Composting is an eco-friendly and rewarding way to recycle organic waste, reducing landfill contributions while creating nutrient-rich soil. Choosing the right compost bin is crucial for optimizing the composting process. Here’s a comprehensive comparison of various compost bin types, their pros and cons, and essential factors to consider before making a purchase.
There is no one best compost bin because we all have different requirements. Instead I will present here the different types of compost bins so you can decide which fits your needs.
Digesters
A digester, in the context of biology or waste management, is a container or system that facilitates the process of biological digestion. It is designed to break down organic materials, such as food waste, sewage, or agricultural byproducts, in an oxygen-free (anaerobic) environment.
The basic principle behind a digester is the utilization of microorganisms to break down complex organic matter into simpler compounds, such as methane, carbon dioxide, and solids. These microorganisms, called anaerobic bacteria or archaea, thrive in an oxygen-depleted environment and carry out the process of anaerobic digestion.
How Digesters Work
- Collection: organic waste material, such as food scraps, agricultural residue, or sewage, is collected and fed into the digester.
- Anaerobic environment: The digester is sealed to prevent the entry of oxygen, providing an ideal environment for anaerobic bacteria to thrive.
- Microbial activity: the microorganisms present in the digester start breaking down the organic matter through a series of biochemical reactions. Complex organic compounds are converted into simpler forms by these bacteria.
- Acidogenesis: during this stage, fermentative bacteria convert the organic matter into volatile fatty acids, alcohols, and other intermediate compounds.
- Acetogenesis: in this phase, acetogenic bacteria convert the volatile fatty acids produced in the previous step into acetate and hydrogen.
- Methanogenesis: methanogenic bacteria consume the acetate and hydrogen, producing biogas rich in methane and carbon dioxide. This biogas can be used as a renewable energy source.
- Residual processing: after the digestion process, the remaining material (digestate) may undergo further treatment for solids separation or composting. The resulting byproducts, called digestate, can be used as nutrient-rich fertilizer.
Pros
- Efficiency. Digesters break down waste quickly due to high internal temperatures.
- Compact. They’re often smaller in size and suitable for smaller yards or urban settings.
- Aesthetics: Some models are designed to blend with outdoor decor.
Cons
- Limited capacity. Smaller size may limit the amount of waste that can be processed.
- Dependency on conditions. They might require specific environmental conditions to maintain optimal functionality.
Fermenters
A fermenter composting system, also known as anaerobic fermentation or bokashi composting, is a method of composting organic waste through the action of microbes in the absence of oxygen. It involves the use of a special container or fermenter that creates anaerobic conditions for the waste to break down.
The resulting compost from the fermenter composting system is typically dark, rich in microbial activity, and retains more nutrients compared to traditional aerobic composting methods. This makes it an excellent fertilizer for gardens and plants.
Additionally, the anaerobic fermentation process can handle a wide range of organic waste, including meat, dairy products, and other materials that may not be suitable for traditional composting methods.
How Fermenters Work
- Collection of organic waste: Food scraps, vegetable trimmings, coffee grounds, paper waste, and other organic materials are collected in a container specifically designed for fermenting compost.
- Inoculating with microbial starter: A microbial starter known as bokashi is added to the organic waste. This starter typically contains Effective Microorganisms (EM), which are a mix of beneficial bacteria, yeast, and fungi. These microorganisms help accelerate the fermentation process by breaking down the waste into simpler compounds.
- Layering: The waste is layered in the fermenter, usually in incremental amounts. Each layer is sprinkled with the bokashi microbial starter to ensure even distribution of the beneficial microorganisms.
- Sealing the container: The fermenter is tightly sealed to create an anaerobic environment, preventing the entry of oxygen. This favors the growth of anaerobic microorganisms that will ferment the waste.
- Fermentation process: Over a period of several weeks, the waste undergoes fermentation. The anaerobic microorganisms break down the organic matter, converting it into simpler compounds, such as organic acids, alcohols, and gases like methane. This process occurs without the production of foul odors, thanks to the use of the bokashi starter.
- Maturation period: After the fermentation process is complete, the fermented waste is generally removed from the fermenter and undergoes a maturation period. During this time, the compost is typically buried in soil or added to a regular compost pile, where it further decomposes and matures into nutrient-rich compost.
Pros
- Speed. Fermenters accelerate decomposition due to anaerobic breakdown.
- Minimal odor. Properly managed, they produce minimal smell.
- Space-saving. Compact and suitable for smaller spaces.
Cons
- Anaerobic conditions. Lack of oxygen might slow down the breakdown of certain materials.
- Maintenance. Requires regular monitoring and maintenance to avoid unpleasant odors.
Compost Tumblers
A compost tumbler is a container designed for the efficient decomposition of organic waste, such as kitchen scraps and yard waste, into nutrient-rich compost. It is a cylindrical or drum-shaped container that can be rotated or turned easily to facilitate the composting process.
How Compost Tumblers Work
Compost tumblers work by providing an environment where organic matter can decompose quickly and efficiently through the process of aerobic decomposition. When organic waste is added to the tumbler, it is mixed and aerated by rotating the container.
This allows oxygen to circulate throughout the composting materials, promoting the growth of aerobic microorganisms that break down the organic matter.
The rotation of the tumbler helps distribute moisture and oxygen evenly, preventing the waste from becoming compacted or waterlogged. It also helps speed up the decomposition process, as the constant mixing exposes more surface area of the organic materials to the microorganisms responsible for breaking them down.
As the organic waste decomposes, heat is generated within the tumbler. This helps accelerate the breakdown of the materials and aids in killing any weed seeds or pathogens that may be present. The end result is rich, dark compost that can be used to nourish plants and improve soil health in gardens and landscapes.
Related. Everything You Need to Know about Compost Bins
Pros
- Aeration. Tumbling action enhances aeration, accelerating decomposition.
- Convenience. Easy to turn, reducing the need for manual mixing.
- Rodent control. Elevated design minimizes access for pests.
Cons
- Limited capacity. Smaller models may not handle larger volumes of waste.
- Cost. Some tumblers can be relatively expensive compared to other options.
Worm Bins (Vermicomposting)
A worm bin, also known as a vermicomposting bin, is a container used to house and cultivate worms for composting organic wastes. It provides an ideal environment for worms to break down organic materials, such as food scraps and yard waste, into nutrient-rich compost called worm castings or vermicompost.
How Worm Bins Work
A worm bin can be made from various materials like plastic, wood, or even stacked trays. The bin should have drainage holes at the bottom to prevent excess moisture buildup.
- Bedding: The base of the worm bin is filled with bedding material like shredded newspaper, cardboard, straw, or coconut coir. This bedding provides the worms a habitat and helps maintain moisture levels.
- Worms: Redworms, specifically Eisenia fetida or red wigglers, are commonly used in worm bins. These worms consume organic material and break it down.
Pros
- Efficiency: Worms break down waste rapidly.
- Indoor use. Suitable for indoor use, even in apartments.
- Rich compost. Produces high-quality compost known as worm castings.
Cons
- Temperature sensitivity: Worms require specific temperature ranges for optimal activity.
- Maintenance: Regular care is needed to manage moisture and avoid odor.
Insulated Compost Bins
An insulated compost bin is a container specifically designed to allow for the controlled decomposition of organic materials while maintaining a stable temperature. It is constructed with insulation materials, such as thick walls or double layers, to provide thermal protection and regulate the internal temperature.
This insulation helps in speeding up the decomposition process by creating an ideal environment for the microorganisms responsible for breaking down the organic matter into nutrient-rich compost. Additionally, insulated compost bins can help to retain heat during colder months, ensuring the composting process continues even in low temperatures.
Pros
- Temperature regulation. Maintain optimal temperatures for decomposition.
- Year-round composting. Suitable for colder climates.
- Faster breakdown. Accelerates the composting process.
Cons
- Cost. Insulated bins are often pricier than standard models.
- Limited availability. Might be harder to find compared to other types.
Factors to Consider When Buying a Compost Bin
- Space: choose a bin size that fits your available space and composting needs.
- Ventilation: ensure adequate airflow for proper decomposition.
- Material: consider durability, weather resistance, and aesthetics.
- Maintenance: assess your willingness to regularly maintain and monitor the compost bin.
- Cost: balance your budget with the features and efficiency of the bin.
- Goals: consider the type of waste you’ll be composting and how quickly you want the compost.
Conclusion
In conclusion, the ideal compost bin varies based on individual preferences, space availability, and composting goals. Each type has its own set of advantages and disadvantages, so it’s essential to weigh these factors before making a purchase.
