EPSc 116: Resources of the Earth

Lecture 12 on Ch. 4: Environmental Impacts

Focal Points

Environmental consequences of 1) extraction of resources, 2) processing of resources, 3) use of resources, and 4) disposal of waste products (from manufacturing or consumer usage).Impacts may be subtle, delayed in result, or removed from site of usage. Coping with environmental concerns 1) Recognize HOW problems arise (e.g., inherent nature of the material, choice of the processing). 2) Avoid problems. 3) Clean up problems that were created (understand HOW).

Aspects of Environmental Impact of Resource Handling

Exploration: Search for economically profitable deposits of resources, e.g., through geologic field mapping aerial surveys using remote sensing by instruments (reflectivity, spectroscopy) collection of soil samples for laboratory analysis drilling of rock cores for geologic and chemical analyses

Exploitation: Removing and preparing the samples for eventual end use mining quarrying dredging drilling processing and smelting

Usage: burning of fossil fuels, use of nuclear fuels, pollution from processing of materials, need for eventual disposal of items no longer needed

Disposal/Recycling: industrial, e.g., from original processing, later manufacturing individual, e.g., unwanted items, packaging materials

Mining Involves Removal of Huge Amounts of Waste Rock

Text, Fig. 4.4

http://jcwinnie.biz/wordpress/?p=2664

Acid mine drainage from metal sulfidedeposits in Rio Tinto, southern Spain

Acid Mine Drainage

Sulfide minerals react with oxygen andwater to produce sulfuric acid H2SO4 andiron oxide minerals similar to rust (thus,the red-orange color). The rust-likeparticles coat the rocks and streambottom, and foul the gills of the fish. Theacid also kills plants and fish.

“CH2O” means organic materials, e.g., coal, grass-cuttings, wood chips. “Me” = metal, such as iron.The reaction shown above simply “undoes” what happened during development of acid mine drainage:

1) Metal sulfide minerals, e.g., FeS2 pyrite, were oxidized to metal sulfates (SO4 minerals) and sulfuric acid.2) Remediation here involves taking the metal sulfates and “reducing” them back to metal sulfides (which are very insoluble, so they remain undissolved and do not release toxic metals back into the water)

Remediation of Acid Mine Drainage (1)

2 cm

Cartilage

Bone

Apatite IITM Cleaned Pollock

Bone = calciumphosphate

Calcium phosphate +metal = metal phosphate (insoluble)

Before and After Views of Different Mining Sites

Remediationis possible.

In the modernpermittingprocess,plans forremediationare demandedbefore anynew miningcan begin.

Remains of coalstrip mining.

BP’s oil spill in the Gulf, as seen from a NASAsatellite. May 14, 2010. http://en.wikipedia.org/wiki/File:Deepwater_Horizon_oil_spill_-_May_24,_2010_-_with_locator.jpgGulf of Mexico

Another Aspect of Mine Waste, again Geologically Imposed

Text Fig. 4.19, top

Text, Fig. 4.19, bottom

Mining Waste, Geologically and Economically Controlled

$1258/ounce 3/2016

$1326/ounce 3/2018

Burning of Fossil Fuels Releases Particles and Gases

Many of the release products have been reduced in abundance in the emissions due to better technology.

The major public concerns today are CO2 (greenhouse gas) and mercury (Hg) release.

Text, Fig. 4.22, top

Minute particulates (from cars, industry, power plants) are of increasing concern (lung problems).

Text, Fig. 4.22, bottom

This explains the focus on energy-production.

www.sciencelearn.org.nz/Contexts/Enviro-imprints/Sci-Media/Images/Temperature-inversion

http://www.martinfrost.ws/htmlfiles/great_smog.html

London Fog of 1952December 4, 1952 – March, 1953

Smog, Photochemical Smog, and Temperature Inversion

Smog = soot + fog. Particles + chem.

http://www.mercuryinschools.uwex.edu/lib/images/curriculum/hg_deposition.gif

MercuryContamination

http://health.state.tn.us/images/mercury2.jpg

It is a major problem whenmercury bonds with carbon andforms a so-called organiccompound calledmethylmercury. This compoundis ingested by and accumulatesin fish, which we then can eat. Mercury is a toxic heavy metal.

Mercury gets into theenvironment due to naturalprocesses, our processing ofmetals such as gold, and releaseby the burning of coal.

Greenhouse Effect

Energy from the sun has a wide range of wavelengths. About 70% of sun’s incoming light reaches Earth’s surface. The surface heats and re-radiates energy at longer wavelengths than incoming rays that passed through our atmosphere.

Longer-wavelength (red arrows) is better absorbed than shorter-wavelength radiation, especially by ”greenhouse” gases, such as water (clouds), CO2, and CH4 (methane, natural gas).

The earth therefore becomes warmer: Greenhouse Effect.

Problems

Acid attack on buildings

Acidification of surface water

Destruction of vegetation

SO2 + H2O H2SO4

Sulfuric acid

Acid attack on marble (calcite)

Municipal Solid Wastes in the US, 2012

Source: EPA

Other 3.4%

Other 4.3%

Recent Changes in Generation and Disposal of Municipal Waste

discarded

Amount of discarded (“landfilled”) material increased until about 1989. Since then, increasingly larger proportions of waste materials have been recycled, composted, or burned for energy.

Text, Fig. 4.35(b)

http://tonto.eia.doe.gov/energyexplained/?page=biomass_biogas

http://www.calrecycle.ca.gov/Archive/IWMBAR/2000/Images/ModLandfill.gifhttp://www.calrecycle.ca.gov/Archive/IWMBAR/2000/Images/ModLandfill.gif

LandfillsModernlandfill

Historic landfill

http://www.calrecycle.ca.gov/Archive/IWMBAR/2000/Images/HistLandfill.gif

See textFig. 4.37

Recycling of Scrap is Big-Business

www.mciworldwidetrading.com/

Recycled Cell Phones:

A Treasure Trove of Valuable Metals**

** From United States Geological Survey fact sheet of the same name.

$0.63

Handling of Liquid Wastes

-- Sewage and domestic wastewater are major human products

-- Undesirable components in wastewater: bacteria, nutrients for algae, toxic chem.

-- Treatment: filtration, decomposition, disinfection, special removal processes

-- Dump or re-use cleaned sludge, e.g., as agricultural fertilizer

-- Special problems: petroleum-based effluents (industrial, your car’s oil change)

-- “Natural solution”: sediments filter waste water; oxygen breaks down undesirables

-- Negative effects on the natural water environment:

Biological oxygen demand

Eutrophication (from excessive influx of nutrients, followed by algal bloom)

Microbes that are harmful to human health

-- Problems with unwise legislation; need appropriate scientific input (chemists, geol.)

--Industrial ecology: Think through the recycling issues even before designing new products. Create a closed loop in the usage of the material components.

2016: Flint, Michigan’s problems with lead

Take-Home Messages

Multiple reasons to mine, process, and use resources wisely: Many resources have a limited availability. It requires energy (another resource) to mine, process, transport, manufacture. There are many sources of waste-production in the use of resources. Some of those wastes severely degrade the safety of the environment and the organisms that live in it.

Reduce, re-use, re-cycle. There are environmental and economic benefits.

Consider both up-front (selection of materials and processes, industrial ecology) and after-the-fact solutions (scrap retrieval, recycling; remediation) to the challenges of resource retrieval and use.