Is a garbage bag biodegradable? (3 types of garbage bags)

This blog shall answer the question of the biodegradability of garbage bags.

It shall also cover other areas such as:

  • Applications of garbage bags.
  • Materials used to make garbage bags.
  • The biodegradation process.
  • Types of garbage bags.
  • Eco-friendliness of garbage bags.

Is a garbage bag biodegradable?

Yes, the garbage bag is biodegradable when it is made from biodegradable materials such as bioplastics. But it is non-biodegradable when it is made from non-biodegradable materials such as synthetic plastics.

Biodegradation is a natural process that involves microorganisms. The microorganisms have their enzymatic machinery that acts on some materials such as plants and animal parts. 

Let us look at the process of biodegradation for a comprehensive understanding.

What is biodegradation?

Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi into the water, carbon dioxide, methane, and minerals. Heat energy is produced in the process.

Biodegradation occurs in three distinct stages: biodeterioration, bio-fragmentation, and assimilation.

Biodeterioration is the first stage of biodegradation that involves abiotic factors such as light, UV radiation, and water to help in the weakening of the structure of organic substances.

Bio-fragmentation is the second stage that involves the physical breakdown of organic matter into small particles, this is due to the biodeterioration of the organic matter in the first stage.

Assimilation is the last stage of biodegradation. It involves the bacteria and the fungi taking up the minerals and small biomass produced by the previous two stages into their biological systems.

The minerals are used as a source of energy and carbon for the synthesis of cells and tissues.

Biodegradation can occur in the presence or absence of oxygen. When biodegradation involves the microorganisms using oxygen, the process is called aerobic biodegradation.

Aerobic biodegradation produces carbon dioxide, water, and small biomass. Heat energy is also produced in the process. Aerobic biodegradation occurs very fast but it is not very efficient.

When biodegradation occurs in the absence of oxygen, it is called anaerobic biodegradation. The products of anaerobic biodegradation include water, carbon dioxide, and small biomass. In addition to these products, methane gas is also produced. Heat energy is released during the breakdown. 

Anaerobic biodegradation occurs slowly but is more efficient than aerobic biodegradation.

Biodegradation can be affected by several factors such as water, light, temperatures, the bioavailability of a molecule, and pH.

Water helps in the biodeterioration and mechanical fragmentation of substances, increasing the surface area for microbial degradation.

Light emits radiations that help in the biodeterioration and bio-fragmentation of organic matter. UV radiation is the most effective radiation. 

Temperature affects the rate of biodegradation. Some microorganisms are very active in high temperatures while others are active in low temperatures. The optimum temperatures for the microorganisms increase the rate of biodegradation.

Bioavailability is the availability of an organic substance to microorganisms. Highly concentrated organic matter has high bioavailability and this increases the rate of biodegradation.

pH is the measure of acidity or basicity of a substance. Some microorganisms are very active in acidic pH while others are active in neutral or alkaline pH. Optimum pH increases the rate of biodegradation.

What is a garbage bag?

A garbage bag, also called a rubbish bag, bin bag, bin liner, trash bag, or refuse sack is a bag that is used to contain solid waste material.

The bags are disposable and come in different colors such as green, black, or white.

The bags are useful in storing wastes, mostly kitchen wastes, and are wrapped to prevent the spread of waste odor. They are lightweight and are also used to line litter and waste bins.

Some bags contain a thick wire lining at the top which is used to seal the garbage bag once it is filled.

Garbage bags can be incinerated together with the wastes or can be taken to landfills. Some bags are made of biodegradable materials and therefore may be left to break down.

What are the types of garbage bags?

Garbage bags are categorized depending on the material from which they are made.

The different types of garbage bags depending on their material component include:

  • Plastic garbage bags.
  • Bioplastic garbage bag.
  • Oxo-biodegradable garbage bag.

Plastic garbage bags.

These are garbage bags derived from plastic materials. The most common type of plastic used is polyethylene; with low-density polyethylene the most popular plastic used, followed by high-density polyethylene.

Low-density polyethylene.

This is a thermoplastic polymer of ethylene.

It was the first polyethylene plastic to be synthesized.

It still is a very common plastic in industries. It is the most used plastic material to make garbage bags.

Properties of low-density polyethylene.

The following are the properties of low-density polyethylene.

  • It is inert at room temperature.
  • It is affected by strong solvents.
  • It can withstand slightly high temperatures.
  • It is tough.
  • It is flexible.
  • It is less crystalline.
  • It has a low tensile strength.
  • It produces greenhouse gases methane and ethylene.
  • It easily breaks down as compared to other plastics.

High-density polyethylene (HDPE).

High-density polyethylene is a thermoplastic polymer of ethylene.

It is the second most popular plastic material used to make garbage bags.

Properties of high-density polyethylene.

The following are the properties of high-density polyethylene:

  • It is resistant to corrosion.
  • It has a high strength-to-density ratio.
  • It has high tensile strength.
  • It can withstand high temperatures.
  • It is resistant to chemicals.
  • It is inert.
  • It is resistant to microbial degradation.

Bioplastic garbage bags.

Bioplastics are made from plant-based materials. These plastics may be reinforced with synthetic plastics to increase their durability.

The following bioplastics can be used to make garbage bags.

Polyhydroxy-alkanoate plastic.

This is a bioplastic produced in nature by bacteria when they ferment sugar or lipids.

The properties of polyhydroxy-alkanoate are determined by the polymers used to make it.

Properties of polyhydroxy-alkanoate plastic.

The properties of polyhydroxy-alkanoate include the following.

  • It is less elastic than other bioplastics.
  • It is less ductile than other bioplastics.
  • It is biodegradable.
  • It is optically active.
  • It is biocompatible.
  • It is highly porous.
  • It is immunotolerant.
  • It has low toxicity.

Polylactic acid (PLA) plastics.

These are plastics produced from maize starch dextrose.

Properties of PLA plastics.

Its properties include.

  • It is biodegradable.
  • It has low tensile strength.
  • Low thermal resistance.
  • It has high gas permeability

Poly-3-hydroxybutyrate plastics.

This is a bioplastic produced from glucose and maize starch through fermentation by bacteria.

Properties.

The following are its properties.

  • High tensile strength.
  • Resistant to organic solvents.
  • Resistant to heat.
  • It is biodegradation.

Polyamide 11 plastics.

This is a bioplastic derived from natural animal oil.

Properties.

The following are the properties of polyamide 11 plastics.

  • It has a high thermal resistance.
  • It is resistant to water permeability.
  • It has a relatively high tensile strength.
  • It is resistant to abrasions.
  • It is partially biodegradable.

Oxo-biodegradable garbage bags.

These are garbage bags made from plastic materials that have been mixed with some chemicals to make them degradable.

Oxo-biodegradation is the breakdown of materials by oxidation reactions.

Oxo-biodegradable plastics are mixed with chemicals that make the plastics degrade by the oxidation process.

The papers degrade the presence of oxygen and high temperatures. After the oxo-biodegradation, microorganisms in the garbage waste start the process of biodegradation.

So oxo-biodegradation is like an initiation process, the oxidation reactions break down plastics into smaller fragments which are then broken down by microorganisms.

Oxo-biodegradation does not make a material fully biodegradable though, and therefore may take a very long time to fully degrade. 

Is a garbage bag eco-friendly?

Yes, garbage bags are eco-friendly. They help in the disposal of waste products, therefore minimizing the disposal of wastes in the environment.

According to a study, plastic bags can be reused and recycled while bioplastics can degrade, reducing waste in the environment.

However, garbage plastics can be a source of pollution if not used well. The bags are made from plastic materials that are non-biodegradable and therefore may accumulate in the environment.

Oxo-biodegradable plastics may break down into microplastics that accumulate in the water, affecting aquatic life.

Conclusion.

This article has answered the question of the biodegradability of garbage bags.

It has also covered other areas such as:

  • Applications of garbage bags.
  • Types of garbage bags.
  • Eco-friendliness of garbage bags.

For any questions or comments please use the comment section below.

Frequently Asked Questions (FAQs): Is a garbage bag biodegradable?

Can plastic bags be biodegraded?

Synthetic plastic bags such as polythene bags are non-biodegradable. Plastics made from organic materials such as plant products are biodegradable.

Are garbage bags plastic?

Yes, garbage bags are generally made from plastic materials such as low-density polyethylene.

What bags are biodegradable?

Some garbage bags made from plant-based materials are biodegradable. These are bags made from bioplastics derived from cellulose, starch, or lipids 

Citations.

Brody, A. L., and Marsh, K, S., Encyclopedia of Packaging Technology, John Wiley & Sons, 1997, ISBN 0-471-06397-5

Chiellini, E.; Corti, A.; D’Antone, S.; Baciu, R. (1 November 2006). “Oxo-biodegradable carbon backbone polymers – Oxidative degradation of polyethylene under accelerated test conditions”. Polymer Degradation and Stability. 91 (11): 2739–2747. doi:10.1016/j.polymdegradstab.2006.03.022

Brandl H, Püchner P (1992). “Biodegradation Biodegradation of Plastic Bottles Made from ‘Biopol’ in an Aquatic Ecosystem Under In Situ Conditions”. Biodegradation. 2 (4): 237–43. doi:10.1007/BF00114555. 

What was missing from this post which could have made it better?

Leave a Comment