Plastic pollution, safety of biodegradable plastics.

Plastic pollution, safety of biodegradable plastics.

Life of the modern person   is impossible  without products from plastic.   According to the statistics since    the middle of the last century more than 8.3 billion tons of plastic materials have been produced, and only 21% from them are    are recycled , and other 79% get on dump or to the environment. The big problem is made by those products which the person uses daily and which service life is very short . (for example, disposable tableware). This plastic waste does not decompose  and as a result remains on dumps   for many decades .  For the complete decomposition   of plastic bottle under the influence of ultraviolet light and temperature changes , it will take from one hundred to five hundred years.

Ways of utilization and processing of plastic waste:

1.Dumps. It is the cheapest, but unsafe way of waste recycling. Due to the penetration of atmospheric precipitation and storm drains toxic   substances enter the  underground waters.

2. Burning. It is established that  by the burning plastic, polyethylene or products from polyvinylchloride dioxins are released. They are known as  dangerous poisons which act  at the  cellular level and poison organism.

3. Pyrolysis. It consists in the thermal decomposition of substances at   high  temperature. However , this  method  is considered not   very cost-effective, since as a result of pyrolysis, harmful chemical compounds arise and expensive equipment and filters are used to prevent them from entering the atmosphere.            

4. The mechanical recycling is way of processing of waste which is carried out due to crushing of plastic waste, and further their thermal forming.

Currently active developments on plastic replacement with alternative materials which would be quickly utilized   of after use without polluting the environment.Biodegradable plastic gains huge popularity as it is eco-friendly and safe for the environment.

The term biodegradable plastics includes wide range of the polymers that can, under appropriate conditions, decompose into components that are harmless to nature.The great popularity was gained by bio-bags which decompose faster and better than simple polyethylene, and do not pollute the environment. Externally, bio-packages are no different from simple packages. Most biodegradable materials are made from plant-based raw materials. Currently, natural polymers such as cellulose, natural rubber, and others are used. Great interest is attracted by starch as raw materials, rather inexpensive at the price,  which is obtained from potatoes, wheat, corn, rice.

Now produce commercially the following biodegradable plastic: polylactide (PLA) which accounts for 24% of global production of biodegradable polymers, starch mixtures (43.8%), biodegradable polyesters, including polibutilensuktsinat (PBS) and  polibutilenadipattereftalat. (PBAT) (23%) and    polyhydroxyalconates  (PHAs)(5.6%).

Today world production and expense of biodegradable plastics increases high rates.However, special conditions are required for the decomposition of such products. In the natural environment, biodegradable materials decompose only partially, leaving small plastic pieces and pellets. It exacerbates the problem of environmental pollution by microplastics.

The production of biodegradable materials requires a large amount of energy and water, valuable organic cultures,    that leads to production rise in price. Biodegradable packaging materials are 10-15% more expensive than traditional ones.   However consumers, especially in the developed countries, are ready to pay more, getting the products packed into eco-friendly material, taking care of their health and the environment.

In the countries where there is no developed infrastructure for ensuring the correct utilization of biodegradable materials, the introduction of compostable and biodegradable bags can only increase plastic pollution.

 

 jpg