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How do chemists solve the problem of plastic waste conversion



plastic waste conversion

Researchers have developed a new method to turn a mixture of several types of plastic waste into a valuable raw material and then use it to produce fuel or plastic.

We tend to lump all plastics together, but as you’ve probably noticed, water bottles, milk cans, egg cartons, and credit cards are made of different materials when throwing recyclables in the recycling bin. When they arrive at the recycling center, the plastic must be separated. This process can be slow and costly and ultimately limit the types of materials that can be recycled and the amount of recycling.

A new way for converting plastic waste

Now researchers have developed a new process that can convert a mixture of several types of plastic into propane, a simple chemical building block that can be used as fuel or turned into new plastics or other products. This process works because although their exact chemistry can vary, many plastics have a similar basic building block: they’re made of long chains of mostly carbon and hydrogen.

Along with environmental protections and policies, reengineering recycling can help prevent some of the worst damage caused by plastic wastes.

More than 400 million tons of plastic are produced worldwide every year. Of this amount, less than 10% is recycled, about 30% remains in use for a while, and the rest either goes to landfills or the environment or is burned.

Plastics are one of the most effective climate change factors: their production accounted for 4.3% of global greenhouse gas emissions in 2019. Recycling keeps plastics out of landfills and oceans, and finding new ways to produce building blocks for plastics can also help reduce greenhouse gas emissions. Our goal is to eventually see plastic waste as a valuable raw material, says Julie Rohrer, a postdoctoral researcher in chemical engineering at the Massachusetts Institute of Technology and one of the latest study’s authors.

One of the main advantages of the new approach Rohrer and his colleagues developed is that it works on two common plastics: polyethene and polypropylene.

Produce propane from plastic waste

plastic waste conversion

A mixture of plastics that make up milk bottles and containers is fed into a reactor, and propane is produced. This approach has high selectivity; propane makes up about 80% of the final product gases. “It’s exciting because it’s a step towards the idea of being cyclical,” Rohrer says.

Rohrer and his colleagues use a catalyst with two components to reduce the energy required to break down plastic: cobalt and a porous sand-like material called zeolite. Researchers aren’t yet sure exactly how the compound works. Still, Rohrer says it’s likely that the selectivity results from the pores in the zeolite limiting the reaction sites of the long molecular chains in the plastic. At the same time, the cobalt prevents the zeolite from becoming inactive.

This process is still far from being ready for industrial use. Currently, the reaction is done on a small scale and needs to continue to be economical.

Researchers are also looking at what materials to use. Cobalt is more common and less expensive than other catalysts they’ve tested, such as ruthenium and platinum, but they’re still looking for better options. Rohrer says that a better understanding of how catalysts work could allow them to replace cobalt with cheaper, more abundant ones. Rohrer says the ultimate goal of a thoroughly mixed plastic recycling system is not far-fetched.

Read more: Discovering secrets of human genome by AI

However, achieving this vision requires reforms. Polyethene and polypropylene are simple chains of carbon and hydrogen, while some other plastics contain other elements, such as oxygen and chlorine, which can challenge chemical recycling methods. For example, suppose polyvinyl chloride (PVC), widely used in bottles and pipes, gets into the system. In that case, it can deactivate or poison the catalyst and produce toxic gas byproducts, so researchers still need to find other ways to manage it. Find that type of plastic.

Other scientists are also looking for different ways to recycle mixed plastics. In a study published in October in Science, researchers used a chemical process alongside genetically engineered bacteria to break down a mixture of three common plastics.

Chemical oxidation

The first step involves chemical oxidation, which breaks the long chains and produces smaller molecules with oxygen attached to them. According to Shannon Stahl, one of the study’s authors and a chemist at the University of Wisconsin, this approach is practical because oxidation acts randomly on a wide range of materials.

As a result, plastics are oxidized to produce products that can then be consumed by bacteria engineered to feed on them. Researchers could create new plastics, such as nylon forms, by changing the bacteria’s metabolism.

Allie Werner, a biologist at the National Renewable Energy Laboratory and one of the authors of the study published in Science, says the research is still ongoing. In particular, researchers are trying to better understand the metabolic pathways bacteria use to make products to speed up the process and produce more significant amounts of valuable substances. This approach could potentially be used on a larger scale, as oxidation and engineered bacteria have become ubiquitous: the petrochemical industry relies on oxidation for millions of tons of material each year, and microorganisms are used in pharmaceuticals and food processing industries.

As scientists like Werner and Rohrer work on ways to recycle plastic, there are opportunities to rethink how we deal with massive amounts of plastic waste. “It’s a challenge that society is well-equipped to deal with,” Rohrer says. He notes that recently many researchers have turned to work on the optimal recycling of plastic.


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Air pollution control in South Korean style




Air pollution control in South Korean style

Air pollution control in South Korean style. Air pollution is one of the most important problems in the field of environment, which is the cause of a significant number of deaths worldwide. In recent years, South Korea has taken various solutions to deal with air pollution, many of which are based on technological advances.

Air pollution control in South Korean style

In this article we’re going to examine the air pollution control in South Korean Style. Clean air is one of the priorities of all societies in the world, and it has been raised as one of the national priorities in South Korea. For this reason, the country has initiated urgent measures to protect the health of its citizens from air pollution. Among these measures, we can mention serious dealing with pollutants, increasing vegetation, abandoning diesel engines, and moving towards a sustainable transportation system.

In this day and age, breathing clean air has become a privilege that most people find difficult to enjoy after pollution reaches alarming levels, especially in cities. Due to the health problems caused by air pollution, governments around the world are working to eliminate it.

Air pollution is the most important environmental crisis that causes more than seven million premature deaths every year. To make things clearer, considering fresh air as an advantage means that 90% of people breathe dirty air and face the risk of developing asthma, heart disease, and lung cancer. Just as air pollution affects human health, it also affects the health of the planet, and many factors of air pollution are also caused by climate change.

It is obvious that this phenomenon is an acute problem in urban environments and it seems that it is more severe in some countries than others because it fits with the lifestyle of the people and the nature of the economy of each country. For example, South Korea saw one of the highest levels of air pollution, especially in its capital city of Seoul, which between 2009 and 2013 had the highest average concentration of toxic particles in the air compared to major capital cities such as Paris and London.

Experts estimate that this level of air pollution was responsible for 16 percent of deaths in Seoul in 2010, and levels of toxic particulate matter “PM2.5” there reached double the internationally recommended amount. These particles penetrate deep into the lungs, heart, and blood vessels and pose the greatest risks to human health.

During the COVID-19 pandemic and the resulting quarantine, the concentration of air pollutants in South Korea decreased by 27%. However, the rift caused by the pandemic cannot hide the reality that South Korea is famous for. This fact is fine dust or “yellow dust”. The yellow dust storm carries harmful particles such as sulfur, carbon monoxide, heavy metals, and other carcinogenic substances. These particles do not only affect South Korea but also other East Asian countries. For this reason, the need for solutions to save the future is felt.

Therefore, the South Korean authorities are trying to fulfill their commitment to reduce air pollution by taking advantage of their superiority in the field of technology. This perspective paved the way for the birth of many qualitative innovations. In this regard, the South Korean government created the “Comprehensive Fine Dust Management Program”, which seemed to be the most ambitious plan. The aim of this plan was to reduce the emission of PM2.5 particles by 35.8% in 2022.

Among these measures, the South Korean government compiled a list of areas that have schools, kindergartens, or facilities for the elderly, and designed extensive measures to control greenhouse gas emissions and turn them into clean areas as quickly as possible. These measures included limiting the use of old diesel vehicles and reducing working hours at polluting facilities. The South Korean government also announced plans to plant trees close together along rivers and roads to direct air into the city center.

In addition, Seoul announced that it will ban diesel vehicles from all public sector and mass transit fleets by 2025.

To protect South Korea’s future, the country’s officials have decided to install air purifiers in classrooms across the country and subsidize the use of liquefied petroleum gas (LPG) fuel in school buses, which is harmful to the environment. They deliver less to the environment.

Read More: What is mazut and what are its disadvantages for humans and the environment?

Air pollution control in South Korean style

Forests in the direction of the wind

The South Korean government recently announced that it plans to increase the extent of forest areas in the country’s capital by 2025. This is one of the latest government projects to cool and clean the air in the Seoul metropolis by expanding forest areas. The first phase of this project was completed in 2021.

Air pollution control in South Korean style

The main goal of this project is to create so-called “wind paths” that contain trees and connect the mountains around Seoul to the inner city areas full of buildings. According to Seoul officials, fresh air from the mountains can be channeled into the city, which often suffers from trapped heat. As a result, the temperature level and air pollutants are reduced.

The second phase of the project will expand the number of trees planted in the first phase to two urban areas in the south and north of Seoul. The process of tree planting will be followed during the years 2024 to 2025.

By 2030, Seoul officials hope to increase green space by 30 percent and dedicate 80 percent of inner-city trips to sustainable modes of transportation such as walking, cycling, and public transportation.

An army of robots against air pollution

As robots are an integral part of South Korea’s technology landscape, 5G-equipped autonomous robots have begun to circulate in industrial complexes to monitor air quality and provide real-time air quality data. For example, six automated robots rotate around the clock in an industrial complex that is about 50 years old, working with a control tower and 20 weather monitoring stations. In 2021, the telecommunications company LG Uplus collaborated with the city of Junju in South Korea to demonstrate an air monitoring system using automated robots and air quality measuring equipment in this industrial complex. The information collected in the work process of the robots is used for urban management.

Air pollution control in South Korean style
Robots equipped with various sensors can detect unusual phenomena such as fire or smoke to prevent accidents. The collected information about air quality is used to create a large database and improve the quality of life.

In September 2020, LG Uplus demonstrated a 5G-connected autonomous robot at an oil refinery in Seosan. The robot used 5G connectivity and satellite-based routing methods to navigate around the refinery.

Drones that fight air pollution

While robots monitor environmental impacts on the ground, drones also measure air quality and monitor emissions of greenhouse gases and toxic substances in the construction and industrial sectors, as well as beach pollution for up to 20 minutes. They monitor four kilometers away.

Air pollution control in South Korean style
As soon as any of the drones detects a high concentration of pollutants, it sends a warning to the control center so that the inspectors go to the desired location and check the situation there and the compliance of its management with the rules and regulations. If any violation is observed, the official of the center will face administrative fines and legal accountability.

South Korea’s first air quality monitoring satellite

South Korea’s Ministry of Science and Information Technology announced that it will provide its residents with data on air quality and seven types of air pollutants. The data comes from the country’s environment satellite, which was launched in 2020, so there is no need to rely on foreign satellites.

Air pollution control in South Korean style

In an important step to investigate the world’s air quality, South Korea successfully launched its satellite called “Cheollian 2B” into the earth’s orbit. This is the first satellite of a triple network that will eventually cover Asia, North America, and Europe. This satellite was launched into Earth orbit on February 18, 2020, by the “Ariane 5” rocket of the “Arianespace” company from the “Guyana Space Center” in France.
A “Geostationary Environment Monitoring Spectrometer” (GEMS) is located on the Keolian 2B satellite. It is designed to improve early warning of hazardous pollution events across the Asia-Pacific region and to monitor long-term climate change.

During its 10-year mission, the Geostationary Environmental Monitoring Spectrometer will monitor the concentration of chemicals such as nitrogen dioxide, sulfur dioxide, formaldehyde, ozone, and other airborne particles. It is expected that this device will identify the source of PM2.5 fine particles flowing into South Korea for the first time by observing fine particles and dust in East Asia.

A new material that absorbs pollution precursor gases

“South Korea Institute of Civil Engineering and Construction Technology” (KICT) has made significant progress in responding to this major air pollution problem. The researchers of this institute have designed an innovative material that is designed to absorb nitrogen oxide and sulfur dioxide gases. These two substances are vital precursors for fine dust.

This new material works efficiently at room temperature, offering an energy-efficient alternative to traditional methods that require high energy and temperature.

The core of this innovation lies in a ceramic nanocomposite material made of sodium manganese oxides. This material uses a dual absorption and oxidation mechanism and effectively converts nitrogen oxide and sulfur dioxide gases into less harmful sulfate and nitrite ions.

One of the significant advantages of this material is its renewability, which allows recycling and repeated use through simple chemical methods.

Dr. Jiyeol Bae, the head of this research group, highlighted the importance of this development and said: With the development of these new nanomaterials, it is now possible to implement a system that can reduce the number of particulate matter precursors in urban environments with a cost-effective method. All these efforts help the public to enjoy clean and healthy air.

Despite this promising progress, there are challenges facing researchers, including production scalability, cost considerations for widespread application, and integration with current pollution control infrastructure. These challenges are critical to moving beyond laboratory success to real-world practical application.

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The discovery of a “lost world” belonging to a billion years ago




The discovery of a “lost world” belonging to a billion years ago. Newly discovered biomarker traces indicate the existence of a new group of previously unknown organisms called “protosteroids” that ruled complex life on Earth about a billion years ago.

The discovery of a “lost world” belonging to a billion years ago

According to AI, scientists have discovered ancient microorganisms that lived between one and 1.6 billion years ago. These creatures probably lived in marine environments.

It seems that the more we learn about the evolution of life, the more mysteries we uncover. In new research, fossils of unknown creatures have been discovered, which probably belong to about 1 to 1.6 billion years ago. These tiny organisms, known as protostole biota, lived in a world with much less oxygen than the present atmosphere and lived in the waterways of our planet.

These organisms, which belonged to the family of eukaryotes, had a complex cell structure with mitochondria and a nucleus, and they were very different from today’s eukaryotes such as animals, plants, and amoebas, and they were adapted to the needs of their environment.

Read More: The world’s oldest DNA dating back 2 million years, was discovered

These ancient organisms, which were discovered by scientists from the Australian National University (ANU) and the Helmholtz Society (Helmholtz) from German research centers, extended the current record of fossil steroids to 1.6 billion years (from 800 million). Another remarkable achievement lies in the way this discovery was made.

As Jochen Brocks, a professor at the Australian National University and one of the study’s first authors, explained, the scientists first had to find what they were looking for, using a combination of methods to “convert a variety of modern steroids into their fossil equivalents.” They were drawing. This allowed them to find overlooked traces of fossilized fat molecules inside a 1.6-billion-year-old rock at the bottom of the ocean near Australia’s Northern Territory.

Perform discovery

Dr. Benjamin Nettersheim of the University of Bremen and the other first author of the study explained how to determine where early organisms were found. Their goal, he says, is to trace the molecular remains of early organisms as far back as possible in Earth’s history.

He explains: “We knew from previous research how and where on Earth to find these precious molecular traces of early life on Earth.” There are only a few places in the world where ancient sediments are not buried deeper than a few kilometers and have never been warmed to such an extent that the diagnostic ecological information of key biological biomolecules is completely destroyed by heat and geological metamorphic processes.

The discovery of a "lost world" belonging to a billion years ago

One such place where diagnostic molecular fossils still exist is in northern Australia. As Dr. Nettersheim explained, the sedimentary rocks there have undergone very little change over 1.64 billion years of geologic history.

The discovery of a “lost world” belonging a billion years ago

To find these missing fossils, scientists had to develop new search patterns in the lab and then began finding fossil steroids in almost all rocks with biomarkers between 800 million and 1.6 billion years ago. According to Netersheim, of these, only bacterial hopanoids were known.

But these are not fossil cholesterols, but biosynthetically more primitive versions of them, he explained.

Now we have found fossil derivatives of these molecules. We think they probably derive in part from our very early eukaryotic ancestors, which must have been much more widespread and ecologically important than previously thought.

Changing our understanding of evolution

In response to the question of how this discovery affects our knowledge of evolutionary processes, Netersheim stated: “If our interpretation is correct that molecular fossils mainly originate from our early eukaryotic ancestors, it means that our early ancestors, which are the most Marine environments between 1.6 billion and about 800 million years ago still belonged to the stem of the eukaryotic tree.

This means that it was during the Tonian period, about 800 million years ago, that modern types of eukaryotes such as red algae and heterotrophic eukaryotes and so-called protists such as ciliates increased, and this is ecologically important on a global scale.

What caused their extinction?

The researchers believe their findings will improve our understanding of the major change that took place during the Tonian Period, a time known from about 1 billion to 720 million years ago. Netersheim believes that both the dramatic increase in eukaryote fossil diversity and the appearance of the first modern sterol fossils following the 800 million years of exclusively early sterols during that period produced a significant transformation of marine ecosystems on a global scale that should have led to extinction. These creatures have become ancient.

It is possible that early protosterol biota became extinct or, more likely, was marginalized by environmental disturbances during this period, he says. Their extinction may have been due, for example, to the emergence of modern eukaryotes and changes in atmospheric oxygen concentration or nutrient regimes.

Search for other ancient creatures

Now that they have identified some microorganisms from a billion years ago, scientists are looking to find more. They attempt to reconstruct ancient ecosystems and the evolution of early life as recorded in the rock record in as much detail as possible.

Their study titled “The Lost World of Complex Life and the Late Emergence of the Eukaryotic Crown” is published in the journal Nature.

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Climate change and tsunamis that will come from Antarctica




Climate change

Climate change and tsunamis that will come from Antarctica. A new study warns that climate change could trigger giant, deadly tsunamis from Antarctica, as sediment slippage beneath the Antarctic seafloor could trigger these massive tsunamis as oceans warm.

Climate change and tsunamis that will come from Antarctica

Climate change could trigger giant tsunamis in the Southern Ocean by triggering underwater landslides in Antarctica, a new study warns. Antarctica is a continent at the south pole of the earth. This continent is the coldest place on earth and more or less its entire surface is covered with ice.

Antarctica is the fifth largest continent on Earth after Asia, Africa, North America, and South America, but it has the least human population among all continents. It also has the highest average height, the lowest average humidity, and the lowest average temperature among all the continents of the world.

Read More: How does air pollution destroy our sense of smell?

More than 80% of the freshwater reserves of the planet are located in Antarctica. In this continent, nearly 30 countries have nearly 70 research bases, of which 40 are annual or permanent bases and 30 are summer bases.

Now, by drilling in sediment cores hundreds of meters below the seabed in Antarctica, scientists found that during previous periods of global warming (3 million years ago and 15 million years ago), loose sedimentary layers were formed and slid to send huge tsunami waves to the coast of South America, New Zealand.

As climate change warms the oceans, researchers think it’s possible that these tsunamis will occur again.

In a statement, Jenny Giles, a lecturer in hydrography and ocean exploration at the University of Plymouth in the UK, said in a statement: “Undersea landslides are a major hazard with the potential to cause tsunamis that could lead to loss of life.

” He added: “Our findings show how we need to urgently increase our understanding of how global climate change affects the stability of these regions and the potential for future tsunamis.”

For the first time in 2017, researchers found evidence of ancient Antarctic landslides in the eastern Ross Sea. Beneath these landslides are layers of weak sediments filled with fossilized marine organisms called phytoplankton.

Scientists returned to this area in 2018 and drilled deep into the seabed to extract sediment cores. These excavations are done by sinking long and thin cylinders into the earth’s crust, which reveal the geological history of the region layer by layer.

By analyzing these sediment cores, the scientists found that the weak sedimentary layers formed during two periods, one about three million years ago during the warmth of the mid-Pliocene period and the other about 15 million years ago during the favorable climate of the Miocene period.

During these periods, the waters around Antarctica were three degrees Celsius warmer than today, which led to an explosion of algae populations that, after dying, filled the seabed with rich, slippery sediment, making the region prone to landslides.

During the subsequent cold climate and Ice Age, these slip layers were covered by thick layers of sand, said Robert McKay, director of the Antarctic Research Center at Victoria University of Wellington and chief scientist of the International Ocean Exploration Program Expedition 374, which extracted sediment cores in 2018. The bulk was covered by glaciers and icebergs.

The exact trigger of past underwater landslides in the region is not known for certain, but researchers have found the most likely cause to be the melting of glacier ice due to global warming. The end of Earth’s periodic ice ages caused the ice sheets to shrink and retreat, lightening the load on Earth’s tectonic plates and pushing them back up in a process called isostatic rebound.

After the formation of enough weak sedimentary layers, the continental growth of Antarctica triggered earthquakes that caused the coarse sand above the sliding layers to spill out from the edge of the continental shelf, which caused landslides and tsunamis.

The scale and size of ancient ocean waves are unknown, but scientists point to two undersea thrusts that generated massive tsunamis and caused significant loss of life. The first was the Grand Banks tsunami in 1929, which created waves 13 meters high and killed about 28 people on the coast of Newfoundland, Canada, and the second tsunami in Papua New Guinea in 1998, which created waves 15 meters high and killed 2,200 people.

Considering that many layers of sediment are buried under the Antarctic bed and the glaciers above the water are also slowly melting, the researchers warn that if their melting really caused tsunamis in the past, landslides and tsunamis in the future may occur again.

Those same layers still exist on the outer continental shelf, says McKay. So it’s a starting point for more of these thrusts to occur, but the big question is whether the trigger for these events is still ongoing.

He added: “We consider isostatic rebound as a logical potential driver, but it could be a random failure or climate change in ocean currents eroding sediment at key locations on the continental shelf that could cause this to happen.” These are things we can use computer models to evaluate in future studies.

This study was recently published in the journal Nature Communications.

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