Biodegradable materials are substances that decompose easily through the actions of bacteria, fungi, and other living organisms. Biodegradable substances usually include the substances found in day-to-day usage, for instance, food refuse, tree leaves, and grass clippings. Plant materials are usually biodegradable materials.
Biodegradable materials can be easily handled. Most of the communities encourage other people to compost materials and then further utilize them as an organic-rich material in soil, termed as humus. Therefore, gardening is encouraged. This process is known as composting.
Examples of Biodegradable Materials
- Paper and food waste.
- Human waste.
- Manure.
- Sewage sludge.
- Hospital waste.
- Slaughterhouse waste
- Dead animals and plants.
- Food waste
Biodegradable materials classification
Decomposition
Decomposition is a process that takes place when bacteria and other micro-organisms consume biodegradable materials. The material is dumped into a pit in order to simulate decomposition. Temperature and sunlight play a crucial role in initiating decomposition of the biodegradable substances. Synthetic fibers are chemicals that are not decomposed and are therefore non-biodegradable. These fabrics are ignored by bacterial organisms. Synthetic fibers don’t decompose for about a decade and remain in the environment.
Decomposition is a crucial phenomenon in order to scrape off toxic substances, which may have a hazardous impact on the soil and water. They remain in the environment for a huge number of years. Without decomposition, the non-biodegradable pollutants may harm both the organisms as well as the surroundings.
How are things biodegraded?
The process of biodegradation is initiated mainly by the microorganisms like bacteria and fungi. Microorganisms depend on their enzymes to start the breakdown of substances. This process is carried in the presence of suitable optimum conditions like temperature, moisture, pH of the medium, oxygen level. Biological catalysts such as enzymes can be used to increase the rate of the reaction.
Biodegradable Wastes
Biodegradable waste materials comprise of any organic matter which can be decomposed into various chemicals or simple organic molecules carbon dioxide, water, methane. The decomposition is stimulated by the action of micro-organisms by initiating the processes like composting, aerobic and anaerobic digestion. For instance, sulphates can be decomposed to produce hydrogen sulphide. Inorganic materials can also be decomposed by bacteria during waste treatment. For instance, gypsum and its products. Waste management can also include the reduction of waste production. The domestic waste collection involves the handling in the local waste handling facilities.
Lack of biodegradable waste handling may lead to an adverse effect on climate. For instance, methane emission from anaerobic fermentation may result in the production of landfill gas.
Identifying biodegradable waste
Biodegradable waste is usually comprised of plant, animal, or even of mineral origin. It may be decomposed by the action of microorganisms or animals and then further absorbed.
Harmful effects of Biodegradable Waste
Biodegradable wastes may pollute and impact the environment in the following ways:
- A large amount of microbial flora around the wastes is produced which may increase the risk of communicable diseases in humans, plants, and animals caused by microbes.
- Bad odour on burning may be produced due to the emission of certain gases.
- Waste collection may lead to dungeons of garbage thus promoting the carriers and vectors like mosquitoes and rats to spread communicable diseases.
Here is how long it takes for some commonly used products to biodegrade when they are scattered about as litter:
| Cotton rags | 1-5 months |
| Paper | 2-5 months |
| Rope | 3-14 months |
| Orange peels | 6 months |
| Wool socks | 1 to 5 years |
| Cigarette butts | 1 to 12 years |
| Plastic coated paper milk cartoons | 5 years |
| Leather shoes | 25 to 40 years |
| Nylon fabric | 30 to 40 years |
| Plastic 6-pack holder rings | 450 years |
| Glass bottle | 1 million years |
| Plastic bottles | Forever |
Non-biodegradable Materials
Non-biodegradable substances cannot be broken down by natural organisms, therefore may act as a source of pollution. These types of wastes cannot be easily handled. It cannot be broken down by the naturally occurring agents, and continue existing on the surface of the earth for a large number of years. Most of the inorganic substances are non-biodegradable. “Recyclable waste” is the waste materials that can be recycled.
The non-biodegradable wastes are not environment friendly, therefore, they pose a serious threat to the environment and surroundings. They pose a real threat to space. For instance, plastic is used in all fields in day-to-day lives. They are not decomposed by the microbes, therefore, an alternative is needed to replace these. Improved quality plastics can be used which are more durable and resistant to temperature. Biodegradable plastics can be used as a substitute that has a rapid degeneration process. However, the manufacturing process is expensive.
Another daily case is visible in the case of the household detergents. The foam in the detergents is caused by a chemical complex phosphate, sodium tripolyphosphate, which removes dirt from the surfaces of clothes. These complex phosphates are termed surfactants and are not biodegradable. Detergent manufacturers have started replacing phosphates with biodegradable enzymes like protease and amylase.
| Basis for comparison | Biodegradable Materials | Non-Biodegradable Materials |
| Definition | The wastes that decomposes naturally in the environment. | The wastes that do not decompose naturally in the environment and cause pollution. |
| Examples | Dead plants and animals. | Plastic, rubber, plastic, metals, etc. |
| Rate of fertilizersdecomposition | High. | Low |
| Decomposed by | Bacteria, fungi, and other living organisms | Not decomposed easily by the action of naturally occurring agents. |
| Use | Can be used to produce biogas, manure, fertilizers, compost, and other substances after decomposition. | Degradation rate is slow and the separation and recycling is difficult and expensive too. |
Examples of Non-biodegradable Materials
- Glass
- Plastic
- Metals
- Hazardous substances
- Pesticides
- Fibers
- Glass
- E-waste
- Artificial rubber
- Artificial polymers
Harmful effects of non-biodegradable waste
Biodegradable waste materials emit out organic pollutants both in water as well as surroundings. The non-biodegradable substances are not dismantled and therefore, remain in the environment. Their accumulation releases harmful gases, for instance, electronic waste materials release volatile gases and greenhouse gases like carbon dioxide, methane, and carbon monoxide. This also causes hazardous environmental issues, for example, depletion of the ozone layer as well as acid rains.
The accumulation of non-biodegradable substances have the following harmful effects:
- They modify the properties of the medium. In the case of landfills the properties of the soil change with respect to its pH value and fertility.
- It causes an adverse impact on the flora and fauna.
- Leaching – Toxic substances in the water dissolve in the soil profile and then are mixed with the groundwater. This causes adverse effects on life (plants and animals as well as humans) as well pollutes the groundwater.
- It affects the water quality in the terms of aquatic life and water microflora as well as affects the water index. Therefore, the water becomes unfit for both consumption and neither is portable.
Treatments
Treatment of wastes is important to reduce the adverse impact of waste materials on both animal and plant life. In addition to the norms set by the government, individuals should also make efforts to treat wastes. The three Rs– Recycle, Reuse, and Reduce should be followed to prevent the accumulation of waste. This will also result in better utilization of energy and other resources as well. Also, an attempt should be made to dispose of both the type of materials in different categories.
Sample Questions
Question 1. Will the generation of only biodegradable wastes have any impact on the environment?
Answer:
If all the waste we generate is biodegradable, this would also have an impact on the environment, but most of the impacts would be positive. After decomposition, the biodegradable substance produces different raw materials which are sent back to the ecosystem. The solid remains would add to the humus content of the soil.
There can be some negative impacts; like obnoxious smell which is created during the process of decomposition. There can also be a possibility of sparking an epidemic if the waste is dumped near a residential area or is allowed to contaminate the water bodies. So, it is not the biodegradable waste that is going to create the problem, rather the way we dispose it of.
Question 2. Why are synthetic fibers considered to be non-biodegradable?
Answer:
Synthetic fibers are man-made fibers produced artificially. For instance, plastic and other synthetic fabrics like rayon, nylon or acrylic are not mixed into the soil and therefore, pose serious implications.
Question 3. Differentiate between the biodegradable and non-biodegradable materials.
Answer:
| Biodegradable Waste | Non-biodegradable Waste |
| Can be decomposed into simple, non-poisonous substances by the action of micro-organisms in nature. | Cannot be decomposed into simple, non-poisonous substances by the action of micro-organisms in nature. |
| They can be recycled naturally as well as by man and their products do not pollute the environment. | They cannot be recycled naturally as well as by man and their products cause environmental pollution. |
| Composed of natural ingredients. | Composed of synthetic materials. |
| They can produce useful products after biodegradation. | They remain unchanged chemically as they are non-biodegradable. |
| No effect on ecological balance in nature. | Disrupt the ecological balance in nature. |
| Remain for small-time intervals in the environment. | Remain for longer time intervals in the environment. |
| Examples: Paper, cow dung, etc | Examples: Plastic bags, synthetic fibers, cans, etc |
Question 4. Do biodegradable substances affect the environment and how?
Answer:
Biodegradable materials are decomposed down by the microorganisms, for instance, bacteria and fungi. They degrade down into simpler soluble substances and are therefore, used as a source of nutrients by these organisms. Some of these materials mix well into the soil thereby increasing its fertility.
Question 5. Why should we segregate biodegradable and non-biodegradable wastes?
Answer:
Biodegradable and non-biodegradable wastes should be discarded in different bins to ensure:
- Separate collection and dealing
- Effective treatment and disposal.
- Prevent the formation of toxic compounds on their mixing
- Prevent emission and pollution in the environment.
The biodegradable waste, for example, can be decomposed naturally, that is, by the process of composting. Non-biodegradable wastes, however, can be sent for recycling.
Question 6. How to minimize plastic-related Environmental problems?
Answer:
Plastic is now an integral part of our life. Plastic industry is growing with a lot many Environmental problems. We have various options and technologies, but each one has its own merits and demerits.
- Is it possible to ban plastic? The answer may be a big No.
- We may ban a particular type of plastic? If yes, what type of plastic could be banned?
- Reduce it use? But the problem will be there again.
- Recycling is one good option but not cost-effective.
