-acid mine drainage from tailings -acidic and toxic mining wastewater Minimizing impact of mining: -must have knowledge -environmental regulations (forbid bad mining practices, clean air act, etc) -land reclamation activities -Use of new biotechnology mining Why recycle: -toxic to humans -dangerous to natural ecosystems -degradation of air, water, and soil -use of land for disposal -aesthetically undesirable Most recycled metals: iron and steel, 90 percent by weight -one third of energy needed as regular process to produce with recycled steel Sustainability: is a long-term strategy for consuming resources Ways to be more sustainable: -alternatives for scarce resource -use raw materials more efficiently
Chapter 15: Energy Resources 13:23 Peak oil: the time when half of Earth’s oil is extracted and used Energy resources are the fundamental lifeblood for industry Growing challenge: how to break energy dependency and retain high standard of living Energy Shocks: constant worries from past to present and to the future over the price, dependency, power failures Renewable energy -solar, hydropower, biofuels, wind power Fossil fuels make up 90 percent of us energy consumption Fossil fuels are nonrenewable resources Peak increase during 1950-1974, has decreased since then Types of energy: Light, electrical, chemical, thermal, mechanical, and nuclear Energy unit: capacity to do work -Joule: 1 newton force over 1 meter -1 gigajoule: 10^9 J -1 exajoule: 10^18 J -1 BTU=heat for 1lb of water 1 degree Power -1 watt per second Fossil fuels: -coal -petroleum -natural gas America has more coal than any other fossil-fuel resource -20 percent of total US energy consumption -More coal reserves than any other single country in the world -1/4 of world’s coal is in US -Large coal in 38 of 50 US states Coal is transformed plant matter deposited in ancient swamps Classification based on caloric content and combustion: -lignite, subbituminous, bituminous, anthracite With increase in rank, higher carbon content, higher caloric values, less volatile gas World reserves about 1000 BMT of coals China, US, Russia account for 50 percent of world’s co2 released
Chapter 15: Energy Resources 13:23 Environmental impacts of coal: -land disturbances from open-pit and strip-mining -acid drainage -Subsidence over subsurface mines -Surface water and groundwater pollution -Air pollution from thermoelectric power plants -Disposal of coal ash -Area ecosystem degradation Hydrocarbons: oil and gas -Natural gas is mostly methane (CH4) -oil and gas formed from transformation of organic matter -Heavily mined through production wells -Other forms: oil shale and tar sands Formation of O and G through geologic processes
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