Environmental Chemistry : Environmental Chemistry Introduction
CHEM-415
History of Earth : History of Earth A.1 Earth Sun Milky Way Universe The Big Bang + Atmosphere + Hydrosphere + Lithosphere + Biosphere Earth
Slide 3 : A.1 CERN , The Big Bang Poster, 2000.
Slide 4 : A.1 CERN , The Big Bang Poster, 2000.
Slide 5 : A.1 CERN , The Big Bang Poster, 2000.
Origin of Earth : Origin of Earth A.1 CERN, “Back to Creation …”, 2000. 10-43 seconds – Matter = Antimatter
Particles of matter and antimatter (the white circles in the picture) existed in equal portions. Matter was compressed so densely that even light could not travel far and the Universe was opaque. The Universe expanded at a dizzying rate during the so-called “Cosmic Inflation” this explains the large scale uniformity of the Universe today.
10-34 seconds – Strong Force ≠ Electromagnetic & Weak Forces (Matter > Antimatter)
The strong force that binds particles called quarks together into protons and neutrons became distinct from the electromagnetic and weak forces which remained indistinguishable. A high density cosmic soup called Quark Gluon Plasma, QGP existed. Also around this time a tiny excess of matter over antimatter began to develop. It is these survivors that make up our Universe today.
Origin of Earth : Origin of Earth A.1 CERN, “Back to Creation …”, 2000. 10-10 seconds – Protons and Neutrons Form
Between 10-34 seconds to 10-10 seconds the electromagnetic and weak forces separated. The energy of the radiation had also fallen sufficiently to allow protons (red) and neutrons (green) to form as well as short-lived particles, called mesons, made of a quark and an anti-quark (blue).
10-5 seconds – Antimatter “disappears”
Up to about 10-5 seconds, proton and neutron building continued. The remaining antimatter, in the form of positrons disappeared as the radiation energy density dropped below that necessary to create electron-positron pairs.
Origin of Earth : Origin of Earth A.1 3 minutes – Hydrogen, Helium and Lithium Nuclei Form
Things really started to slow down, the Universe was like a giant thermonuclear reactor until, at around three minutes, the reactions stopped leaving a Universe composed of hydrogen, deuterium, helium, and a little lithium. Even today, the universe is made up of about 75% hydrogen and 25% helium, with just traces of heavier elements.
300,000 years – First Atoms Form
During the next 300,000 years the Universe became transparent as photons no longer interacted as soon as they were made. Electrons became captured by the hydrogen, deuterium, helium and lithium nuclei to form the first atoms. CERN, “Back to Creation …”, 2000.
Origin of Earth : Origin of Earth A.1 1000 million years – Galaxies Stars Planets Form
Galaxy formation took 1000 million years as matter began to clump together. Gravity pulled the light elements together to form stars which ignited, producing elements as heavy as iron. Some stars, at the end of their lives, exploded in spectacular supernovae, rapidly generating even heavier elements like gold and scattering them around the Universe. These heavier elements began to clump together into planets around stars. Molecules formed and chemical processes as we know them began.
15,000 million years – Life on Earth Begins
Finally, after 15,000 million years, life begins and people emerge and began to contemplate the Universe around them, trying to piece together the story which led to us being here. CERN, “Back to Creation …”, 2000.
Origin of Earth : Origin of Earth A.1 Proto-planetary ring observed around the star Vega . NASA Drawing showing the formation of planets around a star from its proto-planetary ring
History of Earth : History of Earth A.1 2.4 billion years ago oxygen from bacterial activity started to increase in the earth’s atmosphere. Ref: Universe Today
History of Earth : History of Earth A.1
The History of the Earth : The History of the Earth A.1
The History of the Earth : The History of the Earth A.1
The History of the Earth : The History of the Earth A.1
The History of the Earth : The History of the Earth A.1
The History of the Earth : The History of the Earth A.1
The History of the Earth : The History of the Earth A.1
Today’s Earth : Today’s Earth A.1
Slide 20 : Our Atmosphere
Slide 21 : atmosphere The most fragile part of our environment. Our Atmosphere
Today’s of Earth : Today’s of Earth A.1
Today’s of Earth : Today’s of Earth A.1
Properties of Earth : Properties of Earth A.1
Properties of Earth : Properties of Earth A.1
System and Surroundings : System and Surroundings Scientists and engineers define the subject they study “the system” and the rest of the universe “the surroundings”.
They concentrate on studying the processes taking place within the system and any exchanges of matter and energy with the surroundings. A.1.1
System and Surroundings : System and Surroundings When scientists like chemists, focus on living organisms the processes taking place in the surroundings, the chemistry can be called “environmental chemistry”.
More than ever scientists and engineers are very concerned with how releases from industrial processes (the system) can affect the environment (the surroundings). A.1.1
The Environment : The Environment Atmosphere – several layers, extend up to 500 km above sea level
Troposphere, up to 15 km.
Stratosphere, from 15 km to 50km.
Lithosphere - thin layer of the earth’s crust.
Soil, as thin as one meter, usually 5 meter, rarely more than 20 meters.
Under lakes, one meter to hundred of meters.
Under oceans, one meter to 10 km in ocean trenches.
Mountains, significantly above sea level, up to 8 km.
Hydrosphere – sits on top and under the soil in rivers, lakes, water tables, oceans and frozen in glaciers A.1.1
The Environmental Compartments : The Environmental Compartments Atmosphere – several layers, extend up to 500 km above sea level
Troposphere, up to 15 km.
Stratosphere, from 15 km to 50km.
Lithosphere - thin layer of the earth’s crust.
Soil, as thin as one meter, usually 5 meters, rarely more than 20 meters.
Under lakes, one meter to one hundred of meters.
Under oceans, one meter to 10 km in ocean trenches.
Mountains, significantly above sea level, up to 8 km.
Hydrosphere – water sits on top and under the soil in rivers, lakes, water tables (underground), oceans and frozen in glaciers A.1.1
Environmental Chemistry : Environmental Chemistry When studying an environmental case we need to avoid studying the subject as a closed system, an environmental approach should see it as a part of the larger and highly interconnected set of environmental compartments. A.1.1
What this course is not : What this course is not This course is not about:
Environmental analysis
How to analyze components in the environment.
Environmental toxicology
How organisms, specially humans, are affected by the environment.
Environmental controls
How technology and legislation are used to control exposure and releases into the environment. A.1.1
What this course is about : What this course is about Reviews the chemical basis for understanding our surroundings.
Develops an understanding of the composition of the natural environment and the interconnectivity among its different compartments. A.1.1
What this course is about : What this course is about Develops skills to be able to use known chemical and physical processes in each of the environmental compartments to predict fate of a pollutant.
Increases understanding of contributions of a variety of human activities that affect and change the natural environment. A.1.1
Environmental Composition : Environmental Composition In order to learn about a particular part of the environment it is logical to name the components and their relative amounts.
Being familiar with the ways in which the composition can be expressed and the units used becomes crucial in developing a qualitative and quantitative understanding. A.1.2
Aqueous Solutions : Aqueous Solutions Think of examples of aqueous solutions in the environment.
Describe its components.
Describe how the concentration of these components can be expressed. A.1.2.1
Solids and Gases : Solids and Gases Think of examples of aqueous solutions in the environment.
Describe its components.
Describe how the concentration of these components can be expressed. A.1.2.2
Species Distribution : Species Distribution It is usually insufficient to only know the total quantity of a chemical substance in order to judge its environmental effect.
Most substances are found in more than one form, therefore it is crucial to know the actual species distribution.
The species distribution can be found by in situ chemical analysis or using a distribution diagram. A.1.2.4
Distribution Diagrams : Distribution Diagrams They can be based on analytical data or thermodynamic equilibrium constants.
The distribution diagram is as good as the thermodynamic data used.
This type of diagram assumes that the system would reach equilibrium, which in some cases might be problematic. A.1.2.4
Distribution of Carbonate Species : Distribution of Carbonate Species Alpha represents the fraction of the chemical species at any give pH.Alpha = [individual species] / [all species (for a given component) Alpha
Mercury Speciation : Mercury Speciation Average concentration of chloride in the ocean 0.56 M.28% HgCl42-, 56% HgCl3-, 16% HgCl2.
Average concentration of chloride in well water 2.7 x 10-4 M.100% HgCl2.
Web References : Web References CERN, “CERN; Photo Packs; Back to Creation - the Big Bang”, http://outreach.web.cern.ch/outreach/public/cern/PicturePacks/BigBang.html Friday, September 29, 2000 4:42:13 AM
CERN, “Back to Creation - the story of the Big Bang”, http://outreach.web.cern.ch/outreach/public/cern/PicturePacks/BigBang/captions.html Friday, September 29, 2000 4:58:13 AM
JPL, “SIRTF to lift veil on planet formation”, http://planetquest.jpl.nasa.gov/news/sirtf_extrasolar.cfm, August 19, 2002