The world wastes about 1.3 billion tons of food every year. That's one-third of all food produced globally.
Where does this food waste go? In the landfills, where it decomposes without oxygen and produces methane, a potent greenhouse gas.
Not only does food waste contribute to climate change, but it also wastes valuable resources such as water and land. Therefore, businesses need to opt for sustainable food waste solutions that lower their environmental impact while also reducing costs.
The two primary food waste solutions businesses can choose from are composting and anaerobic digestion. While the former involves decomposing food waste to create organic fertilizer, the latter produces biogas. Let's learn more about both of them.
Overview of Anaerobic Digesters and Aerobic Composters
Both anaerobic digesters and aerobic composters are food waste solutions that have their own benefits and drawbacks. Let's discuss.
Anaerobic Digesters
Anaerobic digestion occurs in the absence of oxygen. That means microorganisms digest organic waste to produce biogas and digestate, a nutrient-rich fertilizer.
The basic principle of anaerobic digesters is simple. The equipment consists of tanks or vessels where microorganisms break down organic waste through a series of biochemical reactions.
There are three main types of anaerobic digestion systems:
- Passive systems: Incorporate biogas recovery into an existing treatment component.
- Low-rate systems: Primarily use manure flowing through the digester as the main source of methane-forming microorganisms.
- High-rate systems: Trap methane-forming microbes inside the digester to improve efficiency.
The benefits of anaerobic digestion include production of renewable energy, reduction in greenhouse emissions, production of nutrient-rich fertilizer, and reduction in odors and pathogens.
However, the primary drawback is that it requires a significant amount of initial investment and expertise to operate. However, it results in a better ROI due to income from energy.
Ideal Use Cases
Anaerobic digestion can be an ideal solution for Commercial kitchen food waste management, such as in industrial or municipal settings. It also benefits agricultural operations since it's the source of hospitals, school cafeterias, or supermarkets, including:
- Nutrient-rich fertilizer
- Animal bedding
- Organic-rich compost
- Soil amendments
Aerobic Composters
Aerobic composters use oxygen-dependent microorganisms to decompose organic waste. An abundant amount of oxygen is needed to carry out aerobic digestion. The end products are carbon dioxide, ammonia, heat, and water.
The sizes of aerobic composters differ based on their models. For example, the Elite II in-vessel composter from EcoRich uses heat, a heat-tolerant microbe, and fresh air to break down pathogens and food waste.
It takes 24 hours to reduce the volume of food waste by 90%. Plus, it only needs to be emptied every 3 to 7 days.
The composter comes in different models, ranging from a daily waste processing capacity of 20 pounds to 4,000 pounds. Businesses can select a model based on their waste production.
Some notable benefits of aerobic digestion for sustainable waste management include:
- Efficient breakdown of organic waste
- Reduced production of toxic gasses and odors
- Quick processing time, which leads to reduction in storage space
- Nutrient-rich compost as a by-product
- Kitchen staff friendly
However, it also has a few shortcomings, such as:
- Higher energy consumption for aeration and maintenance
- Initial high cost of installation
- Need for regular monitoring of the compost pile
- Higher energy cost compared to rotary composter
- Final quality of soil amendment depends on what goes in.
Ideal Use Cases
Aerobic composters are an ideal waste management solution for a wide range of businesses, such as restaurants, grocery stores, schools, hospitals, and residential communities. It's also a great option for municipalities and waste management companies.
Comparative Analysis
Let's look at both aerobic and anaerobic digestion in a side-by-side comparison to understand their differences.
Environmental Impact
Both types of digestion can significantly reduce the amount of waste sent to landfills. They also reduce a business's carbon footprint.
However, aerobic composting can have several negative environmental impacts. First, it consumes a lot of water and energy for operating. It also produces volatile organic compounds (VOCs) and foul odors.
The gasses produced during composting can contribute to photochemical oxidation and acidification of the local ecosystem. They may also result in eutrophication, which is the excessive algal growth in lakes and rivers due to the high levels of nutrients in them.
Similarly, if mishandled, the digestate produced during anaerobic digestion can result in eutrophication and hypoxia (low oxygen levels) in water bodies. However, this can be prevented with proper management strategies.
Economic Considerations
Anaerobic digestion plants need a high upfront investment, but operational costs are low and there is continuous income from energy.
On the other hand, aerobic composting is less expensive to set up. However, finding use of compost is challenging.
The financial benefits of both types of digestion vary depending on factors such as the scale of operation and feedstock availability. However, by producing valuable biogas and fertilizer, anaerobic digestion plants can generate income for a business.
Operational Factors
Aerobic composting, although more rapid, needs larger space. Since composters need ample air space for air wells, they have a larger footprint compared to anaerobic digesters.
As for maintenance, aerobic composting may need more attention as it's highly dependent on proper moisture and oxygen levels.
Aerobic composters are faster than their anaerobic counterparts, resulting in a shorter processing time.
For Anaerobic digester energy use needed to be constant. The tank can only hold a certain amount of biogas.
Regulatory and Compliance Issues
The regulations for sustainable waste management differ across states and countries. You must comply with environmental standards in your jurisdiction.
For instance, the Minnesota Pollution Control Agency administers the state regulatory requirements for anaerobic digesters. You can find similar information for other states on the Environmental Protection Agency's website.
Similarly, The Official Information Portal on Anaerobic Digestion provides regulations for all anaerobic digesters in the country. The same applies to all other countries.
Choosing the Right Solution for Your Business
Take the following steps to choose the right sustainable waste management solution for your business.
Business Needs Assessment
First, you must assess the type of food waste your business produces and how much. Plus, determine your space availability and budget availability.
If you primarily produce plant-based food waste, aerobic composting will be more advantageous. It's also a good solution for businesses that cannot afford to spend a large amount upfront.
On the contrary, if you want low operational costs, opt for anaerobic digestion.
Implementation Steps
Once you've selected a system, you should:
- Plan: Comience por crear un plan para su sistema de gestión sostenible de residuos. Incluya el tipo de sistema, el costo, el cronograma y las expectativas de producción. Además, obtenga los permisos y aprobaciones necesarios.
- Instale y entrene: Instale el sistema y capacite a su personal para que lo opere.
- Supervise y optimice: Supervise el sistema y realice mejoras. Optimícelo para lograr la máxima eficiencia.
Conclusión
Como se mencionó, algunos factores importantes a tener en cuenta al elegir una solución de gestión de residuos sostenible para su empresa incluyen el impacto ambiental, las consideraciones económicas, el cumplimiento normativo y la eficiencia operativa.
Un compostador o digestor in situ puede ayudarlo a cumplir sus objetivos de sostenibilidad y ahorrar en los costos de eliminación de residuos. Comience hoy mismo su camino hacia un negocio ecológico contactar con EcoRich para soluciones de compostaje y digestión.
