Composting biodegradable plastics can control plastic pollution.

Plastic is an important basic material that can be found everywhere in our lives, but its unregulated use can put some pressure on the ecological environment. R...

Apr 07,2020 | Annie

Plastic is an important basic material that can be found everywhere in our lives, but its unregulated use can put some pressure on the ecological environment. Relevant work deployment starts from the things that ordinary people live, and ordinary people can participate in plastic pollution control and contribute to ecological environmental protection.

1. What is the impact of the national deployment of plastic pollution control on the lives of our ordinary people? Which products can be used and which cannot? There are many kinds of plastic products, why does the country ban the use of these categories in the first place?

According to the relevant national deployment requirements, by the end of this year, people living in municipalities directly under the Central Government, provincial capital cities, single-listed cities should pay attention to, for example, supermarkets, pharmacies, bookstores and other places, catering packaging take-away services, various exhibition activities can not use non-degradable plastic shopping bags; in prefecture-level cities above the built-up areas, scenic dining catering services can not use non-degradable disposable plastic knives and forks and spoons; the national catering industry can no longer use disposable plastic straws, but we can also use roll bags, plastic bags, garbage bags, milk, drinks and other food overwrap straws.

Since the implementation of domestic waste separation, most plastic waste has been reasonably recycled and disposed of, such as recycling, landfill, incineration, etc. However, the closed waste recycling system is difficult to eco cutlery avoid the leakage of some plastic waste into the natural environment, where disposable plastic products are relatively difficult to recycle and leak. Such as waste plastic shopping bags, etc. Basically mixed into the domestic waste disposal system, about half of them enter the landfill. These plastic waste with domestic waste into landfills takes a long time to fully degrade, there is a great risk of environmental leakage; and then, for example, catering units used in food service disposable non-degradable plastic knives, forks, spoons, disposable plastic straws, easy to mix into the kitchen waste, to kitchen waste anaerobic fermentation and other subsequent resource processing and utilization difficulties. Therefore, banning and restricting the use of this part of plastic products that can easily leak into the natural environment can reduce the increase of plastic products that leak into the environment. Even if they leak into the environment, they can be degraded in natural environmental conditions and will not cause long-term environmental pollution.

2. After some plastic products can't be used, what else can we use? Are these alternatives environmentally friendly?

When we actively participate in plastic pollution control, we can't use some plastic products in our life, but some alternatives can be used. Such as supermarkets, pharmacies, bookstores and other places, we can use environmental protection bags, paper bags and other non-plastic products and biodegradable shopping bags; in food establishments, we can use straw-free drink cups, biodegradable plastic tableware, bamboo and wood tableware, etc.. In food and beverage places, we can use straw-free drinking cups, biodegradable plastic tableware, bamboo and wood tableware, etc.; it will also facilitate our life.

For example, biodegradable plastic products, the products after degradation are mainly carbon dioxide converted from organic carbon, microbial organic dead bodies, mineralized inorganic salts, etc. , harmless to the environment; for example, cloth bags are durable and can be recycled for multiple uses. The raw material of paper bags is wood, can also be used many times. Are environmentally friendly bags, harmless to the environment.

3. What is biodegradable plastic?

From the perspective of environmental protection, degradable plastic is a material that can be completely degraded under specific conditions or natural environment, that is, in the soil, sand, compost or anaerobic digestion or water, and eventually can be completely degraded to environmentally harmless material of a polymer material. The degraded environmentally benign substances include carbon dioxide or/and methane, water, mineralized inorganic salts and nascent materials (e.g. dead microorganisms, etc.). In short, a degradable plastic is a plastic that can naturally degrade in the environment into small molecules that do not pollute the environment and cause harm and secondary pollution. At present, degradable polymers mainly include PLA, PBAT, PBS, PBSA, PCL, PPC, PGA, PPDO, etc.

4. Can degradable plastics only degrade under composting conditions? Will they degrade in the process of use?

It is wrong that degradable plastics can only be degraded under composting conditions. Due to different species and different chemical structures, degradation process of degradable plastics under different conditions is different. Composting is only one of the conditions for degradation. Most biodegradable plastics will degrade in natural environments such as soil, freshwater or seawater, and eventually be completely broken down by microorganisms into environmentally harmless substances. For example, materials such as PBAT, PCL, and PHA can be completely degraded in as early as 6 months under suitable conditions such as compost, soil, and seawater. Although PLA materials degrade faster under composting conditions, they can be completely degraded within six months, but degradation can also occur in natural environments such as soil and seawater. For example, in field trials of biodegradable mulch films made of PBAT and PLA materials in Yunnan and Xinjiang, the film degradation was very obvious in the year of testing, and the film was completely degraded in the second year after the crops were harvested and the soil was tilled. In addition, chemical recycling of monomers such as PLA, PBAT, PCL, and PHA can also be carried out by alcoholysis, acid-base degradation, etc.

In general, the degradation conditions of degradable plastics include light, oxygen, heat, water, biology and microorganisms. Especially for microorganisms, the degradation process is essential with the participation of plastic being broken down into small molecules such as carbon dioxide and water, which are harmless to the environment. Since degradation of biodegradable plastic requires certain conditions, especially microorganisms, it will not degrade in daily use and can be used with confidence.

5. As an ordinary consumer, how should I judge whether the biodegradable plastic products I buy meet the national requirements?

First of all, we can see the material identification on the product or product label or outer packaging or instructions of the biodegradable plastic products we buy, such as PLA, PBAT, PBS, PCL, PGA, PHA, PHB, PHBV, PPC, etc., or the co-blends of these materials, such as PBAT+PLA, etc. These material identifications are material identifications of fully degradable materials.

Sources of article:
https://www.youtube.com/watch?v=wf8ByPnm8QI