LEC_12

Sanitary Landfills

  • Definition: In sanitary landfills, waste is buried in the ground or piled up in large, carefully engineered mounds.

  • Waste Management:

    • Waste is compressed and interlayered with soil to reduce volume and manage decomposition.

    • Heavy-duty plastic liners and an underlying layer of permeable clay are utilized to prevent contaminants from seeping into the ground.

Drawbacks of Landfills

  • Leachate Concerns:

    • Leachate is the liquid resulting from the dissolution of substances in trash as rainwater percolates downward.

    • Liners can be punctured, which allows leachate to contaminate surrounding environments, threatening water and soil quality.

Incineration

  • Process Overview:

    • Incineration or combustion involves burning mixed garbage at very high temperatures in a controlled process.

  • Advantages:

    • Reduces both the weight and volume of solid waste, making it easier to manage.

  • Disadvantages:

    • Does not eliminate toxic components of trash; hazardous chemicals can be released into the atmosphere during burning, posing health and environmental risks.

Circular Economy

  • Concept:

    • Transitioning from a linear economy (raw materials to products to waste) to a circular economy.

    • Utilizes waste products as raw materials for new manufacturing processes, minimizing waste.

Waste Generation Trends

  • Global Consumption Trends:

    • Increased consumption leads to increased waste generation, correlating with a higher standard of living.

    • The phenomenon of 'throw-away' society, where consumers discard items that could still be reused.

  • Statistical Projections:

    • Over three decades, per capita waste generation rates have significantly increased in developing regions.

    • The World Bank estimates waste generation will rise from 20.1 billion tonnes in 2016 to 3.40 billion tonnes by 2050.

    • More than 33% of this waste is globally mismanaged, resulting in the degradation of water and soil quality.

Here are some short answer quiz questions based on the topics covered in the notes:

  1. What is the primary purpose of a sanitary landfill?

    • to compress the waste to reduce the volume and minimize the impacts on the environment

  2. What material is used as liners in sanitary landfills to prevent leachate from contaminating the soil?

    • to prevent leachate from contaminating the soil

    • heavy duty liners are placed to to protect the surrounding underground water ways

  3. Define leachate.

    • results from liquid coming out of the garbage as it breaks down and it can sometimes contain toxic chemicals

  4. Describe the incineration process and its primary disadvantage.

    • Burns mixed garbage at high temperatures

    • and causes the air to become very polluted and realizes harmful emissons

  5. What is a circular economy, and how does it differ from a linear economy?

  6. How have global consumption trends affected waste generation rates?

    • consumption trends are going up

    • more people are buying which means more things are being thrown out

  7. What does the World Bank project about waste generation by 2050?

    • protected to be 3.40 billion tonnes