As global waste generation surges, managing this waste sustainably has become a critical issue. Two widely used methods for waste disposal are landfilling and incineration. Each approach has its advantages and disadvantages, impacting the environment, public health, and economic sustainability in different ways. This article explores these two methods, comparing them in terms of environmental impact, cost, energy production, and overall effectiveness in waste management.
For example: As of the 2020–2021 period, Australia generated approximately 75.8 million tonnes of waste, equivalent to nearly 2.95 tonnes per person annually. Waste production has been steadily rising, with a 20% increase over the past 15 years, driven by the construction and demolition sectors, which contribute 25.1 million tonnes annually. National targets aim to reduce waste generation, but projections suggest growth in waste volume as urban populations expand. By 2030, Australia is targeting an 80% recovery rate to mitigate this growth by enhancing recycling and reuse efforts.
What is a Landfill?
A landfill is a designated area where waste is buried and covered with soil or other materials to contain it. In a sanitary landfill, waste is compacted, layered, and monitored to reduce the risk of contamination to surrounding land and water. The goal is to manage waste in a controlled environment, minimising immediate environmental harm. However, despite precautions, landfills have several inherent downsides.
Environmental Concerns: Landfills emit methane, a potent greenhouse gas (GHG) contributing to climate change. Methane is generated when organic waste decomposes anaerobically (without oxygen), which is unavoidable in landfills. Although some facilities capture methane for energy, not all landfills have this capability, resulting in significant emissions.
Groundwater Contamination: Landfills also pose a risk to local water sources. Leachate, a toxic liquid formed when rainwater filters through waste, can seep into the ground and contaminate nearby water sources. Even modern landfills with protective liners and leachate collection systems cannot guarantee complete safety from potential leaks over time.
Land Use: Landfills require large areas of land, which are often located near urban or suburban regions due to logistical needs, causing disputes over land use. As waste accumulates, these spaces eventually reach capacity and necessitate new locations, encroaching on natural habitats or farmland.
Aesthetic and Health Concerns: Odour and pest problems can make landfills unpopular among residents in nearby areas, creating a "not in my backyard" (NIMBY) response from communities. Studies have also linked living near landfills with certain health risks, though long-term effects remain an area of study.
Incineration: Burning Waste for Energy
Incineration involves burning waste at high temperatures to reduce its volume significantly and, in many cases, generating energy from the heat produced. Waste-to-energy (WTE) incineration plants capture heat and convert it into electricity, offering a renewable energy source while managing waste.
Volume Reduction: Incineration can reduce the volume of waste by up to 90%, drastically reducing the need for land compared to landfills. This is particularly beneficial in densely populated areas where land is scarce, allowing waste management without the constant need for new landfill sites.
Energy Production: Modern incineration plants generate energy by capturing the heat produced during waste combustion. This energy is then used to produce electricity or heat for district heating. According to the International Energy Agency, waste-to-energy plants provided around 2% of global electricity in 2019, though there’s potential for expansion with advances in cleaner incineration technologies.
Environmental Concerns: Incineration emits carbon dioxide and other pollutants, raising concerns about air quality. The process also generates toxic ash, which needs careful disposal. While new technologies have significantly reduced pollutant emissions through scrubbers and filters, critics argue that incineration still contributes to air pollution and GHG emissions.
Resource Loss: Burning waste destroys valuable resources, which could otherwise be recycled or composted. This loss of resources conflicts with the concept of a circular economy, where materials are reused, recycled, or composted rather than discarded.
Comparing Costs
Landfills: The costs associated with landfills include construction, maintenance, leachate management, and methane control. Initially, landfills may seem cost-effective due to relatively low operating expenses, but hidden costs - such as land acquisition, monitoring, and environmental remediation - accumulate over time. These costs increase as landfill sites reach capacity and new locations must be identified.
Incineration: Incineration facilities are capital-intensive, requiring significant upfront investment for construction and ongoing operational costs for maintenance and pollution control. However, the ability to generate electricity can help offset costs, especially in locations with high energy demand. WTE (Waste To Energy) facilities that produce both electricity and district heating can see faster returns on investment.
A lifecycle analysis comparing landfills and incineration reveals significant differences in carbon footprint:
Incineration generally has a lower carbon footprint, emitting -0.179 tonnes of CO2 equivalent per tonne of municipal solid waste (MSW) processed. This is primarily due to energy recovery from waste combustion offsetting fossil fuel use.
In contrast, landfills have a higher carbon footprint of 0.395 tonnes CO2 equivalent per tonne of MSW. This is largely attributed to methane emissions from decomposing organic waste, which is a potent greenhouse gas.
However, the carbon impact depends on factors like waste composition, energy recovery efficiency, and landfill gas capture rates. As grid electricity decarbonizes, incineration's relative benefits may decrease over time
Environmental Impact and Public Health
Both landfills and incineration impact the environment, but in different ways. Landfills contribute to Greenhouse Gas (GHG) emissions and carry risks of water contamination, while incineration releases pollutants that affect air quality.
GHG Emissions: Landfills are a major source of methane, a GHG more potent than carbon dioxide but with a shorter atmospheric lifespan. Incineration mainly emits carbon dioxide. Although incineration produces fewer GHGs overall, it still has a substantial carbon footprint. While some argue that incineration’s GHG emissions are lower than those of an equivalent landfill, both methods fall short in minimising total environmental impact.
Health Risks: Living near landfills has been associated with respiratory issues, low birth weights, and even some cancers, though evidence varies. Incineration, on the other hand, raises health concerns related to air pollution from toxic dioxins and heavy metals, although modern facilities use advanced filtration to minimise these emissions. Nevertheless, communities near incineration plants often oppose them due to perceived health risks.
Waste Hierarchy and the Shift to a Circular Economy
In the context of sustainable waste management, the waste hierarchy prioritises reduction, reuse, and recycling over disposal methods like landfilling and incineration. Both landfills and incineration represent the lower end of this hierarchy, often seen as last-resort options for waste that cannot be reused, recycled, or composted.
Landfills and incineration alike underscore the need to adopt a circular economy approach, where waste is minimised through better design, recycling, and resource recovery. In this model, products and packaging are designed to be reused or composted, reducing reliance on disposal methods. Many countries are adopting policies that encourage recycling, composting, and waste diversion to reduce the volume of waste that reaches both landfills and incinerators.
Which Option is Preferable?
The best waste management approach depends on a region’s specific needs and constraints. In urban areas with limited space, incineration may provide a better solution by reducing waste volume and generating energy. However, in regions where land is abundant, and waste volumes are manageable, landfills may be a more economical option.
Neither method is without drawbacks, and the ideal solution often involves a combination of the two. For example, non-recyclable, high-caloric-value waste can be incinerated to produce energy, while lower-value waste can be landfilled with proper safeguards. Moreover, technological advancements, such as improved landfill methane capture and cleaner incineration methods, are mitigating some environmental impacts associated with each option.
Landfills and incineration each have significant roles in waste management, but both come with environmental and public health costs. Landfills release methane and risk contaminating groundwater, while incineration generates air pollutants and destroys potentially valuable resources. As societies seek to reduce waste and minimise environmental impact, prioritising waste reduction, recycling, and composting offers a more sustainable solution than relying solely on either landfills or incineration.
🎥 (4:22) Advantages and Disadvantages of Waste Incineration/WELS (Waterpedia Environmental Learning Series)
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REFERENCE
Pollution Solutions Online, July 2021 (viewed 03.11.2024)
FREE Learning Platform for a Better Future (viewed 03.11.2024)
Waterman Engineers Australia (viewed 03.11.2024)
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