China Introduces Measures to Reduce Non-biodegradable and Disposable Plastics

It’s piled up in landfills. It clutters fields and rivers, dangles from trees, and forms flotillas of waste in the seas. China’s use of plastic bags, containers and cutlery has become one of its most stubborn and ugliest environmental blights.

Actions to Drastically Reduce Use of Disposable Plastic Items

• So the Chinese government has introduced measures to drastically cut the amount of disposable plastic items that often become a hazard and an eyesore in the country, even deep in the countryside and in the oceans.
• Among the new guidelines are bans on the import of plastic waste and the use of nonbiodegradable plastic bags in major cities by the end of this year.
• Other sources of plastic garbage will be banned in Beijing, Shanghai and wealthy coastal provinces by the end of 2022, and that rule will extend nationwide by late 2025.

Serious and Systematic Efforts

Previous efforts to reduce the use of plastic bags have faltered in China, but the government has indicated that, this time, it will be more serious and systematic in tackling the problem.

“Consumption of plastic products, especially single-use items, has been consistently rising,” said an explanation accompanying the new guidelines, which were released by the environment ministry and China’s chief industrial planning agency. “There needs to be stronger comprehensive planning and a systematic rollout to clean up plastic pollution.”

The plan is likely to be welcomed by many Chinese, who have become increasingly worried about polluted air, water, soil and natural surroundings. But it could be a hard sell for a society used to the convenience of online retailers and couriers who deliver hot meals and packages swaddled in plastic.

Although people in China generally generate less plastic waste per capita than Americans, almost three-quarters of China’s plastic waste ends up in poorly managed landfills or out in the open.

Environmental campaigners in China welcomed the effort to reduce plastic use, though some said it was not strict or detailed enough. Others raised doubts about the government’s ability to develop and promote substitutes for nonbiodegradable plastics that linger in soil, waterways and oceans for decades, even centuries.

Given the severity of China’s pollution problems, greater urgency is needed, said Chen Liwen, a founder of China Zero Waste Villages, which promotes recycling in rural areas.

“It’s certainly better than nothing,” she said, adding, “For disposable products — disposable plastic bags or many disposable food utensils — they should be outright banned.”

Tang Damin, a campaigner in Beijing for Greenpeace East Asia, said in emailed comments that while “Beijing is addressing the problem seriously and pushing reusable containers as the right solution,” the policy would be far more effective with incentives like deposit return programs.

The Chinese government appears to think that companies and consumers need time to get used to life with much less single-use plastic.

Even wealthy economies have moved gingerly to ban plastic bags. Last year, New York State approved a ban on most single-use plastic bags that is to take effect on March 1, making it only the second state after California to impose such a prohibition.

China’s plan for ending reliance on throwaway plastic sets out three phases until 2025. The restrictions start in bigger cities like Beijing and Shanghai, then move to smaller cities and towns, and lastly to villages.

By the end of the year, the guidelines say, China will ban disposable foam plastic cutlery. Shops, restaurants and markets in major cities will have to stop using nonbiodegradable plastic bags by that deadline, and restaurants and food vendors nationwide will have to stop using straws made from nonbiodegradable plastic.

China’s package delivery sector will have more time to adjust. By the end of 2022, couriers in Beijing, Shanghai and wealthy coastal provinces will have to stop using nonbiodegradable plastic packaging, tape and single-use sacks woven from plastic. By late 2025, that ban will extend nationwide.

The policy’s effects may not be immediately visible, said William Liu, a senior consultant in Shanghai for Wood Mackenzie, which advises businesses about chemicals, energy and related sectors.

“But going forward,” he said in an email, “as the ban rolls out to more cities and substitute materials gain traction, China’s polyethylene consumption will be impacted.”

One sizable obstacle — given the size of China’s consumer market, the ubiquity of plastic and the amount that ends up being dumped — is the foam plastic food containers that most restaurants use for takeout orders and that are rarely reused.

Orders sold online through Alibaba, JD.com, Meituan and other Chinese e-commerce outlets often arrive wrapped in multiple layers of plastic, apparently reflecting vendors’ fears that customers will reject dented or soiled deliveries. Chinese courier services used nearly 25 billion plastic bags for deliveries in 2018, according to an industry estimate cited by Workers’ Daily and other Chinese news outlets.

“The levels of environmental protection and recycling will really upgrade only if the entire supply chain follows through,” said Zheng Yixing, the founder of the Helihuo Environmental Technology Company in Beijing, which promotes commercial recycling.

The government said it would consider blacklisting companies that flout the plastic bans. The cooperation of the big online retail companies will be crucial, said Mr. Tang, the plastics campaigner.

Source: The New York Times

New 18-carat Lightweight Gold Based on Polymer Latex and Protein Fibers

ETH researchers have created an incredibly lightweight 18-carat gold, using a matrix of plastic in place of metallic alloy elements. Leonie van ’t Hag has set to create a new form of gold that weighs about five to ten times less than traditional 18-carat gold. 

The conventional mixture is usually three-quarters gold and one-quarter copper, with a density of about 15 g/cm3. That’s not true for this new lightweight gold, its density is just 1.7 g/cm3. And nonetheless it is still 18-carat gold. 

Light Weighting Gold Using Polymer Latex

Instead of a metal alloy element, van ’t Hag, Mezzenga and colleagues used protein fibers and a polymer latex to form a matrix in which they embedded thin discs of gold nanocrystals. In addition, the lightweight gold contains countless tiny air pockets invisible to the eye. Gold platelets and plastic melt into a material that can be easily processed mechanically.

The Process to Develop the New Gold

• They added the ingredients to water and created a dispersion.
• After adding salt to turn the dispersion into a gel, next they replaced the water in it with alcohol.
• Then they placed the alcohol gel into a pressure chamber, where high pressures and a supercritical CO2 atmosphere enables miscibility of the alcohol and the CO2 gas.
• When the pressure is released, everything turns it into a homogeneous gossamer-like aerogel.
• Heat was applied afterwards to anneal the plastic polymers, thus transforming the material and compacting into the final desired shape yet preserving the 18-carat composition.

  Adjustable Hardness and Color

  
  The researchers can even adjust the hardness of the material by changing the composition of the gold. They can also replace the latex in the matrix with other plastics, such as polypropylene. 
  
  Since polypropylene liquifies at some specific temperature, “plastic gold” made with it can mimic the gold melting process, yet at much lower temperatures. 
  
  Furthermore, the shape of the gold nanoparticle can change the material’s colour, “nanoplatelets” produce gold’s typical shimmer, while spherical nanoparticles of gold lend the material a violet hue.
  
  “As a general rule, our approach lets us create almost any kind of gold we choose, in line with the desired properties,” Mezzenga says.

  Applications in Watchmaking and Electronics

  
  Mezzenga points out that, while the plastic gold will be in demand in the manufacture of watches and jewelry, it is also suitable for chemical catalysis, electronics applications or radiation shielding. The researchers have applied for patents for both the process and the material.
  
  Mezzenga’s scientists had already made a name for themselves some time ago with the lightest gold in world – gold that weighed so little it could float atop cappuccino froth. “But the material was too unstable and couldn’t be worked. This time we set ourselves the clear goal of creating a lightweight gold that can also actually be processed and used in most of the applications where gold is used today” Mezzenga says.
  
  Source: ETH Zurich

Mealworms Can Easily Degrade Toxic Additive-containing Plastics: A Stanford Study

A new Stanford study shows mealworms can eat Styrofoam containing a common toxic chemical additive and still can be safely used as a protein-rich feedstock for other animals.

Natural Breakdown of Chemicals in Mealworm’s Gut

The study is the first to look at where chemicals in plastic end up after being broken down in a natural system – a yellow mealworm’s gut, in this case. It serves as a proof of concept for deriving value from plastic waste.

“This is definitely not what we expected to see. It’s amazing that mealworms can eat a chemical additive without it building up in their body over time.” said study lead author Anja Malawi Brandon, a PhD candidate in civil and environmental engineering at Stanford.

In earlier work, Stanford researchers and collaborators at other institutions revealed that mealworms, which are easy to cultivate and widely used as a food for animals ranging from chickens and snakes to fish and shrimp, can subsist on a diet of various types of plastic.

“This work provides an answer to many people who asked us whether it is safe to feed animals with mealworms that ate Styrofoam”, said Wei-Min Wu, a senior research engineer in Stanford’s department of civil and environmental engineering who has led or co-authored most of the Stanford studies of plastic-eating mealworms.

Feeding HBCD Containing Styrofoam to Mealworms

Brandon, Wu and their colleagues fed Styrofoam or polystyrene to the mealworms. Styrofoam is a common plastic typically used for packaging and insulation, that is costly to recycle because of its low density and bulkiness. It contained a flame retardant called hexabromocyclododecane, or HBCD, that is commonly added to polystyrene.

The additive is one of many used to improve plastics’ manufacturing properties or decrease flammability. HBCD can have significant health and environmental impacts, ranging from endocrine disruption to neurotoxicity. Because of this, the European Union plans to ban HBCD, and U.S. Environmental Protection Agency is evaluating its risk.

Mealworms in the experiment excreted about half of the polystyrene they consumed as tiny, partially degraded fragments and the other half as carbon dioxide. With it, they excreted the HBCD – about 90 percent within 24 hours of consumption and essentially all of it after 48 hours. Mealworms fed a steady diet of HBCD-laden polystyrene were as healthy as those eating a normal diet. The same was true of shrimp fed a steady diet of the HBCD-ingesting mealworms and their counterparts on a normal diet. The plastic in the mealworms’ guts likely played an important role in concentrating and removing the HBCD.

The researchers acknowledge that mealworm-excreted HBCD still poses a hazard, and that other common plastic additives may have different fates within plastic-degrading mealworms. While hopeful for mealworm-derived solutions to the world’s plastic waste crisis, they caution that lasting answers will only come in the form of biodegradable plastic replacement materials and reduced reliance on single-use products.

“This is a wake-up call. It reminds us that we need to think about what we’re adding to our plastics and how we deal with it,” said Brandon.

Source: Stanford University