Garbage saved

Chapter 1 Trash can be saved!
Eco-friendly plastic made from milk

Plastic Technology Eco-friendly Degradable Milk
Plastic was once considered a wonder material.They're still ubiquitous, but not as popular as they used to be.That's because they're very stable and long-lasting (not easy to degrade) -- two attributes that credit them to begin with.Persistence is not a desirable characteristic for things that are meant to be thrown away, so much plastic is used in (manufacturing) packaging and single-use items that many people now view common petrochemical plastics as nuisances and threats.

Biodegradable alternatives are being sought.David Schiraldi of Case Western Reserve University in Ohio and colleagues have found one possible alternative.They're going back in history, repurposing the raw material that was used to make the first piece of so-called plastic: milk.

What they really mean is to utilize casein - the most abundant protein in milk. In 1889, a French chemist named Jean-Jacques Trillat discovered that if casein was treated with formaldehyde, the result was a hard and shiny substance that could be used as a good substitute for materials such as ivory and turtle shell.Everyone was so enthusiastic about the new material that even Queen Mary herself ordered several ornaments made of this material.However, this casein-based plastic is too brittle for everyday use.It was eventually replaced by modern petrochemical plastics, and its production ceased entirely in the 70s.

However, the idea of ​​repurposing the material has not been completely abandoned.The material is mostly protein, so it can be digested and degraded by bacteria—a property that is now considered an advantage—as long as its structural weaknesses can be overcome. Dr. Schiraldi's approach does just that: using a silicate clay called sodium montmorillonite as the backbone to hold the plastic together.

Sodium montmorillonite can be freeze-dried into a spongy material called an aerogel.Aerogels are notoriously brittle.But that's because most of their structures are hollow.In fact, people sometimes call it the nickname "solid smoke."This brittleness belies its underlying hardness.Filling the airgel's pores with plastic can compensate for the airgel's brittleness, and conversely, the clay molecular network in the aerogel prevents the plastic from cracking.So the researchers thought that if they mixed casein with clay and added glyceraldehyde (replacing the toxic formaldehyde used in older plastics), they might make something really useful.

To test this idea, the team mixed a casein solution with glyceraldehyde and sodium montmorillonite, stirred vigorously to remove air bubbles, and then frozen it at minus 80°C.Once frozen, the material was placed in a freeze dryer for four days to remove moisture, followed by curing in an oven at 80 °C for 24 hours.

The researchers report in the journal Biomacromolecules that their new material is comparable in stiffness, strength and compressibility to expanded polystyrene -- a common packaging material now used by many Junkyard headaches.However, unlike expanded polystyrene, the new material will degrade once it is discarded.A preliminary experiment showed that the new material degrades 18 percent within 20 days in a dump-like environment.Maybe the queen's brooch will degrade, but it's more useful that way.

Oyster mushrooms growing on diapers
waste disposal diaper oyster mushroom garbage environmental protection safety
Disposable diapers, although the English meaning of its name is "disposable", but its disposal is a long-standing problem.Studies of landfills have shown that it can take centuries for them to fully decompose.But Aletia Vazquez Morairas of the Autonomous Metropolitan University in Mexico City thinks she has found a way to speed up the process.

As she and her colleagues describe in "Waste Disposal," growing the right type of mushrooms on diapers can decompose 90% of them within two months.After four months, they will be completely degraded.She said that although the plectrum in question, also known as the oyster mushroom, is not tasty, it is safe to eat.To prove it, she actually tasted it herself.

The edible value of Pleurotus ostreatus is one of the reasons why she chose it for the experiment.This ingredient is often used for frying and is often added to soups.Another reason is that oyster mushrooms are widely used for so-called "mycore mediation" - the use of fungi to clean up litter.For example, it's already gaining traction on agricultural waste such as wheat and barley straw, and industrial waste like coffee grounds and tequila wine residue.Dr. Vazquez Morairas and colleagues are trying to expand the culinary scope of oyster mushrooms.

It has nothing to do with whether a diaper has been used or not.Even clean diapers end up in landfills for a long time.The main component of diapers is cellulose, which is an annoying stubborn substance.However, oyster mushrooms growing in the wild on dead or dying trees will properly secrete enzymes that break down cellulose.And since 50 billion diapers are thrown away every year in Mexico alone, there must be plenty of these materials waiting for their mycelium to decompose.

The idea, and what might be sold or eaten, may be controversial, but it's not absurd.The diapers used by the researchers had only urine stains and no feces.Urine from healthy humans is sterile and Dr Vazquez Morelas steam sterilizes the diapers to ensure safety.Such a treatment will also kill the nasty bugs in the feces, if any, so growing oyster mushrooms on treated diapers should theoretically be safe to eat.

Indeed, overcoming this subjectively distasteful element may be an insurmountable hurdle to selling oyster mushrooms grown in diapers, and the expense of steam sterilization may be unrealistic.However, the success of such "sclerotin degradation" does not depend on selling its products.It's worth it just to get rid of the tough waste that would otherwise haunt us indefinitely.And as for the fungi themselves, Dr. Vazquez Morairas comments, "At least in Mexico, they're much cleaner than most vegetables you can find in the market."

Build Cheap Houses From Scrap

Waste slag brick clay green house cost
Building homes and offices out of toxic waste sounds like a pretty weird idea.However, if Ana Andrés at the University of Cantabria in Spain does it, it could become commonplace.Dr Andres and her colleagues suggest in Industrial and Engineering Chemistry Research that the humble brick doesn't have to be made entirely of pure clay.Instead, close to 30% by weight can be replaced with slag - the toxic goo left over from making steel.

Its technical name is Waelz slag, which is mainly composed of silica, but it is not popular because it is also rich in toxic metals such as lead and zinc.So dealing with it safely is already a big problem.And waste utilization is nothing short of a miracle.But that's exactly what Dr. Andres suggests.A series of experiments she has conducted in the past have shown that this is not only achievable, but would make bricks cheaper and more environmentally friendly.

Previous reports have shown that pottery clays mixed with other materials leave the integrity of the porcelain unscathed, and that the molecular structure of certain ceramics can act as a trap for toxic heavy metal atoms.After reviewing previous studies, she started researching. She wondered if mixing brick clay with Waelz slag would have the same effect for pottery, so she started experimenting.The answer she found was that they still apply.Even if 20-30% of the composition is slag, the effective mechanical properties of the brick are still intact.And the bricks of this composition will not leak.

To test their conclusions, Dr Andres and her team ground the bricks into a powder, soaked the powder in water, stirred it with a special machine for several days, and even tried dissolving them in nitric acid.Its pollutants remain inside the bricks, motionless.In addition, adding slag to the clay reduces the amount of carbon dioxide emitted per brick during brick production by a third, as less clay is now required than some wood pulp was added before the clay was fired Meaning less wood pulp is needed.Its cost also falls because slag is free, whereas clay costs money.

Of course, there are also some problems for customers.Whether people will want to live and work in buildings that are actually waste dumps is an open question.But for those who want to promote eco, what better way to "build" their environmental credentials than literally "build" an eco-friendly house?
Wool absorbs oil, very reliable

environmental technology wool oil spill recycle
Biella, in northwestern Italy, is a center for wool mills and home to luxury clothing brand Zegna.But a group of merchants in Biella came up with an idea that had nothing to do with fashion and collections.They want to take advantage of the oil-repelling and water-repelling properties of wool and use wool to absorb spilled oil.They came up with the idea after the deepwater oil rig accident, thinking that using wool would be more effective than absorbing oil spills in the gulf of mexico with swells, chemical dispersants, etc.

In 2011, Tecnomeccanica Biellese, an engineering company that provides machinery for the wool industry, took an experimental approach to explore how well wool absorbs oil.The experimental result is that its effect is surprisingly good.Coarse wool (the cheapest variety with a fiber diameter of 25 to 40 microns) can absorb ten times as much dense oil (refined oil similar to crude oil).Besides that, used wool can be wrung out of oil and recycled.In fact, even if the wool absorbs oil ten times in a row, with an average of 15 to 20 seconds each time, its oil absorption capacity will not be affected.

The next step in the plan is to put the experiment into practice and form a system for collecting oil.The businessmen, dubbing the project the Wool Cycle Ecosystem, received permits in March for oil-absorbing equipment that can be installed on ships to deal with small oil spills or in larger ship-mounted systems Used to resolve large spills.

The manager of Tecnomeccanica Biellese, Mario Pronl, said the oil suction system on board will use a built-in motor, while the ends of the pipes will guide the oil to the wool covered in the sea.After the ship passed the oil spill area, the oil-soaked wool would be transported up the movable ramp and collected in the ship.When the fleece is on the moving ramp, the water droplets attached to it are shaken dry.The wool sent to the ship is squeezed and used again.

Mr. Prouner estimated that it would cost close to ten thousand dollars to install a meter-long conduit to load a tonne of wool.These are enough, and the ideal situation can recycle at least one thousand tons of oil.In practice, he believes, about a thousand tons of wool would be needed to clean up the million barrels of oil spilled by deepwater drilling.Thousands of tons of wool cost a lot of money for a large company like Big Oil.Plus, it would be a gold bucket for shearers.

Clean water with iron, convenient and simple

pollution iron technology environmental protection water source metal
Iron atoms in water are generally considered a source of pollution.However, Luke Daly, director of the Ferrate Technology Processing Institute in Orlando, Florida, plans to reverse that perception.Instead of polluting water, he would use an unusual chemical form of the iron atom to purify water.

Iron is part of the periodic table of chemical elements and is also known as a transition metal.Like all metals, iron atoms react with other elements, releasing electrons to form positively charged ions.But transition metals release different numbers of electrons under different circumstances, thus forming ions that carry different numbers of positive charges.Typically, iron atoms lose 2-3 electrons.But in ferrate (which is a compound of iron atoms, oxygen atoms, and non-transition metals such as nanoatoms, calcium atoms), it loses 6 electrons.This makes ferrate extremely reactive, which is the activity Mr. Daly hopes to unearth.

First, ferrate is a strong oxidizing agent.That is, they are capable of destroying bacteria and viruses and can quickly break down organic molecules.Second, they are also coagulants and flocculants, attracting other chemicals in the water (including those dissolved financials) and forming precipitates that are effortlessly removed.In addition, when its mission is over, the iron ions in ferrate will also precipitate in the form of iron oxide, and after filtration, it will be clean water.

Previously these wonder substances were not used as water purifiers because their reactivity made them unstable and difficult to store.Thomas Waite, a theoretical scientist at the Florida Institute of Technology (for which the Ferrate Technology Processing Institute utilizes his research), jokes that in his early studies, the world's supply of ferrate was in his lab cupboard.

The trick played by ferrate technology treatment is to use ferrate on-site instead of transporting it off-site for reuse.The company's "ferrate system" is to use three cheap raw materials - bleach, ferric chloride and sodium hydroxide, to manufacture sodium ferrate and calcium ferrate, and make its price, in the equivalent oxidation effect Look, comparable to water cleaners like chlorine and ozone.

Mr Daly said a machine small enough to carry in a pickup truck could produce enough ferrate to purify 7500 million liters of water a day.The system is currently being tested at two plants in Florida.If all goes well, the first commercial ferrate system will be up and running.

(End of this chapter)