HomeLatest ThreadsGreatest ThreadsForums & GroupsMy SubscriptionsMy Posts
DU Home » Latest Threads » NNadir » Journal
Page: « Prev 1 2 3 4 5 6 7 8 ... 96 Next »


Profile Information

Gender: Male
Current location: New Jersey
Member since: 2002
Number of posts: 25,533

Journal Archives

Power ideals and beauty fading in everyone's hand...

Hidden Perils of Lead in the Lab: Containing...Decontaminating Lead in Perovskite Research.

The paper I'll discuss in this post is this one: Hidden Perils of Lead in the Lab: Guidelines for Containing, Monitoring, and Decontaminating Lead in the Context of Perovskite Research (Michael Salvador,* Christopher E. Motter, and Iain McCulloch, Chem. Mater. 2020, 32, 17, 7141–7149)

When I was a kid, I worked a few years with radioactive iodine-125 to make reagents for an early and once popular form of competitive ligand binding assays; radioimmunoassay kits. The radioactive iodine came in the form of an iodide salt, and the procedure was to oxidize the iodine with a reagent called "Chloramine T," N-chlorotoluene sulfonamide, an oxidant that generates the electrophilic reagent chloroiodine and, inevitably, some free iodine, which can and does volatilize. The chloroiodine would react with aromatic rings - most typically on tyrosine in proteins, and the protein (or other standard) would be thus labeled and detectable at very low levels using a scintillating detector, but some would always escape from the test tubes in which the reactions were performed.

Although iodinations were conducted in the hood it was inevitable, especially because chromatography was generally conducted on benchtops in this lab, that surfaces in the lab would become contaminated with radioiodine, including floors and benchtops, and ultimately the result that scientists working in the lab would themselves become contaminated. Most everyone had a thyroid count after a few months, but one could minimize it by taking iodine supplements, something I encouraged among my peers.

The fun thing was that one could almost always see where and how much one was contaminated with the simple use of Geiger counter, and one could discover quite readily how effectively one's safety practices, gloving, lab coats, lead aprons were working. I had a lot of fun with this. Because I understood radiation better than most people in the lab - these were tools for biological assays after all - I generally took responsibility for handing clean up and waste disposal and I used this experience to learn a lot about contamination and decontamination, which proved useful throughout my career. (If one iodinates proteins in one's skin, one cannot wash it off of course, which is why gloves were always worn, but even these were never 100% effective.)

Of course, working with radioiodine - which is immediately detectable - is good practice for working with nasty metals, like, as is discussed in this paper, lead, which is not immediately detectable and thus is in many ways worse. The same is true of say, Covid-19 viral particles. I would recommend that anyone who is wearing gloves in situations of possible Covid exposure including exposure in the general public and who has not be trained in contamination and decontamination, take a good look at the figure I will post below.

It should be obvious that we have failed miserably to prevent the contamination of the entire planetary atmosphere with carbon dioxide (and for that matter aerosols of the neurotoxins lead and mercury released in coal burning) but that hasn't prevented humanity from doing the same thing over and over again and expecting a different result. Here I am referring to the quixotic effort to displace fossil fuels - although the focus has often drifted into a stupid and frankly dangerous effort to displace infinitely cleaner nuclear energy rather than fossil fuels - with so called "renewable energy," the most popular form being "solar energy."

The failed effort to address climate change with solar energy hasn't lacked for ever more elaborate schemes, and frankly, although I deplore the solar energy industry in general because of its most dangerous feature - it doesn't work to improve the environment - some interesting science has nonetheless resulted from the huge expense, some of which, unlike the solar industry itself, may someday have practical import.

The latest fad in solar research is in the area of perovskites, solids having the following molecular structure:

(This cartoon is found on the web pages of the Cava Lab at Princeton University.) One can see that these are octahedra embedded in cubic structures.

The most famous of the perovskites in the endless and continuously failed quest to make solar electricity produce energy on a scale that is meaningful are ternary compounds of cesium, iodine and lead. (Sometimes the cesium can be substituted with small organic ions.) There are actually people who believe that distributing lead for "distributed energy" would be a good idea.

I'm not kidding. The rationale is that "it's not as bad as coal burning" or "it's not as bad as car batteries" which is like saying "breast cancer is not as bad as pancreatic cancer."

Go figure.

Laboratory research is often dangerous and I know from experience that people can get quite cavalier about it. It's a bad idea to get cavalier. People's health can be impacted by the reagents with which they work.

Hence this paper is quite a useful reminder that, um, playing with lead base perovskites can be bad for you.

Perovskite solar cells have garnered enormous excitement over the past decade, arising from their ease of fabrication, high performance, and rapid performance improvement.(1,2) As the number of research and development groups actively engaged in this field continues to increase, the safe handling, exposure, and disposal of the toxic lead salts used in these devices becomes a more prominent issue. While students and researchers are usually familiar with the general idea that lead can be toxic, very little awareness is often demonstrated toward the potential hazards associated with lead contamination in the lab, particularly around lead-based device fabrication. This article provides guidance on how to best control lead contamination in the form of the most commonly used lead salts in the context of mainstream perovskite research that is happening today across many laboratories in the world. The procedures described herein emerged from the experience gained in our laboratories over the past several years. The text reflects our discussions with health, safety, and environment (HSE) experts, observations of exposure routes in the lab, quantitative results of lead contamination and spread in perovskite research laboratories, and interpretation on how to best contain, monitor, and decontaminate lead compounds in the form of solids (powders) and solutions. We note that this is not an all-comprehensive safety instruction bulletin but rather an attempt to highlight less-obvious dangers and offer practical solutions for researchers to consider and utilize...

...Lead(II) salts are precursors of lead-based perovskite semiconductors. In a typical perovskite research lab, spillage of trace amounts of lead powder is unavoidable. Unlike a simple spill of a benign chemical, spills of lead compounds can expose researchers to levels of lead that can be harmful.(3) Lead(II) salts can be toxic and are suspected carcinogens.(4,5) Lead can also accumulate in the body through bioaccumulation in bone and other tissues.(6) It can cause a variety of well documented health problems and can even ultimately result in death.(7) Moreover, lead salts are most commonly provided in the form of fine powders that can easily become airborne and spread across large distances in the lab. Solvents which are commonly used to prepare perovskite formulations, such as dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), can significantly exacerbate the intoxication of lead compounds as they are particularly effective in enhancing skin permeability, thus increasing the risk of absorption via dermal contact.(8) In addition, it is important to realize that contaminated clothing can also transport lead from the lab leading to secondary exposure. Therefore, controlling lead levels at the source is vital in order to reduce lead exposure.

The paper contains a nice table of "permissible" lead exposures:


The authors then make this less than reassuring statement:

Alarmingly, a recent cohort study by Lanphear et al.(12) reported an attributable fraction of blood lead levels to all-cause mortality among U.S. adults of 18%, pointing to potential health implications at levels much lower than the guidelines defined, for instance, by OSHA.(12,13) In this context, we cite text from the Association of Occupational and Environmental Clinics (AOEC): “Although the Federal Occupational Safety and Health Administration’s lead standards have provided guidance that has been beneficial for lead-exposed workers, these regulations have not been substantially changed since the late 1970s and thus are primarily based on health effects studies that are well over three decades old. There is an urgent need to revise them.”(14) As such, current regulations are outdated and do not account for the much more concentrated forms of lead (>97% purity) and its diffusivity (in the form of loose powders). Considering these limitations, we drafted procedures, which are shared here, evolving from experiences within our groups and collaborators.

The authors conduct tests using commercially available colorimetric test swabs and more quantitatively precise and accurate instrumentation, Inductively Coupled Plasma Mass Spectrometery (ICP-MS).

This table gives a flavor for the results:

They give a nice demonstration of how to change and remove one's gloves.


The caption:

Figure 1. Stepwise graphical representation of how to safely remove used gloves. The first step requires pinching the glove at the wrist level, pulling it away from the skin and then peeling it away from the hand, allowing it to turn inside out. After securing the removed glove, the ungloved hand is used to remove the other glove by sliding the fingers of the ungloved hand between the glove and the skin of the wrist and rolling the second glove down the hand. Adapted from Centers for Disease Control and Prevention.(17)Figure 1 was created by Heno Hwang, scientific illustrator at King Abdullah University of Science and Technology (KAUST).

They conduct some cleaning experiments:

The caption:

Figure 2. Probing the effectiveness of detergents/soap to remove lead from the surface of a fume hood. (A) A total of 1 mL of a perovskite precursor solution in a 4:1 mixture of dimethylformamide and dimethyl sulfoxide containing lead bromide, lead iodide, cesium iodide, methylammonium bromide, and formamidinium iodide (all with a 1.7 M concentration) was dropped on and spread across similar areas in the form of squares. The surface was blow dried using a heat gun. (B) Photograph after cleaning the right and center piece and before cleaning the left contaminated piece. The contaminated area on the left turned yellowish upon sprinkling the area with soap water (Dial soap), but lead was removed effectively after only one cleaning cycle (Figure 2C). (C) Photograph of the three purposely contaminated areas after completing the cleaning cycles described in Table 3.

The authors evaluate several commercial lead removal products, but note that the cleaning materials themselves represent a disposal problem.

They also give some scale to the production of 1 GW of lead perovskite solar cells:

In a future perspective, we emphasize that the recovery of lead as well as other hazardous materials such as cadmium, antimony, fluorine-based polymers, and other elements/components (e.g., aluminum, silver, copper, indium, gallium, tellurium, and glass) used in manufacturing solar panels is critically important from an environmental, safety, and global health perspective. A 1GW installation of perovskite solar panels would generate an estimated 3450 kg of lead waste at the end of its lifecycle (assuming a 500 nm film and 20% power conversion efficiency). In most countries, waste associated with PV panels falls under the classification of “general waste”, which may be classified as hazardous waste. In the US, for instance, there is no dedicated national program or requirement to safely dispose of solar panels. The regulations fall under the Resource Conservation and Recovery Act (RSCA), which is enforced by the US Environmental Protection Agency (EPA). The European Union (EU) was the first region to adopt PV-specific waste regulations. The EU imposes that PV module manufacturers that sell to the European market finance the costs of collecting and recycling end-of-life PV panels. This mandate is expected to create a reliable and economically viable recycling industry. The International Renewable Energy Agency (IRENA) and the International Energy Agency’s Photovoltaic Power Systems Programme (IEA-PVPS) are taking leading roles in the context of regulating the disposal of end-of-life photovoltaic panels.(21)

By way of full disclosure, the institution where this work was performed was the King Abdullah University in Saudi Arabia. One of the authors, Ian McCulloch, holds a joint appointment at Oxford. I fully expect that some people will therefore assume that the work described herein is tainted. These are the same people who apparently believe that solar panels represent an alternative to the use of petroleum. This is a widely held belief, but it has never been effectively demonstrated anywhere on this planet. It is in fact, a myth, even though well over a trillion dollars has been expended in this century on the solar energy fantasy. In this century the use of oil has proceeded - in terms of energy produced - at three times the rate of wind, solar, geothermal and tidal energy combined, the growing by 34.79 exajoules to 188.45 exajoules, the latter, again combined by 9.76 exajoules to 12.27 exajoules. 12.27 exajoules is just about 2% of world energy demand.

2019 Edition of the World Energy Outlook Table 1.1 Page 38] (I have converted MTOE in the original table to the SI unit exajoules in this text.)

If I were Saudi and wanted to make the oil industry secure, I would encourage the further expenditure of money on solar cells, since they have proved ineffective entirely at displacing dangerous fossil fuels, as demonstrated by the fact, among many similar facts, that recently the arctic has burned owing to climate change, huge tracts of Australia have burned owing to climate change, and huge tracts of the American West Coast are currently burning owing to climate change. The rise in concentrations of the dangerous fossil fuel waste carbon dioxide is accelerating, and as of 2020, has reached an annual rate of 2.4 ppm/year.

Facts matter.

The authors recommend that laboratory work with perovskites be conducted in glove boxes and the precautions be taken to monitor the egress units. They recommend that international safety standards be established for laboratories working on lead perovskite materials.

There are, by the way, methods of safely dealing with hazardous waste from cleaning materials, paper towels, for example, and gloves, about which I've done considerable reading, but to my knowledge, they are not commercially practiced anywhere.

I trust you will have a pleasant Sunday as possible while respecting your own health and safety and those of others.

Sustainable Iron-Making Using Oxalic Acid: The Concept, A Brief Review of Key Reactions...

The paper I'll discuss in this post is this one: Sustainable Iron-Making Using Oxalic Acid: The Concept, A Brief Review of Key Reactions, and An Experimental Demonstration of the Iron-Making Process (Phatchada Santawaja, Shinji Kudo,* Aska Mori, Atsushi Tahara, Shusaku Asano, and Jun-ichiro Hayashi, ACS Sustainable Chem. Eng. 2020, 8, 35, 13292–13301)

There's a rumor going around that coal is dead, often accompanied with the delusional statement that so called "renewable energy" killed it. These statements are Trump scale lies. In the 21st century, has coal proved to be the fastest growing source source of energy, growing in terms of primary energy production by more than 63 exajoules from 2000 to 2018, faster than even dangerous natural gas, which was the next fastest growing source of primary energy, having grown by 50 exajoules from 2000 to 2018, roughly 700% percent faster and 600% faster than so called "renewable energy" in this period, ignoring biomass combustion, and hydroelectricity, the former being responsible for about 1/2 of the six to seven million air pollution deaths each year, the latter having destroyed pretty much every major riverine system in the world.

2019 Edition of the World Energy Outlook Table 1.1 Page 38] (I have converted MTOE in the original table to the SI unit exajoules in this text.)

One of the reasons that coal has grown so fast in this century is that poor people around the world - who basically we pretend don't exist - have not agreed to remain desperately impoverished so rich people in the post industrial Western world can pretend that their "Green" Tesla electric cars are powered by solar cells and wind turbines.

It would be a gross understatement to say that I am "skeptical" that so called "renewable energy" will do anything at all to address climate change. Half a century of cheering for it has done zero to prevent California, Australia, and indeed even the arctic from catching fire.

My least favorite form of so called "renewable energy" is represented by the wind industry, and one of my biggest criticisms of this benighted industry is its high mass intensity, particularly with respect to its high steel requirements, coupled with the short life time on average of wind turbines, typically well under twenty years.

There is essentially no steel that is not made on industrial scale with coal, today: Coal fires convert anthracite coal into coke, with the coke being used to reduce iron, alloying it with carbon, to make steel.

That's a fact. Facts matter.

Even if no energy were produced using dangerous fossil fuels - the use of which is rising, not falling - the problem of steel would remain, although it is possible that we may, to some extent, enter the age of titanium, are well into the age of aluminum, but the electrochemical reduction of both of these metals depend on carbon electrodes made from dangerous fossil fuels, coal coke and petroleum coke respectively.

This dependence is why this paper caught my eye.

From the introduction:

Iron and steel are materials indispensable to modern society. Global crude steel production rose by 3.9% from 1.71 Gt in 2018 to 1.78 Gt in 2019, and continued growth is projected in the years to come.(1) The iron and steel industry is, however, one of the most energy-intensive industrial sectors.(2−7) CO2 emissions from this industry amounted to approximately 2.0 Gt in 2019, accounting for 24% of the total amount emitted directly from industries.(8) The majority of CO2 is generated in the iron-making process, which generally employs a blast furnace (BF). The BF is a sophisticated technology that is used to produce a massive amount of iron continuously. CO2 emissions are unavoidable during this process as the technology relies on fossil fuels, coal in particular, for reducing iron oxides in the iron ore and providing heat to maintain a furnace temperature of up to 2,200 °C.(6,9) Among all energy services and industrial processes, the iron and steel industry, which inevitably relies on fossil fuels, is considered to be in the category of “difficult-to-eliminate emissions”.(7) The development of alternative iron-making technology is thus vital to the global goal of building a sustainable society.

Extensive R&D efforts have been invested in alternative approaches to iron-making from the iron ore, which are largely classified into two types: direct reduction (DR) and smelting reduction processes.(2−6,9−12) In DR, the iron oxides in iron ore are reduced using reducing gas (H2 and CO) produced from natural gas or coal in reactors such as shaft furnaces and fluidized bed reactors. The reduction occurs at temperatures below the melting point of iron, producing so-called direct reduced iron or sponge iron. On the other hand, smelting reduction produces molten iron like a BF using a two-step process consisting of the solid-state reduction, followed by smelting reduction. The developed technologies, e.g., MIDREX for the DR and COREX, FINEX, ITmk3, and Hismelt for the smelting reduction, have been commercialized or are under demonstration.(3,6,13) The advantages of these alternative iron-making processes over BF include the lack of a need for coke, lower CO2 emissions, and lower capital/operation costs. However, they do not address the fundamental problems posed by the use of a BF because of their reliance on fossil fuels and harsh operating conditions. From this viewpoint, there are limited studies on potential sustainable iron-making methods...

There are many routes to oxalic acid with carbon dioxide as a starting material; one can come across papers along these lines regularly, some of which involve electrochemical reduction. Oxalic acid is moderately toxic, and is frequently utilized in commercial wood preservative products because it suppresses the viability of microorganisms that hydrolyze cellulose and lignin, the main constituents of wood. Famously the inability of the American Chestnut tree to synthesize oxalic acid when compared to the ability of the Chinese Chestnut to produce this biotoxin, led to the near extinction of the former. (Recently there has been promising work to insert oxalic acid generating genes into American Chestnuts.)

Oxalic acid is the simplest diacid, having the formula C2H2O4. It may be thought of as dimer formed by the elimination of two hydrogens from formic acid, the simplest carboxylic acid.

The overall scheme of this oxalic acid iron reduction scheme is shown in the following graphic from the paper:

The caption:

Figure 1. Concept of iron-making process proposed in this study. OA: oxalic acid.

The authors note that among many acids designed to solvate iron oxides - which are clearly insoluble in water - is in fact oxalic acid, although mineral acids are more commonly utilized in this process.

They write:

During leaching, iron is chelated by the organic acids and selectively removed from the material in a stable form. Among the organic acids, oxalic acid has been studied extensively and suggested to be the most effective acid for this purpose due to its high acid strength and good complexing ability...

...There are several factors affecting the rate of iron dissolution. Among them, pH of the initial solution, acid concentration, and temperature have been intensively studied.(17−24,26,28,30−32) The rate of iron dissolution is maximized when the pH of the oxalic acid solution is in the range of 2.5–3.0 because bioxalate anions (HC2O4–), which are responsible for iron dissolution, are the most abundant species in this range.(24,27,28) However, the pH of 2.5–3.0 is difficult to control with oxalic acid due to its low concentration, corresponding to 1–3 mmol/L, and, moreover, the low concentration is often insufficient for iron oxide removal. Therefore, the oxalic acid solution is typically prepared with the addition of its alkali salt as a buffering agent...

Dissolution is improved with the application of heat, which is unsurprising.

It is known that iron oxalate complexes can be reduced photochemically - this reaction has been used in actinometric devices - but the rate is slow, so the authors examine pyrolysis of the complex.

Thermal treatment of metal oxalates is an approach used to synthesize nanocrystalline metals or metal oxides. Fe(II) oxalate dihydrate is the typical precursor, and its thermal behavior has been investigated in some reports.(50−54)Figure 2 presents mass release curves for pyrolysis of Fe(II) oxalate dihydrate under a flow of N2 or 50% H2/N2, analyzed in this study. Upon heating, Fe(II) oxalate dihydrate starts to release water, forming anhydrous Fe(II) oxalate that is thermally stable up to around 300 °C. At higher temperatures, Fe(II) oxalate pyrolyzes with the release of CO and CO2 to form metallic iron, iron oxides, or iron carbides. The chemical form and composition of the iron product are significantly influenced by the atmosphere during the occurrence of pyrolysis. Although the reaction mechanism that determines the chemical form is still contested, most studies have identified FeO as the primary product during pyrolysis under an inert atmosphere, which was also confirmed in Figure 2 by the relative mass of 39.9%, corresponding to the generation of FeO, above 420 °C.

Figure 2:

The caption:

Figure 2. Mass release curves of Fe(II) oxalate dihydrate in the pyrolysis under a flow of N2 or H2/N2 (50%): sample 5 mg, heating rate 10 °C/min, and gas 300 mL/min.

The authors avoid the hand waving "we're saved!" nonsense that often accompanies popular descriptions of lab scale processes when discussing the reduction of carbon dioxide to oxalic acid:

Oxalic acid has been synthesized on a large scale worldwide. Because demand is not necessarily high, the synthetic route and feedstock used differ by countries and companies according to their situation. The employed feedstock has been sugars (e.g., starch and sucrose), CO, ethylene glycol, and propylene.(55) Alternatively, there has been no industrial process that uses CO2 as the feedstock, and only a few academic works have reported successful synthesis despite its attractiveness. This clearly shows the technical difficulty of CO2 activation in forming C–C bonds.

A robust approach to the reductive coupling of CO2 is electrochemical conversion.(56−58) For example, atmospheric CO2 is spontaneously captured and electrochemically converted into oxalate over copper complex, mimicking the natural photosynthetic transformation of CO2.(59) However, electrochemical conversion requires costly catalysts and organic solvents, which are unlikely candidates as an industrial method to produce cheap oxalic acid and iron. A recent report by Banerjee and Kanan(60) stood out in this regard, revealing the generation of oxalate only by heating cesium carbonate in the presence of pressurized H2 and CO2. The carbonate anion was replaced by formate anion from CO2. Then, the formate anion was coupled with CO2 to selectively form cesium oxalate with a yield of up to 56% (with respect to the carbonate), including other carboxylates at 320 °C and 60 bar. Nevertheless, the technical development of CO2 utilization for oxalic acid synthesis is still in its infancy.

In its infancy.

Given my personal focus on the utility of fission products, I note that hot cesium is one of the most prominent fission products, especially when freshly captured from used nuclear fuels. In addition, gamma radiation is known to produce carbon dioxide radicals, which may well accelerate this process.

But it's a very long way from here to there...

In any case, the authors experimentally (lab scale) use both photochemical and pyrolytic reduction of iron oxalate.

The following table shows the composition of the iron in each case.

XRD (X-ray diffraction) of the two processes:

The caption:

Figure 3. XRD pattern of feedstock and solid products from photochemical reduction (SSTP2) and pyrolytic reduction (SSTP3).

Scanning electron microscope (SEM) images of the product:

The caption:

Figure 4. SEM image of feedstock and solid products from photochemical reduction (SSTP2) and pyrolytic reduction (SSTP3).

In these graphics IO-A and IO-B refer to two different natural iron ores; CS refers too "converter slag" which represents iron recovered that would otherwise be waste.


The caption:

Figure 5. Iron recovery at each step of conversion.

A graphic representation of the dissolution process using oxalic acid:

All papers on processes have to make a stupid genuflection to the idea that solar energy will save the world, even though it won't:

The caption:

Figure 7. Photochemical reduction of dissolved iron with solar simulator at 180 klx and room temperature: time-dependent change of conversion to FeC2O4·2H2O and Fe2+ or Fe3+ concentration.

An attempt to build a plant around this idea would be to deliberately build a plant that is a stranded asset for large periods of a twenty four hour day, not to mention days when it rains, snows, or the sky is occluded by the smoke of uncontrolled fires because solar energy did not address climate change even after trillions of dollars and worldwide screams of cheering.

The caption:

Figure 7. Photochemical reduction of dissolved iron with solar simulator at 180 klx and room temperature: time-dependent change of conversion to FeC2O4·2H2O and Fe2+ or Fe3+ concentration.

On that score, a schematic of batch productivity:

The caption:

Figure 8. Iron productivity as functions of reaction time and iron concentration in a batch operation.

Excerpts of the conclusion and caveats against "We're saved!"

A three-step iron-making process was proposed and investigated using different types of iron-containing materials. The experimental results showed promising performance as an iron-making method. The chemical selectivity of iron dissolution and photochemical reduction enabled the obtainment of product iron with a purity of 80.5–99.7 wt % (on a metal basis) from the feedstocks consisting of 33.9–93.3 wt % iron. The highest temperature used for completing the reduction to metallic iron was only 500 °C due to the pyrolysis characteristics of Fe(II) oxalate. On the other hand, the iron dissolution step determined primarily the overall yield and purity of the produced iron. Ca and Mg reacted with oxalic acid to form water-insoluble oxalates, causing its shortage for the iron dissolution. Transition metals such as Mn were inevitably included in the produced iron. As a result, iron recovery from CS, having high contents of these unwanted metals, was limited to 15.8%. The iron recoveries from IO-A and IO-B were 91.5 and 88.3%, respectively. The proposed method also allowed for the use of powdered ore, which has not been the feedstock in conventional iron-making except for the smelting reduction. The availability of diverse feedstocks will be a great advantage considering the decreasing quality of iron ore globally...

...A consideration is necessary for particle sizes of the feedstock iron ore, Fe(II) oxalate, and iron product. In the present experiment, fine particles of feedstock with sizes below 38 μm were used to avoid possible influences of mass transfer on the iron dissolution. Fe(II) oxalates, obtained in the photochemical reduction, were also fine powders in the order of micrometers. In large-scale practical applications, technical difficulties would be found in feeding into and recovering from reactors for such small particles. Another concern is that small sizes of reduced iron product cause a low resistance to spontaneous ignition, which is also a problematic property of direct reduced iron.

The synthesis of oxalic acid from CO2 is vital to process sustainability. Direct synthesis is an emerging area of research but has a long way to go to become an industrial technology. Indirect synthesis via CO or biomass is a realistic option if a conversion system with economic and energetic rationality is found. It is also important to confirm the generation of CO2 and CO from iron-making, according to the proposed stoichiometry, and to design reactors that enable their recovery...

It's a cool paper on an area of research that I would certainly think is merited, not that anyone cares what I think.

Have a nice weekend. Please be safe and respect the safety of others.

A leading coronavirus vaccine trial is on hold: scientists react

This comes from the news section of the scientific journal Nature:

A leading coronavirus vaccine trial is on hold: scientists react

Subtitle: Scientists urge caution in global vaccine race as AstraZeneca reports ‘adverse event’ in a person who received the Oxford vaccine.

Nicky Phillips, David Cyranoski & Smriti Mallapaty Nature News September 9, 2020.

All Covid related papers and news items published by major scientific publishers are open sourced.

Enrolment in global trials of a leading coronavirus-vaccine candidate are on hold after a ‘suspected adverse event’ in a person who received the vaccine in the United Kingdom. Scientists say that it’s too soon to say what impact this might have on the global push to develop a vaccine, but that the news highlights the importance of waiting for the results of large, properly designed trials to assess safety before approving a vaccine for widespread use.

Researchers at the University of Oxford, UK, in collaboration with the pharmaceutical company AstraZeneca, are developing the vaccine, which is one of nine coronavirus vaccines in the final, ‘phase III’ stage of being tested.

Details of the adverse event, including how serious it is and when it happened, have not been reported by Oxford or AstraZeneca. But the trial’s pause comes amid concerns that US drug agencies might face political pressure to approve a vaccine before trials are completed, ahead of the US presidential election in November.

“The clinical hold shows that there are functioning checks and balances, in spite of political pressure,” says Marie-Paule Kieny, a vaccine researcher at INSERM, the French national health-research institute in Paris. “It might indeed remind everybody — even presidents — that for vaccines, safety is paramount,” she says.

Coronavirus vaccines leap through safety trials — but which will work is anybody’s guess

“I do hope that the adverse event is unrelated to the vaccine, since Oxford’s candidate seems quite promising so far,” says Florian Krammer, a virologist at the Icahn School of Medicine at Mount Sinai in New York City. The decision to halt the trial shows that the process to evaluate vaccines works, and ensures that only safe and effective therapies make it to the market, he says...

...It is the second time that administration of the vaccine has been paused in the UK, according to two people who took part in the study and to information sheets uploaded to a clinical trial registry. Previously, a participant developed symptoms of transverse myelitis, an inflammation of the spinal cord which is often sparked by viral infections, according to an information sheet given to trial participants dated 12 July. After a safety review, the trial resumed. The individual was diagnosed with an “unrelated neurological illness”...

...Adverse events are not uncommon in clinical trials, and are often unrelated to the treatment being tested, says Paul Griffin, an infectious-disease researcher at University of Queensland in Brisbane, Australia, who has conducted large clinical trials. For instance, an adverse event would include a participant being admitted to hospital for any reason, and might automatically trigger the pausing of the trial even if the admission was unrelated to the vaccine...

...Researchers have been especially worried that COVID-19 vaccines could cause an ‘enhanced disease’ when people who receive the vaccine are exposed to the virus subsequently. Animal studies and early-phase human trials of COVID-19 vaccines, including the Oxford/AstraZeneca candidate, have so far reported no signs of enhanced disease.

The Oxford vaccine is a viral-vector vaccine that harnesses a cold-causing ‘adenovirus’ isolated from chimpanzees. The chimpanzee adenovirus has been modified such that it can no longer replicate in cells, and it expresses the ‘spike’ protein that the coronavirus uses to infect human cells...

I added the bold.

The greatest tragedy in all of this is the ongoing rise of the confusion of science with politics. This is not an isolated instant limited to Covid, of course, and it is not, regrettably, limited only to the political right, although the Trump cult is the problem reified.

The Chemistry of the Class of Poisons Putin Utilized to Poison Navalny: Novichok A234.

The paper I'll discuss in this post is this one: Novichoks – The A group of organophosphorus chemical warfare agents (Marcin Kloske Zygfryd Witkiewicz, Chemosphere Volume 221, April 2019, Pages 672-682).

I came across this paper as a result of a news item in Science: How German military scientists likely identified the nerve agent used to attack Alexei Navalny (Richard Stone, Science September 8, 2020.)

An excerpt:

On 2 September, German Chancellor Angela Merkel revealed that Alexei Navalny, a Russian opposition politician, had been poisoned with a nerve agent “identified unequivocally in tests” as a Novichok—one of a family of exotic Soviet-era chemical weapons. Merkel, a chemist by training, did not reveal the nature of the tests, conducted in a military lab in Munich. But scientists familiar with Novichoks have a good idea how the toxicological sleuths went about it—and are impressed by how fast the culprit was unmasked.

Navalny fell ill on 20 August after drinking a cup of tea at a Siberian airport. He lapsed into a coma and was flown to Berlin 2 days later; in a statement yesterday, the hospital treating him said he is out of the coma and “responding to verbal stimuli.” Navalny’s supporters have accused Russian operatives of slipping poison into the tea—a charge that seems credible in light of Russia’s recent record of using toxic substances to silence critics.

Novichok A234 was the weapon of choice for settling a score with a former Russian spy, Sergei Skripal, in Salisbury in the United Kingdom in March 2018. In a botched operation, two Russian intelligence officers left a trail of evidence in the attempted assassination of Skripal, whose daughter Yulia also fell ill after exposure to A234. They survived, but a woman who later came across a perfume bottle containing the substance died.

The Salisbury scandal brought Novichoks out of the shadows. After a Russian chemist in 1992 divulged some details about the exquisitely toxic nerve agents—there are at least seven of them—the U.S. government and allies clamped down on open discussion; Novichoks were classified as secret. A234’s brazen use in the United Kingdom led to a public reckoning...

Personally, I don't think that the uncovering of Novichoks in Nalvany was particularly challenging. It is really an issue of seeing the symptoms, knowing some history, and utilizing some bioanalytical high resolution mass spectroscopy to confirm the suspicions.

I have no idea whether Vladmir Putin, who owns our "President" outright - has read a translation of Edgar Allan Poe's The Cask of Amontillado but in choosing his poisons, Polonium-210 in the case of Alexander Litvinenko, Novichok A234 in the case of Sergei Skripal, and now, for Navalny Novichok again, by using poisons to which he, and he alone, has unique access, so there can be no ambiguity about who is doing the killing, he seems to take Poe's remarks on revenge in the story seriously:

I must not only punish but punish with impunity. A wrong is unredressed when retribution overtakes its redresser. It is equally unredressed when the avenger fails to make himself felt as such to him who has done the wrong. It must be understood that neither by word nor deed had I given Fortunato cause to doubt my good will. I continued, as was my in to smile in his face, and he did not perceive that my to smile now was atthe thought of his immolation.

The full Chemosphere paper is a rather interesting review of the chemistry and history of these chemical warfare agents that are uniquely Soviet/Russian, although they got their start in Germany.

An excerpt from the text:

Organophosphorus-based chemical warfare agents (OP CWAs) are the most toxic substances amongst synthetic chemical ones. Notwithstanding the foregoing, as well as the Chemical Weapons Convention (CWC) spirit of the law (Witkiewicz et al., 1996), still exists the threat of the use of chemical warfare is almost growing day by day (Crowley et al., 2018; Guidotti and Trifirò, 2016; Kenyon et al., 2005; Mangerich and Esser, 2014; Robinson, 2008, 1998; Rogers, 2014; Simonen, 2017; Stock, 1998; Üzümcü, 2014). CWAs may be used, not only on the battlefields, during military operations, but still is growing the possibility of its terrorist's use. CWAs could be the tool for political opponents' killings. The threat is still to be expected (Croddy et al., 2011; Tucker, 2007). In March 2018 an attempt was made to murder Sergei Skripal with a new poisonous agent called Novichok. In fact, it is a group of chemical compounds with very high toxicity. The information about these substances is incomplete, often contradictory. Therefore, this paper describes the available information about this group of chemical compounds belonging to OP CWAs.

Up to the moment, in literature there is a division of OP CWA(s) into G and V (sub)groups. These groups are well descripted in the sets of articles and books, as well as are quite well described in the undisclosed military literature. In this paper we describe G and V group in general terms, with strict Novichok characterization as one of OP CWA, capable to inhibit acetylcholinesterase (AChE). Novichoks are described as A-subgroup, without clearly stating that they are organophosphorus substances with physicochemical and toxic properties similar to substances belonging to groups G and V. This is probably, due to the fact that there is no P-C binding in its molecules. However, these substances are organophosphorus compounds because its molecules contain phosphor and carbon atoms. Therefore, we believe that it is necessary to introduce the novel OP CWAs division into three subgroups: G, V and A. In this article we present a justification for this opinion.

Some history:

The chemical warfare history is probably as old as the humankind. Already in 400 BCE, during the Peloponnese War, the Sparta army used sulphur vapours against the Athens army. Later, chemical substances were used many times and in various forms during military operations. The highest victim number was caused by the chemical warfare use during World War I, between 1914 and 1918. As a result of the poisonous substances use on both sides of the conflict, 85.000 soldiers died, more than 1.2 million were permanently blinded, burnt and mentally mutilated (Delfino et al., 2009; Mangerich and Esser, 2014; Ramirez and Bacon, 2004; Sheffy, 2005; Shiver, 1929; Szinicz, 2005)...

...Nerve agents poisoning symptoms are associated with the autonomic nervous system stimulation by acetylcholine accumulation, which is not decomposed by acetylcholinesterase. The cholinesterase inhibition is the reason for this.
In addition to their immediate effects, nerve agents also have delayed effects. They take the form of psychological, neurological and cancer effects. There is also susceptibility to infectious diseases, liver disorders, pathological changes in blood and bone marrow as well as eye damage.

Nerve agents have been discovered in Germany before World War II during the development of organophosphorus pesticides. On an industrial scale, they started to be produced during the War...

...In 1936, the OP CWAs, compounds with code names G (G-group) has been discovered in Germany. On December 23rd this year, during his work on insecticides, Gerhard Schrader discovered the first chemical compound belonging to the G group. It is nowadays known as tabun. After a drop of tabun spilled on the laboratory table, Schrader and his assistant had myosis, dizziness and shortness of breath. It took them three weeks to recover. The Wehrmacht had been interested in the discovery and further hidden research was carried out in a military laboratory. The tabun was initially coded Le 100 and later Trilon 83. In 1938 in the Schrader's team was discovered compound with code-name T-144 and Trilon-46, known as sarin. This name is derived from the names of the first developers: Schrader, Ambros, Ritter and Linde. Sarin has been shown to be about 10 times more toxic than tabun.
Through research on tabun and sarin at the Heidelberg Institute, Kuhn and Henkel received a soman whose name is derived from the Greek word 'to sleep' or the Latin 'mace'...

... The tabun test production has been started before the World War II beginning. The test production process and equipment used in it were complicated. The industrial scale production during WW II was located in Dyhrenfurth, currently Rokita Chemical Plant in Brzeg Dolny (Poland). Approximately 3000 employees were engaged at the plant. Of these, several hundred were injured and at least several dozen died. About 10,000 to 30,000 tons of tabun were produced before the plant was taken over by the Soviet army and was probably moved to Dzerzhinsk, Russia. The slave labour force was employed to take part in tabun production. One of the inmates was prisoner of the concentration camp at the Dyhrenfurth plant, professor Andrzej Waksmundzki; in the next years outstanding chemist, analyst and chromatographer...

"Milestones" in the development of chemical warfare agents, table 3 from the text:

Structures of some known nerve agents, including Sarin, which was used for a terrorist attack in Japan in 1995, and again in Syria, by Putin's client, in 2018:

The caption:

Fig. 1. OP CWAs structural formulas for G-group nerve agents: tabun, sarin, soman, ethyl sarin, chlorosarin, cyclosarin, and DFP.

Some more text:

Novichoks has been discovered in the former Soviet Union as the development work on the third and fourth generation of chemical warfare agents (Averre, 1995; Kloske, 2018; Mirzayanov, 2009). These works included inter alia, the construction of binary munitions and delivery systems. The main research centre for CW was the State Institute for Scientific Research on Organic Chemistry and Experimental Technologies. Initially, only reconstructive research was being conducted on the works carried out in western laboratories. At the beginning of the 1970s, the highest authorities imposed on scientists the development of poisonous fourth generation substances on their own. These substances had to be:

undetectable using standard chemical detection instruments fitted to the NATO member states armies in the 1970s and 1980s;
able to penetrate the enemy soldier's body despite the application of individual protection measures;
safer than previous generations of CWA during storage and combat use preparation;
not mentioned in the lists (also precursors) of Chemical Weapon Convention.

As a result of these assignments, phosphonates and phosphates containing amidine and guanidine fragments in the molecule - Fig. 5 and formaldehyde oxime - Fig. 6, were invented. It is also worth mentioning that in the late 20th century, the German company Bayer developed an organophosphorus pesticide derivative, called Phoxim, whose use in agriculture was banned in 2007 due to its strong toxic properties - Fig. 7.

Figures 5, 6, and 7:

The caption:

Fig. 5. General OP CWAs chemical structures for amidine & guanidine X = F or S-alkyl; R1 = O-alkyl (phosphate derivative) or alkyl (phosphonate derivative); R2, R3, R4, R5 = H, alkyl, phenyl, -CN.

The caption:

Fig. 6. General organophosphorus derivatives of formaldehyde oxime formula; X1 = F; X2 = any halogen, CF2NO2, CN; X3 = any halogen, CN, R = O-alkyl (phosphate derivative) or alkyl (phosphonate derivative).

The caption:

Fig. 7. Phoxim structural formula

The programme under which Novichoks were developed was codenamed FOLIANT. The first public article on Novichok appeared in the weekly Moskovskie Novosti in 1992, on the eve of Russia ratifying the Chemical Weapons Convention. The authors were two chemists - Lew Fiodorov and Vil Mirzayanov. According to the authors, the Russian military-chemical complex was using funds received from the West for the implementation of disarmament agreements to build a modernised potential for conducting a chemical war. The authors revealed information allegedly in connection with their concern for the environment. They were working on measuring the concentration levels of harmful substances in facilities and outside facilities associated with the chemical weapon programme. These measurements were to prove whether foreign intelligence agencies could detect traces of BST production. The results of the measurements showed that the levels of toxic agents in the environment were about eighty times higher than the maximum safe concentrations. For unknown reasons only one article author - Mirzayanov was arrested and accused of state secrets treason

And so on...

Nice guy, the guy who owns your "President..."

Interesting paper, I think, scary but interesting.

I am not, for the record, in favor of banning chemistry, but like any technology, chemistry has a huge potential for abuse.

Have a nice, and where possible, safe, day.

Another Great Day For Renewable Energy in California.

This data comes from the CAISO website, Accessed 19:30 PST 09/09/20:

Big "Percents" today around noon, despite all the smoke:

Fabulous work "by 2020." They certainly addressed climate change by 2020:

Weekly average CO2 at Mauna Loa

Week beginning on August 30, 2020: 411.59 ppm
Weekly value from 1 year ago: 408.82 ppm
Weekly value from 10 years ago: 387.59 ppm
Last updated: September 9, 2020

Thank goodness they'll be closing their last nuclear plant "by 2024."

One never knows what could have happened at that nuclear plant, which has "only" been producing 2,246 MW of electricity all day long, constantly, in a single building. That sucks.

Heckuva job! Heckuva job!

So green, or, um, brown, or well, it's "by 2020," in any case.

We're doing great!!!

...what does that hand desire...

Editorial: Circularity. What's the Problem?

This editorial perfectly summarizes my personal outlook on environmental issues, so much so that I wish I had written it.

It's in the current issue of ACS Sustainable Chemistry and Engineering. Regrettably, I think it's behind a paywall:

Circularity. What’s the Problem? (Paul T. Anastas, ACS Sustainable Chem. Eng. 2020, 8, 35, 13111)

Some brief excerpts:

Every reader of this journal wishes to solve societal and ecological problems. Otherwise, they would be content with choosing to study scientific challenges that see no shame in irrelevance...

...Some of these historically derived yet lingering problems are receiving a tremendous amount of focus today. These include the following:

Achieving durability in materials without consideration for persistence in our bodies and the biosphere, especially our oceans.

Achieving convenience of data and information access while our electronics are dispersing critical metal and metalloid elements.

Achieving unprecedented crop yields while contaminating water resources with agricultural chemical runoff...

...The most recent example that must be examined is the very hot topic of the circular economy whose conceptual construct of moving toward cycling our material economy and eliminating waste is undeniably compelling. So what must be done in order to ensure this elegant theory is put into equally elegant practice? Perhaps a noncomprehensive list may include the following:

Ensure that energy, which is so often left out of the discussions of materials circularity, is integrated as the essential component that it is.

Ensure that the nature and character of the materials and energy within these cycles are considered at least as important as the stock, flows, and quantities of them.

Ensure that the timeframes and widely differing commercial lifespans of various materials streams are considered while attempting to build these circular constructs.

Ensure that the actual act of separation/isolation/purification of complex material streams—that can have in many cases, in itself, negative environmental, economic, and societal impacts—does not dwarf the original problem attempting to be solved.

Ensure that a circular economy construct definitionally envisions continuity and predictability of specified material flows that recognizes we are living in a dynamic world that will not become static in order to service circularity...

...The circular economy is an elegant concept that can contribute to a more sustainable society if its problem statement is thoughtfully designed and implemented wisely, with forethought for unintended consequences such as those outlined above. Alternatively, a half-designed circular economy would be yet another example of good intentions gone awry...

The part I have put in bold, is the most important of all the many insightful statements this editorial contains.

Without highly dense energy, utilized to maximal efficiency to assure equitable distribution, all is lost.

The issues in this editorial summarize perfectly what we must do to build a sustainable society, and delineate how far, exactly, we are from it.

Suspended Particle−Water Interactions Increase Dissolved 137Cs Activities in Typhoons (Fukushima).

The paper I'll discuss in this post is this one: Suspended Particle–Water Interactions Increase Dissolved 137Cs Activities in the Nearshore Seawater during Typhoon Hagibis (Hyoe Takata,* Tatsuo Aono, Michio Aoyama, Mutsuo Inoue, Hideki Kaeriyama, Shotaro Suzuki, Tadahiko Tsuruta, Toshihiro Wada, and Yoshifumi Wakiyama, Environ. Sci. Technol. 2020, 54, 17, 10678–10687)

The 137Cs isotope being discussed here is that released by the much discussed nuclear meltdowns at the Fukushima Dai-ichi nuclear power plant. It discusses the behavior of radioactive cesium released by the reactors when their containment buildings were damaged by a hydrogen explosion. The hydrogen was generated by a steam/zirconium interaction: Zr(s) + 2H2O(g) <-> 2H2(g) + ZrO2 solid. This reaction takes place at very high temperatures, temperatures that were experienced in the reactor core - zirconium is a key element in the structure of reactor cores as well as in the cladding of fuel elements - when the back up diesel generators that were supposed to keep the reactor cool during shut down failed when inundated with seawater.

Seawater killed about 20,000 people, but this is far less interesting to most people than the escape of radioactivity from the reactor, just as the 19,000 people who will die today, and died every day since March of 2011, and will die for an indefinitely defined people, from air pollution is not as interesting as the escape of radioactive materials from the reactors.

Cesium is a cogener of two elements that are essential to all living things, sodium and potassium. Physiologically cesium tends to behave very much like potassium, as does it's lighter cogener, rubidium. (Lithium is also a cogener of these elements.) Salts of these elements are all highly soluble in water, but cesium, and to a lesser extent, rubidium, tend to adhere to the surfaces of minerals commonly found in soil. The adsorption of cesium on to soil particles is a key point in the paper under discussion.

Natural cesium is not radioactive; natural rubidium and potassium are (slightly) radioactive owing to the naturally occurring long lived isotopes Rb-87 and K-40.

All human beings, indeed all living things, contain significant radioactivity as a result of the presence of potassium as well as its cogener rubidium, albeit to a lesser extent.

A common unit among many to quantify radioactivity is the "Bequerel," named for the scientist who discovered radioactivity in 1897. The Bequerel (Beq) is defined as one radioactive decay per second in any radioactive substance. The mBeq, the milliBequerel, which appears prominently in the paper is strictly speaking, 1/1000th of this amount. I mBeq is the number of decays that will take place in 1000 seconds. It is useful to think of mBeq as its reciprocal for values of less than 1000 mBeq; the reciprocal is the number of seconds (on average) that will pass before a decay is observed.

It can be shown that a 70 kg human being, owing to the natural radioactivity associated with potassium, will have about 4250 Beq of radioactivity in their flesh. There will also be some radioactivity associated with rubidium, which is not essential to human beings or other life forms but which is nonetheless almost always found in human and other living flesh. Rubidium can and does behave like potassium to some extent, particularly in instances of hypokalemia, too little potassium, where it can serve to ameliorate the shortage. One sometimes hears from a certain class of people that "there is no safe amount of radioactivity." These people are - there's no polite way to put this - idiots. Potassium is an essential element. Without potassium, one dies. It is thus essential that a healthy 70 kg human being contain around 4250 Beq of radioactivity.

In October of 2019, the Fukushima region was struck by a typhoon, and this paper is about the behavior of cesium which had adhered to soil particles after release from the reactor in this typhoon, as well as in high flow events in the rivers near the reactor.

From the introduction:

More than half of the radiocesium (i.e., 134Cs and 137Cs) released as a result of the Fukushima Dai-ichi nuclear power plant (FDNPP) accident was deposited and/or released into the nearshore ocean.(1−4) That radiocesium, however, moved via dilution and advection into the open ocean because the FDNPP is located at a coastal site, and the adjacent coastal waters are directly connected to the North Pacific Ocean. The decrease in radiocesium activity in water column in the offshore area to 0.1 Bq/L within 1 year(5,6) led to a rapid decline in Cs levels in marine organisms.(7−9)
In 2019, 8 years after the accident, 137Cs activities in the waters >30 km offshore from Miyagi to Chiba prefectures on the Pacific Ocean side of Japan were approaching the 2010 pre-accident levels (<2.4 mBq/L), and 134Cs, which has a half-life of 2.06 years, is now almost undetectable because four half-lives have passed.(10)

In contrast, 137Cs activities in nearshore waters in the vicinity of the FDNPP and within 10 km of Fukushima and neighboring prefectures(11) are still higher than those before the accident.(12) It is known that longshore currents flow primarily from the north of the Pacific Ocean side of Japan,(13) so 137Cs activities in nearshore waters were statistically higher in the south than to the north of the FDNPP from 2014 to 2016.(14) Furthermore, the quantification of the fluxes of 137Cs associated with direct release from the plant, re-entry of 137Cs from sediments through the submarine groundwater discharge (SGD), and fluvial inputs have indicated that direct discharge is the principal source of 137Cs that has maintained the relatively high 137Cs activities in the coastal waters during the 2 year period of 2014–2016.(6,14−16) However, the contribution of the ongoing release has declined. A sharp decline in radionuclide releases with water from the FDNPP after completion of a frozen soil wall in 2015 and of the water treatment system (e.g., pumping up the polluted water)(17) was probably the result of a reduction in the flow from the FDNPP because the flux from the plant has been decreasing since then.(15) Hence, it is likely that the constant flux of 137Cs from rivers, the catchment areas of which are contaminated, now plays a more important role in the activities of 137Cs in coastal areas in addition to the re-entry of 137Cs from sediments through SGD, which increases dissolved 137Cs in coastal waters of the wide area from both north and south of the FDNPP.(16)...

...It has been recognized that dissolved Cs+ is the dominant form of cesium in the ocean, but cesium is found in both particulate and dissolved forms in coastal areas.(21) Although riverine radiocesium includes both dissolved and particulate forms, a high proportion of radiocesium in rivers is associated with particles.(22,23) In particular, the heavy rainfall from typhoons, which cause devastating floods over wide areas, could result in contaminated surface soils being swept into rivers. In fact, the particulate fraction of radiocesium accounted for almost 100% of the radiocesium in the particulate phase after the typhoon of September 2011, and the fluxes of particulate radiocesium accounted for 30%–50% of the annual radiocesium flux from inland to coastal ocean regions in 2011.(22) In addition to elucidating the dynamics of dissolved radiocesium in the marine environment, it is necessary to understand the dynamics of its particulate phase and the interactions between dissolved and particulate radiocesium when river water mixes with seawater in the coastal areas, in which salinity changes markedly from 0 to 34.

There are several studies available in the literature concerning the behavior of radiocesium in river–sea systems: Although much of the radiocesium carried by rivers is in particulate form (i.e., adsorbed onto suspended particles), the salinity increase along the system results in the desorption of this radiocesium from the riverine suspended particles, thus increasing radiocesium activity in the dissolved phase in coastal seawaters (Figure 1).(24−32)...

... The goal of this study was therefore to explore the distribution of radiocesium in dissolved and particulate phases in the downstream reaches of rivers and the nearshore and offshore waters south of the FDNPP shown in Figure 2 with their catchment areas and mean 137Cs inventories in Table 1 (see detailed information on sampling sites and methods in the Supporting Information). Particularly, we focus on to what extent the desorbed fraction of riverine radiocesium contributed to the elevated levels of 137Cs in the dissolved phase in the nearshore areas after the heavy rainfall from typhoon Hagibis in the middle of October 2019...

Figure 1:

The caption:

Figure 1. Schematic diagram of riverine suspended particle behavior (light brown arrows) along the southward-flowing coastal current (blue arrow) including high radiocesium water from the plant in the coastal zone of Fukushima Prefecture from the FDNPP to the south of the prefecture. The dark blue arrow indicates the ground water discharge. The box at the right hand indicates sources of (1) the FDNPP site local sources (that can come in many forms, from GW at the site to tank leaks to over land contamination/rain inputs, etc.), (2) the more disperse release from GW associated with beach sands (Sanial et al.(16)), and (3) rivers and desorption. Riverine suspended particles introduced into the marine environment provide dissolved radiocesium through the desorption process while drifting in the longshore current.

The caption:

Figure 2. Sampling stations in the vicinity of the FDNPP (red circles: stations in downstream reaches of rivers; light blue circles: nearshore stations; dark blue circles: offshore stations). Area α is the area within a 30 km radius of the FDNPP. Area β is the area outside of Area α. The spatial distribution of 137Cs inventory is based on the third airborne survey by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) in 2011; the 137Cs inventory data were obtained from the website of the Japan Atomic Energy Agency; Airborne Monitoring in the Distribution Survey of Radioactive Substances (https://emdb.jaea.go.jp/emdb/portals/b1010301/).

Table 1:

The following figure refers to large volumes of water passed through a weighed dried 0.45 micron filter, designed to collect suspended particles, drying and weighing and then performing the counts of radiation obtained. The details can be found in the supplemental information which is open and free at the web page of the full paper.

The caption:

Figure 3. Distribution of (A) temperature (Temp.), (B) salinity (Sal.), (C) suspended particles, and (D) particulate 137Cs in rivers (Tomioka, Kido, Asami, Natsui, Fujiwara, Same, and Binda rivers) and adjacent nearshore (S1–S6) and offshore (O1–O12) stations. Gray circles indicate the geomean value in each station. Errors are not shown in this figure for readability but are listed in Table S1.

From the following graphic, one can estimate how much river water one would need to drink to get a single Beq of cesium-137.

The caption:

Figure 4. Distribution of (A) dissolved 137Cs, (B) particulate 137Cs, (C) percentage of particulate 137Cs in total 137Cs, and (D) Kd values in rivers (Tomioka, Kido, Asami, Natsui, Fujiwara, Same, and Binda rivers) and adjacent nearshore (S1–S6) and offshore (O1–O12) stations. Gray circles indicate the geomean value in each station. Errors are not shown in this figure for readability but are listed in Table S1.

Radioactivity as a function of distance to the shoreline.

The caption:

Figure 5. Variation in the river–nearshore–offshore system as a function of distance from the shoreline (0 km) in (A) 137Cs in particles, (B) dissolved 137Cs, (C) particulate 137Cs, and (D) Kd values. Negative distances indicate the fluvial area; positive distances indicate the offshore area. Errors are not shown in this figure for readability but are listed in Table S1.

The caption:

Figure 6. Light blue and blue bars indicate the estimated desorbed 137Cs activity (DesCsdis in eq 2) and observed dissolved 137Cs activity in which estimated desorbed activity has been deducted. Blue bars could originally include seawater through ongoing release from the FDNPP facility and re-entry through SGD. (A, B, C) Fraction (f) in eq 2 = 0.03 and (D, E, F) f = 0.3. Graphs on the left side of each figure are the pre-typhoon period in 2019 (high-river-flow condition from June to September). Graphs on the right are from the post-typhoon period. Dissolved 137Cs activity for offshore in (A) and (D) is mean value of station O1–4 (6.6 mBq/L). Dissolved 137Cs activity for offshore in (B), (C), (E) and (F) is mean value of station O5–12 (3.2 mBq/L). An asterisk (*) indicates a 137Cs concentration of 12 mBq/L at station TD-9 (37°20.0′N,141° 4.3′E) sampled on 14 Nov. 2019. Double asterisks (**) indicate a 137Cs concentration of 11 mBq/L at station M-G0 (37°5.0′N,141°8.4′E) sampled on 2 Nov. 2019. Both of these values were provided by the Nuclear Regulation Authority (https://radioactivity.nsr.go.jp/en/list/292/list-1.html).

The overall amount of cesium-137 released into the ocean is rather prodigious, on the order of GBq/day. A unit of radioactivity the Curie (Ci) is roughly equal to the number of decays in one gram of radium, = 3.7 X 10^(10) Beq, 37 megaBeq. Thus amounts approximating a Curie/day leach into the ocean.

However, the ocean contains vast amounts of potassium. I have done some calculations elsewhere to show how much radioactivity is present in the ocean from potassium alone: How Radioactive Is the Ocean?. In this calculation, I showed that the potassium associated radioactivity of the ocean was approximately 530 billion curies, or 2 X 10^(22) Beq, 20 zetaBeq.

I trust you've having a pleasant Labor Day afternoon.

Florida City Replaces Images of Black Former Fire Chiefs with White Faces. Two Fired...

Boynton Beach removes 2 officials after public art mural replaced images of black former chiefs with white faces

BOYNTON BEACH - After a public art project based on photographs replaced the images of two black former department chiefs with white faces, City Manager Lori LaVerriere removed Matthew Petty, the city’s fire chief, and fired Debby Coles-Dobay, the city’s public arts manager.

LaVerriere wrote in a Saturday afternoon statement that she “concluded a preliminary investigation regarding the inappropriate decisions made by City employees.”

Coles-Dobay wrote Saturday to the Post that she “was pressured to make this artwork change by the Fire Chief and his staff, as the City well knows.”

Coles-Dobay did not elaborate.

The removals are effective immediately. Petty, who initially faced demotion, agreed to resign, LaVerriere said in an email statement.

The mural, which the city unveiled this month, erased the image of Boynton-born and -raised Latosha Clemons, who was the city’s first and only black female firefighter and deputy chief.

She scaled and led the department ranks for about 24 years until retiring effective March 1.

The mural also erased the face of Glenn Joseph, the city’s former fire chief and the first black firefighter in Boca Raton’s department.

Officials removed the public art project a day after it was unveiled.

“I’m hurt. I’m disappointed. I’m outraged,” Clemons said Friday. “It’s been my heart and soul and my lifeblood to serve in the community where I grew up ... this is beyond disrespect and I basically want to know why it happened...”

Another day in the life in these increasingly vile times...

Go to Page: « Prev 1 2 3 4 5 6 7 8 ... 96 Next »