a reaction that splits water into oxygen and valuable hydrogen gas. Berkeley researchers have discovered an easy new recipe for cooking up these nanometer-thin sheets that is nearly as simple as making Jell-O from a box. (Xining Zang graphic, copyright Wiley)

A December 13, 2018 University of California at Berkeley (UC Berkeley) news release by Kara Manke (also on EurekAlert but published on Dec. 14, 2018), which originated the news item, provides more technical detail,

“Platinum is expensive, so it would be desirable to find other alternative materials to replace it,” said senior author Liwei Lin, professor of mechanical engineering at UC Berkeley. “We are actually using something similar to the Jell-O that you can eat as the foundation, and mixing it with some of the abundant earth elements to create an inexpensive new material for important catalytic reactions.”

The work appears in the Dec. 13 [2018] print edition of the journal Advanced Materials.

A zap of electricity can break apart the strong bonds that tie water molecules together, creating oxygen and hydrogen gas, the latter of which is an extremely valuable source of energy for powering hydrogen fuel cells. Hydrogen gas can also be used to help store energy from renewable yet intermittent energy sources like solar and wind power, which produce excess electricity when the sun shines or when the wind blows, but which go dormant on rainy or calm days.

A black and white image of metal carbide under high magnification.

When magnified, the two-dimensional metal carbides resemble sheets of cell[o]phane. (Xining Zang photo, copyright Wiley)

But simply sticking an electrode in a glass of water is an extremely inefficient method of generating hydrogen gas. For the past 20 years, scientists have been searching for catalysts that can speed up this reaction, making it practical for large-scale use.

“The traditional way of using water gas to generate hydrogen still dominates in industry. However, this method produces carbon dioxide as byproduct,” said first author Xining Zang, who conducted the research as a graduate student in mechanical engineering at UC Berkeley. “Electrocatalytic hydrogen generation is growing in the past decade, following the global demand to lower emissions. Developing a highly efficient and low-cost catalyst for electrohydrolysis will bring profound technical, economical and societal benefit.”

To create the catalyst, the researchers followed a recipe nearly as simple as making Jell-O from a box. They mixed gelatin and a metal ion — either molybdenum, tungsten or cobalt — with water, and then let the mixture dry.

“We believe that as gelatin dries, it self-assembles layer by layer,” Lin said. “The metal ion is carried by the gelatin, so when the gelatin self-assembles, your metal ion is also arranged into these flat layers, and these flat sheets are what give Jell-O its characteristic mirror-like surface.”

Heating the mixture to 600 degrees Celsius triggers the metal ion to react with the carbon atoms in the gelatin, forming large, nanometer-thin sheets of metal carbide. The unreacted gelatin burns away.

The researchers tested the efficiency of the catalysts by placing them in water and running an electric current through them. When stacked up against each other, molybdenum carbide split water the most efficiently, followed by tungsten carbide and then cobalt carbide, which didn’t form thin layers as well as the other two. Mixing molybdenum ions with a small amount of cobalt boosted the performance even more.

“It is possible that other forms of carbide may provide even better performance,” Lin said.

On the left, an illustration of blue spheres, representing gelatin molecules, arranged in a lattice shape. On the right, an illustration of thin sheets of metal carbide.

Molecules in gelatin naturally self-assemble in flat sheets, carrying the metal ions with them (left). Heating the mixture to 600 degrees Celsius burns off the gelatin, leaving nanometer-thin sheets of metal carbide. (Xining Zang illustration, copyright Wiley)

The two-dimensional shape of the catalyst is one of the reasons why it is so successful. That is because the water has to be in contact with the surface of the catalyst in order to do its job, and the large surface area of the sheets mean that the metal carbides are extremely efficient for their weight.

Because the recipe is so simple, it could easily be scaled up to produce large quantities of the catalyst, the researchers say.

“We found that the performance is very close to the best catalyst made of platinum and carbon, which is the gold standard in this area,” Lin said. “This means that we can replace the very expensive platinum with our material, which is made in a very scalable manufacturing process.”

Co-authors on the study are Lujie Yang, Buxuan Li and Minsong Wei of UC Berkeley, J. Nathan Hohman and Chenhui Zhu of Lawrence Berkeley National Lab; Wenshu Chen and Jiajun Gu of Shanghai Jiao Tong University; Xiaolong Zou and Jiaming Liang of the Shenzhen Institute; and Mohan Sanghasadasa of the U.S. Army RDECOM AMRDEC.

Here’s a link to and a citation for the paper,

Self‐Assembly of Large‐Area 2D Polycrystalline Transition Metal Carbides for Hydrogen Electrocatalysis by Xining Zang, Wenshu Chen, Xiaolong Zou, J. Nathan Hohman, Lujie Yang
Buxuan Li, Minsong Wei, Chenhui Zhu, Jiaming Liang, Mohan Sanghadasa, Jiajun Gu, Liwei Lin. Advanced Materials Volume30, Issue 50 December 13, 2018 1805188 DOI: https://doi.org/10.1002/adma.201805188 First published [online]: 09 October 2018

This paper is behind a paywall.

In six hours billions of plastic nanoparticles accumulate in marine organisms

For the sake of comparison, I wish they’d thought to include an image of a giant scallop that hadn’t been used in the research (I have an ‘unplastic’ giant scallop image at the end of this posting),

Caption: These are some of the scallops used as part of the current research. Credit: University of Plymouth

But, they did do this,

A scan showing nanoplastic particles accumulated within the scallop’s gills (GI), kidney (K), gonad (GO), intestine (I), hepatopancreas (HP) and muscle (M). Credit: University of Plymouth [downloaded from https://phys.org/news/2018-12-billions-nanoplastics-accumulate-marine-hours.html]

A December 3, 2018 news item on phys.org announces the research,

A ground-breaking study has shown it takes a matter of hours for billions of minute plastic nanoparticles to become embedded throughout the major organs of a marine organism.

The research, led by the University of Plymouth, examined the uptake of nanoparticles by a commercially important mollusc, the great scallop (Pecten maximus).

After six hours exposure in the laboratory, billions of particles measuring 250nm (around 0.00025mm) had accumulated within the scallop’s intestines.

However, considerably more even smaller particles measuring 20nm (0.00002mm) had become dispersed throughout the body including the kidney, gill, muscle and other organs.

A December 3, 2018 University of Plymouth press release (also on EurekAlert), which originated the news item, adds more detail,

The study is the first to quantify the uptake of nanoparticles at predicted environmentally relevant conditions, with previous research having been conducted at far higher concentrations than scientists believe are found in our oceans.

Dr Maya Al Sid Cheikh, Postdoctoral Research Fellow at the University of Plymouth, led the study. She said: “For this experiment, we needed to develop an entirely novel scientific approach. We made nanoparticles of plastic in our laboratories and incorporated a label so that we could trace the particles in the body of the scallop at environmentally relevant concentrations. The results of the study show for the first time that nanoparticles can be rapidly taken up by a marine organism, and that in just a few hours they become distributed across most of the major organs.”

Professor Richard Thompson OBE, Head of the University’s International Marine Litter Research Unit, added: “This is a ground breaking study, in terms of both the scientific approach and the findings. We only exposed the scallops to nanoparticles for a few hours and, despite them being transferred to clean conditions, traces were still present several weeks later. Understanding the dynamics of nanoparticle uptake and release, as well as their distribution in body tissues, is essential if we are to understand any potential effects on organisms. A key next step will be to use this approach to guide research investigating any potential effects of nanoparticles and in particular to consider the consequences of longer term exposures.”

Accepted for publication in the Environmental Science and Technology journal, the study also involved scientists from the Charles River Laboratories in Elphinstone, Scotland; the Institute Maurice la Montagne in Canada; and Heriot-Watt University.

It was conducted as part of RealRiskNano, a £1.1million project funded by the Natural Environment Research Council (NERC). Led by Heriot-Watt and Plymouth, it is exploring the effects which microscopic plastic particles can have on the marine environment.

In this study, the scallops were exposed to quantities of carbon-radiolabeled nanopolystyrene and after six hours, autoradiography was used to show the number of particles present in organs and tissue.

It was also used to demonstrate that the 20nm particles were no longer detectable after 14 days, whereas 250nm particles took 48 days to disappear.

Ted Henry, Professor of Environmental Toxicology at Heriot-Watt University, said: “Understanding whether plastic particles are absorbed across biological membranes and accumulate within internal organs is critical for assessing the risk these particles pose to both organism and human health. The novel use of radiolabelled plastic particles pioneered in Plymouth provides the most compelling evidence to date on the level of absorption of plastic particles in a marine organism.”

Here’s a link to and a citation for the paper,

Uptake, Whole-Body Distribution, and Depuration of Nanoplastics by the Scallop Pecten maximus at Environmentally Realistic Concentrations by Maya Al-Sid-Cheikh, Steve J. Rowland, Karen Stevenson, Claude Rouleau, Theodore B. Henry, and Richard C. Thompson. Environ. Sci. Technol., Article ASAP DOI: 10.1021/acs.est.8b05266 Publication Date (Web): November 20, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

‘Unplastic giant scallop’

The sea scallop (Placopecten magellanicus) has over 100 blue eyes along the edge of its mantle, with which it senses light intensity. This mollusk has the ability to scoot away from potential danger by flapping the two parts of its shell, like a swimming castenet. Credit: Dann Blackwood, USGS – http://www.sanctuaries.nos.noaa.gov/pgallery/pgstellwagen/living/living_17.html Public Domain

Stunning, isn’t it?

Chen Qiufan, garbage, and Chinese science fiction stories

Garbage has been dominating Canadian news headlines for a few weeks now. First, it was Canadian garbage in the Philippines and now it’s Canadian garbage in Malaysia. Interestingly, we’re also having problems with China, since December 2018, when we detained a top executive from Huawe, a China-based international telecommunicatons company, in accordance with an official request from the US government and, in accordance, with what Prime Minister Justin Trudeau calls the ‘rule of law’. All of this provides an interesting backdrop (for Canadians anyway) on the topic of China, garbage, and science fiction.

A May 16, 2019 article by Anjie Zheng for Fast Company explores some of the latest and greatest from China’s science fiction writing community,

Like any good millennial, I think about my smartphone, to the extent that I do at all, in terms of what it does for me. It lets me message friends, buy stuff quickly, and amass likes. I hardly ever think about what it actually is—a mass of copper wires, aluminum alloys, and lithium battery encased in glass—or where it goes when I upgrade.

Chen Qiufan wants us to think about that. His debut novel, Waste Tide, is set in a lightly fictionalized version of Guiyu, the world’s largest electronic waste disposal. First published in Chinese in 2013, the book was recently released in the U.S. with a very readable translation into English by Ken Liu.

Chen, who has been called “China’s William Gibson,” is part of a younger generation of sci-fi writers who have achieved international acclaim in recent years. Liu Cixin became the first Chinese to win the prestigious Hugo Award for his Three Body Problem in 2015. The Wandering Earth, based on a short story by Liu, became China’s first science-fiction blockbuster when it was released in 2018. It was the highest-grossing film in the fastest-growing film market in the world last year and was recently scooped up by Netflix.

Aynne Kokas in a March 13, 2019 article for the Washington Post describes how the hit film, The Wandering Earth, fits into an overall Chinese-led movie industry focused on the future and Hollywood-like, i. e. like US movie industry, domination,

“The Wandering Earth,” directed by Frant Gwo, takes place in a future where the people of Earth must flee their sun as it swells into a red giant. Thousands of engines — the first of them constructed in Hangzhou, one of China’s tech hubs — propel the entire planet toward a new solar system, while everyone takes refuge from the cold in massive underground cities. On the surface, the only visible reminders of the past are markers of China’s might. The Shanghai Tower, the Oriental Pearl Tower and a stadium for the Shanghai 2044 Olympics all thrust out of the ice, having apparently survived the journey’s tsunamis, deep freeze and cliff-collapsing earthquakes.

The movie is China’s first big-budget sci-fi epic, and its production was ambitious, involving some 7,000 workers and 10,000 specially-built props. Audience excitement was correspondingly huge: Nearly half a million people wrote reviews of the film on Chinese social network site Douban. Having earned over $600 million in domestic sales, “The Wandering Earth” marks a major achievement for the country’s film industry.

It is also a major achievement for the Chinese government.

Since opening up the country’s film market in 2001, the Chinese government has aspired to learn from Hollywood how to make commercially appealing films, as I detail in my book “Hollywood Made in China.” From initial private offerings for state media companies, to foreign investment in films, studios and theme parks, the government allowed outside capital and expertise to grow the domestic commercial film industry — but not at the expense of government oversight. This policy’s underlying aim was to expand China’s cultural clout and political influence.

Until recently, Hollywood films dominated the country’s growing box office. That finally changed in 2015, with the release of major local blockbusters “Monster Hunt” and “Lost in Hong Kong.” The proliferation of homegrown hits signaled that the Chinese box office profits no longer depend on Hollywood studio films — sending an important message to foreign trade negotiators and studios.

Kokas provides some insight into how the Chinese movie industry is designed to further the Chinese government’s vision of the future. As a Canadian, I don’t see that much difference between the US and China industry’s vision. Both tout themselves as the answer to everything, both target various geographic regions for the ‘bad guys’, and both tout their national moral superiority in their films. I suppose the same can be said for most countries’ film industries but both China and the US can back themselves with economic might.

Zheng’s article delves deeper into garbage, and Chen Qiufan’s science fiction while illuminating the process of changing a ‘good guy’ into a ‘bad guy’,

Chen, 37, grew up a few miles from the real Guiyu. Mountains of scrap electronics are shipped there every year from around the world. Thousands of human workers sort through the junk for whatever can be reduced to reusable precious metals. They strip wires and disassemble circuit boards, soaking them in acid baths for bits of copper, tin, platinum, and gold. Whatever can’t be processed is burned. The water in Guiyu has been so contaminated it is undrinkable; the air is toxic. The workers, migrants from poor rural areas in China, have an abnormally high rate of respiratory diseases and cancer.

For the decades China was revving its economic engine, authorities were content to turn a blind eye to the human costs of the recycling business. It was an economic win-win. For developed countries like the U.S., it’s cheaper to ship waste to places like China than trying to recycle it themselves. And these shipments create jobs and profits for the Chinese.

In recent years, however, steps have been taken to protect workers and the environment in China. …

Waste Tide highlights the danger of “throw-away culture,” says Chen, also known in English as Stanley Chan. When our personal electronics stop serving us, whether because they break or our lust for the newest specs get the better of us, we toss them. Hopefully we’re conscientious enough to bring them to local recyclers that claim they’ll dispose of them properly. But that’s likely the end of our engagement with the trash. Out of sight, out of mind.

Fiction, and science fiction in particular, is an apt medium for Chen to probe the consequences of this arrangement. “It’s not journalism,” he says. Instead, the story is an imaginative, action-packed tale of power imbalances, and the individual characters that think they’re doing good. Waste Tide culminates, expectedly, in an insurgency of the workers against their exploitative overlords.

Guiyu has been fictionalized in Waste Tide as “Silicon Isle.” (A homophone of the Chinese character “gui” translates to “Silicon,” and “yu” is an island). The waste hell is ruled by three ruthless family clans, dominated by the Luo clan. They treat workers as slaves and derisively call them “waste people.”

Technology in the near-future has literally become extensions of selves and only exacerbates class inequality. Prosthetic inner ears improve balance; prosthetic limbs respond to mental directives; helmets heighten natural senses. The rich “switch body parts as easily as people used to switch phones.” Those with fewer means hack discarded prosthetics to get the same kick. When they’re no longer needed, synthetic body parts contaminated with blood and bodily fluids are added to the detritus.

At the center of the story is Mimi, a migrant worker who dreams of earning enough money to return home and live a quiet life. She strikes up a relationship with Kaizong, a Chinese-American college graduate trying to rediscover his roots. But the good times are short-lived. The boss of the Luo clan becomes convinced that Mimi holds the key to rousing his son from his coma and soon kidnaps the hapless girl.

For all the advanced science, there is a backwards superstition that animates Silicon Isle. [emphasis mine] The clan bosses subscribe to “a simple form of animism.” They pray to the wind and sea for ample supplies of waste. They sacrifice animals (and some humans) to bring them luck, and use local witches to exorcise evil spirits. Boss Luo has Mimi kidnapped and tortured in an effort to appease the gods in the hopes of waking up his comatose son. The torture of Mimi infects her with a mysterious disease that splits her consciousness. The waste people are enraged by her violation, which eventually sparks a war against the ruling clans. [emphasis mine]

A parallel narrative involves an American, Scott Brandle, who works for an environmental company. While in town trying to set up a recycling facility, he stumbles onto the truth about the virus that may have infected Mimi: a chemical weapon developed and used by the U.S. [emphasis mine] years earlier. Invented by a Japanese researcher [emphasis mine] working in the U.S., the drug is capable of causing mass hallucinations and terror. When Brandle learns that Mimi may have been infected with this virus, he wants a piece of her [emphasis mine] too, so that scientists back home can study its effects.

Despite portraying the future of China in a less-than-positive light, [emphasis mine] Waste Tide has not been banned–a common result for works that displease Beijing; instead, the book won China’s prestigious Nebula award for science fiction, and is about to be reprinted on the mainland. …

An interview with Chen (it’s worthwhile to read his take on what he’s doing) follows the plot description in this intriguing and what seems to be a sometimes disingenuous article.

The animism and the war against the ruling class? It reminds me a little of the tales told about old Chine and Mao’s campaign to overthrow the ruling classes who had kept control of the proletariat, in part, by encouraging ‘superstitious religious belief’.

As far as I’m concerned the interpretation can go either or both ways: a critique of the current government’s policies and where they might lead in the future and/or a reference back to the glorious rising of China’s communist government. Good fiction always contains ambiguity; it’s what fuels courses in literature.

Also, the bad guys are from the US and Japan, countries which have long been allied with each other and with which China has some serious conflicts.

Interesting, non? And, it’s not that different from what you’ll see in US (or any other country’s for that matter) science fiction wiring and movies, except that the heroes are Chinese.

Getting back to the garbage in the Philippines, there are 69 containers on their way back to Canada as of May 30, 2019. As for why all this furor about Canadian garbage in the Philippines and Malaysia, it’s hard to believe that Canada is the only sinner. Of course, we are in China’s bad books due to the Huawei executive’s detention here (she is living in her home in Vancouver and goes out and about as she wishes, albeit under surveillance).

Anyway, I can’t help but wonder if indirect pressure is being exerted by China or if the Philippines and Malaysia have been incentivized in some way by China. The timing has certainly been interesting.

Political speculation aside, it’s probably a good thing that countries are refusing to take our garbage. As I’m sure more than one environmentalist would be happy to point out, it’s about time we took care of our own mess.

Bendable phones that are partially organic

It’s been about nine  or 10 years since I first heard about bendable phones (my September 29, 2010 posting). The concept keeps popping up from time to time (my April 25, 2017 posting) and this time, we have Australian scientists to thank for this latest work described in an October 5, 2018 news item on Nanowerk (Note: A link has been removed),

Engineers at ANU [Australian National University] have invented a semiconductor with organic and inorganic materials that can convert electricity into light very efficiently, and it is thin and flexible enough to help make devices such as mobile phones bendable (Advanced Materials, “Efficient and Layer-Dependent Exciton Pumping across Atomically Thin Organic–Inorganic Type-I Heterostructures”).

The invention also opens the door to a new generation of high-performance electronic devices made with organic materials that will be biodegradable or that can be easily recycled, promising to help substantially reduce e-waste.

An October 5, 2018 ANU press release (also on EurekAlert but published October 4, 2018) expands on the theme,

The huge volumes of e-waste generated by discarded electronic devices around the world is causing irreversible damage to the environment. Australia produces 200,000 tonnes of e-waste every year – only four per cent of this waste is recycled.

The organic component has the thickness of just one atom – made from just carbon and hydrogen – and forms part of the semiconductor that the ANU team developed. The inorganic component has the thickness of around two atoms. The hybrid structure can convert electricity into light efficiently for displays on mobile phones, televisions and other electronic devices.

Lead senior researcher Associate Professor Larry Lu said the invention was a major breakthrough in the field.

“For the first time, we have developed an ultra-thin electronics component with excellent semiconducting properties that is an organic-inorganic hybrid structure and thin and flexible enough for future technologies, such as bendable mobile phones and display screens,” said Associate Professor Lu from the ANU Research School of Engineering.

PhD researcher Ankur Sharma, who recently won the ANU 3-Minute Thesis competition, said experiments demonstrated the performance of their semiconductor would be much more efficient than conventional semiconductors made with inorganic materials such as silicon.

“We have the potential with this semiconductor to make mobile phones as powerful as today’s supercomputers,” said Mr Sharma from the ANU Research School of Engineering.

“The light emission from our semiconducting structure is very sharp, so it can be used for high-resolution displays and, since the materials are ultra-thin, they have the flexibility to be made into bendable screens and mobile phones in the near future.”

The team grew the organic semiconductor component molecule by molecule, in a similar way to 3D printing. The process is called chemical vapour deposition.

“We characterised the opto-electronic and electrical properties of our invention to confirm the tremendous potential of it to be used as a future semiconductor component,” Associate Professor Lu said.

“We are working on growing our semiconductor component on a large scale, so it can be commercialised in collaboration with prospective industry partners.”

Here’s a link to and a citation for the paper,

Efficient and Layer‐Dependent Exciton Pumping across Atomically Thin Organic–Inorganic Type‐I Heterostructures by Linglong Zhang, Ankur Sharma, Yi Zhu, Yuhan Zhang, Bowen Wang, Miheng Dong, Hieu T. Nguyen, Zhu Wang, Bo Wen, Yujie Cao, Boqing Liu, Xueqian Sun, Jiong Yang, Ziyuan Li. Advanced Materials Volume30, Issue 40 1803986 (October 4, 2018) DOI:https://doi.org/10.1002/adma.201803986 First published [onliine]: 30 August 2018

This paper is behind a paywall.

How do nanoparticles interact with the environment and with humans over time?

I meant to get this piece published sooner but good intentions don’t get you far.

At Northwestern University, scientists have researched the impact engineered nanoparticles (ENPs) might have as they enter the food chain. An October 18, 2019 Northwestern University news release (also on EurekAlert) by Megan Fellman describes research on an investigation of ENPs and their interaction with living organisms,

Personal electronic devices — smartphones, computers, TVs, tablets, screens of all kinds — are a significant and growing source of the world’s electronic waste. Many of these products use nanomaterials, but little is known about how these modern materials and their tiny particles interact with the environment and living things.

Now a research team of Northwestern University chemists and colleagues from the national Center for Sustainable Nanotechnology has discovered that when certain coated nanoparticles interact with living organisms it results in new properties that cause the nanoparticles to become sticky. Fragmented lipid coronas form on the particles, causing them to stick together and grow into long kelp-like strands. Nanoparticles with 5-nanometer diameters form long structures that are microns in size in solution. The impact on cells is not known.

“Why not make a particle that is benign from the beginning?” said Franz M. Geiger, professor of chemistry in Northwestern’s Weinberg College of Arts and Sciences. He led the Northwestern portion of the research.

“This study provides insight into the molecular mechanisms by which nanoparticles interact with biological systems,” Geiger said. “This may help us understand and predict why some nanomaterial/ligand coating combinations are detrimental to cellular organisms while others are not. We can use this to engineer nanoparticles that are benign by design.”

Using experiments and computer simulations, the research team studied how gold nanoparticles wrapped in strings having positively charged beads interact with a variety of bilayer membrane models. The researchers found that a nearly circular layer of lipids forms spontaneously around the particles. Formation of these “fragmented lipid coronas” have never been seen before to form from membranes.

The study points to solving problems with chemistry. Scientists can use the findings to design a better ligand coating for nanoparticles that avoids the ammonium-phosphate interaction, which causes the aggregation. (Ligands are used in nanomaterials for layering.)

The results will be published Oct. 18 [2018] in the journal Chem.

Geiger is the study’s corresponding author. Other authors include scientists from the Center for Sustainable Nanotechnology’s other institutional partners. Based at the University of Wisconsin-Madison, the center studies engineered nanomaterials and their interaction with the environment, including biological systems — both the negative and positive aspects.

“The nanoparticles pick up parts of the lipid cellular membrane like a snowball rolling in a snowfield, and they become sticky,” Geiger said. “This unintended effect happens because of the presence of the nanoparticle. It can bring lipids to places in cells where lipids are not meant to be.”

The experiments were conducted in idealized laboratory settings that nevertheless are relevant to environments found during the late summer in a landfill — at 21-22 degrees Celsius and a couple feet below ground, where soil and groundwater mix and the food chain begins.

By pairing spectroscopic and imaging experiments with atomistic and coarse-grain simulations, the researchers identified that ion pairing between the lipid head groups of biological membranes and the polycations’ ammonium groups in the nanoparticle wrapping leads to the formation of fragmented lipid coronas. These coronas engender new properties, including composition and stickiness, to the particles with diameters below 10 nanometers.

The study’s insights help predict the impact that the increasingly widespread use of engineered nanomaterials has on the nanoparticles’ fate once they enter the food chain, which many of them may eventually do.

“New technologies and mass consumer products are emerging that feature nanomaterials as critical operational components,” Geiger said. “We can upend the existing paradigm in nanomaterial production towards one in which companies design nanomaterials to be sustainable from the beginning, as opposed to risking expensive product recalls — or worse — down the road.” [emphases mine]

Here’s an image illustrating the work,

Caption: This is a computer simulation of a lipid corona around a 5-nanometer nanoparticle showing ammonium-phosphate ion pairing. Credit: Northwestern University

The curious can find the paper here,

Lipid Corona Formation from Nanoparticle Interactions with Bilayers by Laura L. Olenick, Julianne M. Troiano, Ariane Vartanian, Eric S. Melby, Arielle C. Mensch, Leili Zhang, Jiewei Hong, Oluwaseun Mesele, Tian Qiu, Jared Bozich, Samuel Lohse, Xi Zhang, Thomas R. Kuech, Augusto Millevolte, Ian Gunsolus, Alicia C. McGeachy, Merve Doğangün, Tianzhe Li, Dehong Hu, Stephanie R. Walter, Aurash Mohaimani, Angela Schmoldt, Marco D. Torelli, Katherine R. Hurley, Joe Dalluge, Gene Chong, Z. Vivian Feng, Christy L. Haynes, Robert J. Hamers, Joel A. Pedersen, Qiang Cui, Rigoberto Hernandez, Rebecca Klaper, Galya Orr, Catherine J. Murphy, Franz M. Geiger. Chem Volume 4, ISSUE 11, P2709-2723, November 08, 2018 DOI:https://doi.org/10.1016/j.chempr.2018.09.018 Published:October 18, 2018

This paper is behind a paywall.

Iridescent giant clams could point the way to safety, climatologically speaking

Giant clams in Palau (Cynthia Barnett)

These don’t look like any clams I’ve ever seen but that is the point of Cynthia Barnett’s absorbing Sept. 10, 2018 article for The Atlantic (Note: A link has been removed),

Snorkeling amid the tree-tangled rock islands of Ngermid Bay in the western Pacific nation of Palau, Alison Sweeney lingers at a plunging coral ledge, photographing every giant clam she sees along a 50-meter transect. In Palau, as in few other places in the world, this means she is going to be underwater for a skin-wrinkling long time.

At least the clams are making it easy for Sweeney, a biophysicist at the University of Pennsylvania. The animals plump from their shells like painted lips, shimmering in blues, purples, greens, golds, and even electric browns. The largest are a foot across and radiate from the sea floor, but most are the smallest of the giant clams, five-inch Tridacna crocea, living higher up on the reef. Their fleshy Technicolor smiles beam in all directions from the corals and rocks of Ngermid Bay.

… Some of the corals are bleached from the conditions in Ngermid Bay, where naturally high temperatures and acidity mirror the expected effects of climate change on the global oceans. (Ngermid Bay is more commonly known as “Nikko Bay,” but traditional leaders and government officials are working to revive the indigenous name of Ngermid.)

Even those clams living on bleached corals are pulsing color, like wildflowers in a white-hot desert. Sweeney’s ponytail flows out behind her as she nears them with her camera. They startle back into their fluted shells. Like bashful fairytale creatures cursed with irresistible beauty, they cannot help but draw attention with their sparkly glow.

Barnett makes them seem magical and perhaps they are (Note: A link has been removed),

It’s the glow that drew Sweeney’s attention to giant clams, and to Palau, a tiny republic of more than 300 islands between the Philippines and Guam. Its sun-laden waters are home to seven of the world’s dozen giant-clam species, from the storied Tridacna gigas—which can weigh an estimated 550 pounds and measure over four feet across—to the elegantly fluted Tridacna squamosa. Sweeney first came to the archipelago in 2009, while working on animal iridescence as a post-doctoral fellow at the University of California at Santa Barbara. Whether shimmering from a blue morpho butterfly’s wings or a squid’s skin, iridescence is almost always associated with a visual signal—one used to attract mates or confuse predators. Giant clams’ luminosity is not such a signal. So, what is it?

In the years since, Sweeney and her colleagues have discovered that the clams’ iridescence is essentially the outer glow of a solar transformer—optimized over millions of years to run on sunlight and algal biofuel. Giant clams reach their cartoonish proportions thanks to an exceptional ability to grow their own photosynthetic algae in vertical farms spread throughout their flesh. Sweeney and other scientists think this evolved expertise may shed light on alternative fuel technologies and other industrial solutions for a warming world.

Barnett goes on to describe Palau’s relationship to the clams and the clams’ environment,

Palau’s islands have been inhabited for at least 3,400 years, and from the start, giant clams were a staple of diet, daily life, and even deity. Many of the islands’ oldest-surviving tools are crafted of thick giant-clam shell: arched-blade adzes, fishhooks, gougers, heavy taro-root pounders. Giant-clam shell makes up more than three-fourths of some of the oldest shell middens in Palau, a percentage that decreases through the centuries. Archaeologists suggest that the earliest islanders depleted the giant clams that crowded the crystalline shallows, then may have self-corrected. Ancient Palauan conservation law, known as bul, prohibited fishing during critical spawning periods, or when a species showed signs of over-harvesting.

Before the Christianity that now dominates Palauan religion sailed in on eighteenth-century mission ships, the culture’s creation lore began with a giant clam called to life in an empty sea. The clam grew bigger and bigger until it sired Latmikaik, the mother of human children, who birthed them with the help of storms and ocean currents.

The legend evokes giant clams in their larval phase, moving with the currents for their first two weeks of life. Before they can settle, the swimming larvae must find and ingest one or two photosynthetic alga, which later multiply, becoming self-replicating fuel cells. After the larvae down the alga and develop a wee shell and a foot, they kick around like undersea farmers, looking for a sunny spot for their crop. When they’ve chosen a well-lit home in a shallow lagoon or reef, they affix to the rock, their shell gaping to the sky. After the sun hits and photosynthesis begins, the microalgae will multiply to millions, or in the case of T. gigas, billions, and clam and algae will live in symbiosis for life.

Giant clam is a beloved staple in Palau and many other Pacific islands, prepared raw with lemon, simmered into coconut soup, baked into a savory pancake, or sliced and sautéed in a dozen other ways. But luxury demand for their ivory-like shells and their adductor muscle, which is coveted as high-end sashimi and an alleged aphrodisiac, has driven T. gigas extinct in China, Taiwan, and other parts of their native habitat. Some of the toughest marine-protection laws in the world, along with giant-clam aquaculture pioneered here, have helped Palau’s wild clams survive. The Palau Mariculture Demonstration Center raises hundreds of thousands of giant clams a year, supplying local clam farmers who sell to restaurants and the aquarium trade and keeping pressure off the wild population. But as other nations have wiped out their clams, Palau’s 230,000-square-mile ocean territory is an increasing target of illegal foreign fishers.

Barnett delves into how the country of Palau is responding to the voracious appetite for the giant clams and other marine life,

Palau, drawing on its ancient conservation tradition of bul, is fighting back. In 2015, President Tommy Remengesau Jr. signed into law the Palau National Marine Sanctuary Act, which prohibits fishing in 80 percent of Palau’s Exclusive Economic Zone and creates a domestic fishing area in the remaining 20 percent, set aside for local fishers selling to local markets. In 2016, the nation received a $6.6 million grant from Japan to launch a major renovation of the Palau Mariculture Demonstration Center. Now under construction at the waterfront on the southern tip of Malakal Island, the new facility will amp up clam-aquaculture research and increase giant-clam production five-fold, to more than a million seedlings a year.

Last year, Palau amended its immigration policy to require that all visitors sign a pledge to behave in an ecologically responsible manner. The pledge, stamped into passports by an immigration officer who watches you sign, is written to the island’s children:

Children of Palau, I take this pledge, as your guest, to preserve and protect your beautiful and unique island home. I vow to tread lightly, act kindly and explore mindfully. I shall not take what is not given. I shall not harm what does not harm me. The only footprints I shall leave are those that will wash away.

The pledge is winning hearts and public-relations awards. But Palau’s existential challenge is still the collective “we,” the world’s rising carbon emissions and the resulting upturns in global temperatures, sea levels, and destructive storms.

F. Umiich Sengebau, Palau’s Minister for Natural Resources, Environment, and Tourism, grew up on Koror and is full of giant-clam proverbs, wisdom and legends from his youth. He tells me a story I also heard from an elder in the state of Airai: that in old times, giant clams were known as “stormy-weather food,” the fresh staple that was easy to collect and have on hand when it was too stormy to go out fishing.

As Palau faces the storms of climate change, Sengebau sees giant clams becoming another sort of stormy-weather food, serving as a secure source of protein; a fishing livelihood; a glowing icon for tourists; and now, an inspiration for alternative energy and other low-carbon technologies. “In the old days, clams saved us,” Sengebau tells me. “I think there’s a lot of power in that, a great power and meaning in the history of clams as food, and now clams as science.”

I highly recommend Barnett’s article, which is one article in a larger series, from a November 6, 2017 The Atlantic press release,

The Atlantic is expanding the global footprint of its science writing today with a multi-year series to investigate life in all of its multitudes. The series, “Life Up Close,” created with support from Howard Hughes Medical Institute’s Department of Science Education (HHMI), begins today at TheAtlantic.com. In the first piece for the project, “The Zombie Diseases of Climate Change,” The Atlantic’s Robinson Meyer travels to Greenland to report on the potentially dangerous microbes emerging from thawing Arctic permafrost.

The project is ambitious in both scope and geographic reach, and will explore how life is adapting to our changing planet. Journalists will travel the globe to examine these changes as they happen to microbes, plants, and animals in oceans, grasslands, forests, deserts, and the icy poles. The Atlantic will question where humans should look for life next: from the Martian subsurface, to Europa’s oceans, to the atmosphere of nearby stars and beyond. “Life Up Close” will feature at least twenty reported pieces continuing through 2018.

“The Atlantic has been around for 160 years, but that’s a mere pinpoint in history when it comes to questions of life and where it started, and where we’re going,” said Ross Andersen, The Atlantic’s senior editor who oversees science, tech, and health. “The questions that this project will set out to tackle are critical; and this support will allow us to cover new territory in new and more ambitious ways.”

About The Atlantic:
Founded in 1857 and today one of the fastest growing media platforms in the industry, The Atlantic has throughout its history championed the power of big ideas and continues to shape global debate across print, digital, events, and video platforms. With its award-winning digital presence TheAtlantic.com and CityLab.com on cities around the world, The Atlantic is a multimedia forum on the most critical issues of our times—from politics, business, urban affairs, and the economy, to technology, arts, and culture. The Atlantic is celebrating its 160th anniversary this year. Bob Cohn is president of The Atlantic and Jeffrey Goldberg is editor in chief.

About the Howard Hughes Medical Institute (HHMI) Department of Science Education:
HHMI is the leading private nonprofit supporter of scientific research and science education in the United States. The Department of Science Education’s BioInteractive division produces free, high quality educational media for science educators and millions of students around the globe, its HHMI Tangled Bank Studios unit crafts powerful stories of scientific discovery for television and big screens, and its grants program aims to transform science education in universities and colleges. For more information, visit www.hhmi.org.

Getting back to the giant clams, sometimes all you can do is marvel, eh?