Bio1110 Chapter 30 Managing Solid Waste
  1. Human activity generates waste that sometimes end up in oceans.
    • • Our everyday living and consumption produces Municipal Solid Waste (MSW) - the household trash that must be hauled away and disposed of.

      The U.S. generates more MSW per capita than any other nation.

      Much of this waste can be reused or recycled: paper is the largest component of MSW.

      Note that MSW comprises only 2% of total U.S. waste, which include industrial, agricultural, and mining wastes.

    • The oceans are downhill from everywhere, and debris eventually find their way there.

      Floating debris often collect within gyres - rotating ocean currents.

      Large pools of floating plastics called “Great Pacific Garbage Patch” have been found in the in the North Pacific Gyre, and a “Great Atlantic Garbage Patch” in the North Atlantic Gyre.

      Wildlife can ingest the debris.

    • • Seabirds such as the Laysan Albatross may mistake floating plastic for food.

      Chicks whose parents spent significant time foraging within the “Garbage Patch” may consume more plastic than natural food.

  2. Waste disposal should consider the three R's before waste ends up in landfills or incinerators.
    • • Sound waste management practices seek to minimize the amount of waste that need to be disposed, and comprise three R's.
      • Reduce amount of waste.
      • Reuse items already used.
      • Recycle or recover items.

      The Environmental Protection Agency (EPA) recommends these actions, in order of preference:

      • Source reduction and reuse
      • Recycling and composting
      • Incineration with energy capture
      • Landfilling

      However, more than 50% of U.S. solid waste end up in landfills.

    • Composting is a form of reusing a resource - turning organic waste into mulch or humus and reducing yard waste.

      This can be a pile of brown and green plant-based materials (but avoid animal-based materials) ) that are aerated periodically.

    • Sanitary landfills are engineered to prevent disposed waste from contaminating the environment.

      Liquid leaching down the waste is collected by pipes and pumped into a leachate pond pond for treatment.

      The bottom is lined with plastic and an impervious clay layer that prevents contaminating groundwater.

    • Incineration burns garbage at very high temperatures in a combustion chamber.

      The heat is used to boil water; steam then turns turbines to generate electricity.

      Filters removes toxic gases and particulate matter.

      The remaining toxic ash must be buried in a hazardous waste landfill.

  3. Industrial ecology on a large scale may be one step towards the four R's of consumer choice.
    • Industrial ecology seeks to reduce and reuse waste among industries.

      Waste from one factory can be used for various needs by other industries in an integrated manner.

    • • The four R's of environmentally responsible consumer choice starts with refuse.

      • refuse

      • reduce

      • reuse

      • recycle