Organic decay is the process of organic matter breaking down over time. It is a natural process that occurs in nature and is essential for the cycle of life. Organic decay is the result of bacteria, fungi, and other microorganisms breaking down organic material into simpler compounds. This process is also known as decomposition.
Anaerobic decay is a type of organic decay that occurs in the absence of oxygen. This type of decay is usually caused by the presence of microorganisms that produce enzymes capable of breaking down organic matter without the need for oxygen. This type of decay is most commonly found in wet, low-oxygen environments such as lakes, rivers, and wetlands.
Anaerobic decay is a process that takes place in soils and ecosystems that starts with the breakdown of organic material by microorganisms and fungi.
This process results in the release of harmful gases, like hydrogen sulfide, that can kill plants. Anaerobic decay is a major cause of soil erosion and the loss of biodiversity.
Anaerobic Decay
Anaerobic decay is a process that occurs when bacteria and fungi break down dead matter without oxygen. This can happen naturally in soils, marshes and lakes.
Anaerobic digestion facilities generate renewable energy that helps reduce reliance on fossil fuels and greenhouse gas emissions. Additionally, byproducts can be applied to the soil as nutrient-rich fertilizer.
Aerobic Decay
Anaerobic decay occurs when organic compounds break down by living organisms that do not require oxygen. The resulting substances include methane (CH4), organic acids and hydrogen sulfide, many of which have disagreeable odors. The decomposition is accompanied by the release of small amounts of carbon dioxide (C02).
Aerobic decay also releases heat. The amount of heat released depends on the amount of oxygen present and how well it is able to penetrate the material. The less oxygen there is the longer the process will take and the less heat will be generated.
Aerobic decay can occur in pits, bins, stacks or piles if adequate oxygen is provided. It is important to add oxygen regularly by turning the compost at intervals or by other techniques.
What Causes Anaerobic Decay to Occur
The term anaerobic decay refers to the process by which organic material breaks down without the help of oxygen.
Anaerobic decay typically occurs in the complete absence of oxygen, in which anaerobic bacteria convert organic material into gases and resulting heat.
This process can lead to the emission of harmful gases when it occurs unintentionally and without control, including carbon dioxide and methane, which can contribute to climate change.
How can anaerobic decay be used to produce fuel?
Anaerobic decay can be used to produce fuel in the form of biogas. Under control in an anaerobic digestion plant the production of biogas is a very useful form of renewable energy. Odours are minimal when the process is run properly.
Biogas is a mixture of methane, carbon dioxide, and other gases. This biogas can be harvested from anaerobic decay tanks (biogas digesters) and then used to generate electricity.
Anaerobic decay of organic matter can produce useful energy sources such as methane and bio-oil. It occurs when organic material does not receive enough oxygen to break down and produce energy.
In anaerobic conditions, the microbes use up the available oxygen and produce methane and other gases.
A useful end product of controlled anaerobic decay in waste materials as long as the methane produced is 100% collected and used
The byproducts of anaerobic decay in waste organic materials can be used to create products that are environmentally friendly and useful. One such product is methane gas, which can be used for energy production or as a propellant in gas tanks.
A useful end product of anaerobic decay is compost. Compost is a natural fertilizer that is produced through anaerobic decay. Compost is rich in nutrients and can be used to fertilize gardens, farms, and other agricultural areas.
Why is anaerobic decay bad for compost?
Anaerobic decay is bad for compost because it produces harmful greenhouse gases and a bad odour.
Anaerobic decay of organic matter produces methane, carbon dioxide, and water vapour. Methane is the most harmful gas because it is over 35 times more potent than carbon dioxide over a 100-year period.
When anaerobic decay occurs, it produces odours and toxic chemicals that can be harmful to plants and animals. The presence of these odours and chemicals can prevent the composting process from being effective.
Putrefactive Anaerobic Decay
Anaerobic decay is the breakdown of organic compounds without oxygen. It occurs when organisms that can live without air, such as yeasts and bacteria, break down the compounds to organic acids and methane (CH4).
These organisms also release large amounts of energy, primarily in the form of heat. This is a great advantage over aerobic decomposition, which uses oxygen to produce energy.
The process of putrefactive decay can speed up or slow down based on the factors listed below:
Environmental temperature and moisture. Temperatures between 21 degrees C and 38 degrees C promote the chemical breakdown of tissue, while high humidity levels aid in growth of microorganisms.
Bodies within deep graves tend to decompose more slowly than bodies in shallow graves. This is because burial can help retain body temperature and moisture, slowing the bacterial breakdown of tissues.
Some pathogenic bacteria are capable of utilizing a variety of putrefaction pathways, which lead to the production of certain metabolites like ammonia, cadaverine, cresol, indole, phenol and H2S. These pathways are facilitated by genes that encode for the putrefactive enzymes and other cellular components involved in the process.
Anaerobic decay in compost piles can lead to numerous problems, including foul odors, reduced decomposition rates, and the production of harmful compounds. This article explores the scientific principles behind preventing anaerobic conditions and maintaining optimal aerobic decomposition in composting systems.
Understanding Anaerobic vs. Aerobic Decomposition
Composting is fundamentally a biological process where microorganisms break down organic matter. While both aerobic and anaerobic decomposition can occur naturally, aerobic decomposition is generally preferred for composting due to its faster rate, higher temperatures, and more complete breakdown of organic materials.
Aerobic decomposition requires:
- Oxygen levels above 5% throughout the pile
- Proper moisture content (40-60%)
- Appropriate carbon-to-nitrogen ratio (25:1 to 30:1)
- Adequate porosity for air movement
Key Strategies for Preventing Anaerobic Conditions
1. Optimal Particle Size Distribution
Maintaining proper particle size distribution is crucial for creating adequate pore space within the compost pile. Research indicates that a mix of particle sizes between 1/2 inch to 2 inches (1.3-5.1 cm) provides optimal air space while maintaining sufficient surface area for microbial activity.
2. Moisture Management
Water content must be carefully controlled to prevent anaerobic conditions:
- Maintain moisture levels between 40-60%
- Use the squeeze test: material should feel like a wrung-out sponge
- Monitor rainfall and cover piles during heavy precipitation
- Ensure adequate drainage at the base of the pile
3. Proper Aeration Techniques
Regular aeration is essential for maintaining oxygen levels:
- Turn piles every 3-7 days during active composting
- Use perforated pipes or aeration systems for passive airflow
- Monitor internal temperature as an indicator of aerobic activity
- Maintain pile height between 4-6 feet (1.2-1.8 m) to prevent compression
4. Structural Amendments
Adding bulking agents can improve air circulation:
- Wood chips (recommended size: 1-2 inches)
- Straw or hay (chopped to 4-6 inches)
- Corn stalks or similar rigid materials
- Maintain 30-35% bulking agent by volume
Monitoring and Troubleshooting
Key Indicators of Anaerobic Conditions:
- Odor characteristics:
- Rotten egg smell (hydrogen sulfide)
- Putrid or sour odors
- Ammonia-like smells
- Physical characteristics:
- Wet, matted materials
- Dark, slimy texture
- Cold or cool internal temperatures
Corrective Actions
When anaerobic conditions are detected:
- Immediately turn the pile to incorporate oxygen
- Add dry, carbon-rich bulking materials
- Reduce pile size if compression is evident
- Install additional aeration mechanisms if needed
Preventing anaerobic decay during aerobic composting requires careful attention to pile construction, monitoring, and maintenance. By maintaining proper moisture levels, particle size distribution, and aeration, composters can ensure efficient aerobic decomposition and produce high-quality compost.
Microorganisms
Microorganisms are a group of tiny living organisms that can be bacteria, archaea, fungi, protozoa, algae, and viruses. These microscopic organisms are essential for life on Earth.
Fungi, for example, are microorganisms that make dead things decay and rot. They include mushrooms and moulds, as well as yeasts that make bread.
Algae are microscopic organisms that produce energy through photosynthesis, similar to plants. They are very important for pumping oxygen into the atmosphere, but they can also cause harm.
In contrast, bacteria do not require oxygen to live. They use a complex system of molecules to turn organic waste into nutrients.
Bacteria are an essential part of the composting process, contributing to the breakdown of organic matter and decomposing it into a range of different products. The rate of decomposition is determined by the temperature, moisture and chemical composition of the organic material.
Physical Decomposers
Besides bacteria and fungi, there are other organisms that break down organic matter into smaller parts. These are called decomposers. These include earthworms, which live in the soil and break down waste into organic material.
These decomposers can also help to keep nutrients in the environment. They recycle dead plants and animals into chemical nutrients such as carbon and nitrogen that are released back into the soil, air and water as food for living plants and animals.
They can also play a role in bioremediation, which is the use of natural living things to clean up polluted soil or water in a more environmentally friendly way. For example, engineers can use earthworms to break down toxic oil spills in the ocean or sewage in a city into harmless byproducts that do not harm the environment or humans.
However, not all decomposers are beneficial to the environment. Some microbes are not able to thrive under certain conditions, such as too much light or too much moisture.
Conclusion
In conclusion, anaerobic decay is an essential part of the cycle of life and can be used to produce fuel and beneficial compost. However, it can also produce odours and toxins that can be harmful to the environment. It is important to be aware of the potential risks associated with anaerobic decay and to take proper precautions when dealing with it.
Bacteria, fungi, and other microorganisms break down organic material into simpler compounds.
