SVN3M – Waste Management

Introduction to Waste Management Reading Assignment

Read pp. 77-82, 84, 86 (top)

Answer the questions in the space provided.

Questions:

  1. What is “precycling”, and how is it different from recycling? (p. 77)

Precycling – prevent or reduce waste by thinking about consumption habits, products bought and packaging

Recycling – remanufacture of a material after it has been used

  1. How much household waste does the average Canadian produce yearly? (p. 7) What comparison or image would you use to help yourself or family and friends visualize this amount of waste?

1019 Kg equivalent in mass to a small automobile (a Smart car)

  1. Complete the following table comparing the pros and cons of the 3Rs and composting (pp. 79-80):

Form of Waste Diversion / Pros / Cons
Reduce / Creates less garbage at the source / Difficult to change consumption patterns and lifestyle
Reuse / Materials require little or no additional processing, extends life of products / Eventually must be disposed of or diverted, some things difficult to re-use without additional processing
Recycle / Common, widely accepted as consumer behaviour (80% Canadian households) / Collection and processing of material uses energy, produces pollution; encourages consumption?
Compost / Natural cyclical process, enriches land / Personal composting requires commitment; odour from large-scale facilities
  1. How much of our waste is organic matter that can be significantly reduced by composting? (p. 80)

Approximately 20 – 30%

Questions 5-7 are concerned with landfills (p. 81-82)

  1. What is a landfill? From Figure 5 (p. 81), what are the layers in a typical landfill design?

A landfill is: a large tract of land where garbage is stored

Layers in a typical landfill design are:

Layers: cells, soil, drainage layer, gravel, fibre mat (protection for plastic liner), plastic liner, water (leachate) collection pipe, compacted clay liner, leachate collection pond

  1. What is leachate?

water and other liquids that percolate down through the garbage

  1. What are 2 concerns with landfills mentioned in the reading?

◊ Liner leakage – contamination of groundwater

◊ Must be monitored and maintained for decades after closing (breakdown of garbage is not the main purpose)

Questions 8-10 are concerned with incineration (p. 84)

  1. What is advanced thermal treatment (ATT), and how is it different from incineration?

ATT – extremely high temperature applied to organic matter, either in the absence of oxygen (pyrolysis) or with small amounts of oxygen (thermal gasification)

  1. What are the advantages of incinerators or ATT over landfills?

gases produced (methane, hydrogen) can be used as fuel to generate heat and electricity (cogeneration); significantly reduces solid materials to be put into landfills

  1. What are 3 concerns with incinerators or ATT?

◊ justifies disposing organic matter in garbage (reduces consumer guilt);

◊ leftover residue is still toxic which may leach into groundwater;

◊ waste of resources/materials; still produces hazardous products (mercury, lead, dioxin)

  1. What is biodegradation?

breakdown of organic matter by living things (bacteria, fungi, insects, worms) so that nutrients are available for other living things

  1. What is the difference between anaerobic digestion and aerobic digestion? Give 1 example of where each kind of biodegradation is used.

Anaerobic digestion (in the absence of oxygen) – often used on cattle or hog farms for manure

Aerobic digestion (exposure to air) - used in composting and wastewater facilities