Solid waste management activities and impacts
Student worksheet 2 answers

1. Solid waste goes to landfills, or may be incinerated or diverted.
2. The graph demonstrates that waste generation, waste disposal and waste diversion are all increasing.
3. Answers will vary.
4. Landfilling is the disposal of waste on the surface of the earth.
5. Incineration is the controlled process by which combustible wastes are burned and changed into gases and leftover solid material.
6. 95 percent of waste was disposed of in landfills in 2000.
7. 
   

   Disadvantages and avantages of landfills and incineration

   Landfills

   Incineration

   Disadvantages Produces leachate and landfill gasses Leachate may contain a variety of toxic and polluting components, in large or trace amounts If managed improperly, leachate can contaminate ground and surface water Biodegrading waste in landfills produces landfill gas Some components of landfill gas may be toxic or explosive Other components such as ammonia, hydrogen sulphide and other organo-sulphur compounds produce the characteristic bad odor associated with landfills Landfills must be monitored both while they are operating and after they have closed to prevent water entry, limit the migration of landfill gasses and to prevent the growth of disease spreading organisms Advantages Landfills can become a resource not only for gas recovery, but as a recreational area after their closure The recovery of valuable materials from landfills may also be an option in the future

   Disadvantages Produces various types of air pollutants Open burning emits pollutants directly into the air Produces sulphur dioxide and nitrogen oxides that contribute to acid rain The nitrogen oxides it produces can react with VOCs in the presence of sunlight to form ground level ozone, a major component of smog Metals such as cadmium, mercury, chromium, zinc, and nickel may be released as ash Wastewater that requires further cleanup is generated during incineration Contaminated ash must be carefully disposed of to prevent pollution Advantages Reduces the volume of waste being disposed of in landfills Modern incinerators are equipped with pollution abatement devices A potential benefit is energy production through the heat produced through the combustion of solid waste

8. Two forms of waste diversion are recycling and composting.
9. Answers will vary.
10. Recycling reduces the amount of waste disposed. Recycling reduces extraction and production of virgin resources. Recycling generally has less impact on the environment than manufacturing new materials into usable products. For example, recycling aluminum cans saves 95 percent of the energy that would have been required to produce the same aluminum from virgin bauxite.
11. Composting reduces pressure on landfill space by diverting organic waste away from landfills. This means that less organic material is going to landfills and therefore less leachate and odour are being produced. Composting can provide a valuable resource. For example, when added to soil, compost can improve the soils organic matter content, water holding capacity and fertility.
12. Disadvantages of recycling – Recycling operations require energy and water and can produce dust particles, waste water and other emissions. Also, process residues left over from recycling must be disposed of. Finally, recycling programs entail large start up costs and recycling can be more expensive than traditional disposal.
    Disadvantages of composting – If not managed properly compost can cause disagreeable odours and attract pests. Large scale compost facilities must take special care not to contaminate ground or surface water. Airborne bacteria, fungi and other micro-organisms have been found in higher concentrations in and around large-scale composting facilities.
13. Answers will vary. Discuss as a class.
14. Canada imports more hazardous waste then it exports. However, while hazardous waste exports have remained constant, hazardous waste imports are declining.
15. Answers will vary, but may include paint, used motor oil, cleaning products and batteries.