Course Content
Introduction to Environmental Chemistry
Environmental chemistry is the study of the chemical and biochemical phenomena that occur in nature. It involves the understanding of how the uncontaminated environment works, and which naturally occurring chemicals are present, in what concentrations and with what effects. Environmental chemistry; is the study of sources, reactions, transport, effects and fate of chemical species in water, soil and air environment as well as their effects on human health and natural environment
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Origin of the solar System
Cosmology; is the branch of astronomy involving the study of the of the universe and the solar system. Cosmo-chemistry ;( chemical cosmology); is the study of chemical composition of the matter in the universe and the process that led to those compositions The solar system is made up of the sun (a star) with nine planets orbiting around it. These planets together with all the other heavenly bodies moving around or between individual planet form members of the solar system. Other heavenly body include; asteroids, comets, meteors, meteorites and satellites such as moon. The solar system does not include other stars .
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Solutions
Solutions are defined as homogeneous mixtures that are mixed so thoroughly that neither component can be observed independently of the other. The major component of the solution is called solvent, and the minor component(s) are called solute.
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Chemical Equilibria
Chemical equilibrium in the environment refers to the state where the rates of forward and reverse reactions of a chemical reaction reach a balance. In this state, the concentrations of reactants and products remain constant over time, although the reactions continue to occur.
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Phase Interactions
Phase interactions in solutions refer to the behavior and changes that occur when two or more substances (solutes and solvents) mix together to form a homogeneous mixture. These interactions are related to the different phases of matter, such as solids, liquids, and gases, and how they interact and transform during the process of solution formation.
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Colligative Properties of Solutions
COLLIGATIVE PROPERTIES OF SOLUTIONS Colligative properties are physical properties of solutions that depend on the concentration of solute particles, rather than the specific identity of the solute. The four colligative properties that can be exhibited by a solution are: 1.Boiling point elevation 2.Freezing point depression 3.Relative lowering of vapour pressure 4.Osmotic pressure
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Introduction To Organic Chemistry
Organic chemistry is the study of carbon containing compounds and their properties. This includes the great majority of chemical compounds on the planet, but some substances such as carbonates and oxides of carbon are considered to be inorganic substances even though they contain carbon.
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Air Quality and Pollution
Air Quality and Pollution
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Introduction To Environmental Chemistry
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The Water Cycle

The hydrosphere is the area of Earth where water movement and storage occur: as liquid water on the surface (rivers, lakes, oceans) and beneath the surface (groundwater) or ice, (polar ice caps and glaciers), and as water vapor in the atmosphere. The human body is about 60 percent water and human cells are more than 70 percent water.

Of the stores of water on Earth, 97.5 percent is salt water (see Figure 1 below). Of the remaining water, more than 99 percent is groundwater or ice. Thus, less than one percent of freshwater is present in lakes and rivers.

Many organisms are dependent on this small percentage, a lack of which can have negative effects on ecosystems. Humans, of course, have developed technologies to increase water availability, such as digging wells to harvest groundwater, storing rainwater, and using desalination to obtain drinkable water from the ocean.

Although this pursuit of drinkable water has been ongoing throughout human history, the supply of fresh water continues to be a major issue in modern times.

 The water cycle is driven by the Sun’s energy as it warms the oceans and other surface waters. This leads to evaporation (liquid water to water vapor) of liquid surface water and sublimation (ice to water vapor) of frozen water, thus moving large amounts of water into the atmosphere as water vapor. Over time, this water vapor condenses into clouds as liquid or frozen droplets and eventually leads to precipitation (rain, snow, hail), which returns water to Earth’s surface.

Rain reaching Earth’s surface may evaporate again, flow over the surface, or percolate into the ground. Most easily observed is surface runoff: the flow of freshwater over land either from rain or melting ice. Runoff can make its way through streams and lakes to the oceans.

In most natural terrestrial environments rain encounters vegetation before it reaches the soil surface. A significant percentage of water evaporates immediately from the surfaces of plants. What is left reaches the soil and begins to move down. Surface runoff will occur only if the soil becomes saturated with water in a heavy rainfall. Water in the soil can be taken up by plant roots. The plant will use some of this water for its own metabolism and some of that will find its way into animals that eat the plants, but much of it will be lost back to the atmosphere through a process known as transpiration: water enters the vascular system of plants through the roots and evaporates, or transpires, through the stomata (small microscope openings) of the leaves.

Ecologists combine transpiration and evaporation into a single term that describes water returned to the atmosphere: evapotranspiration. Water in the soil that is not taken up by a plant and that does not evaporate is able to percolate into the subsoil and bedrock where it forms groundwater.

Groundwater is a significant, subsurface reservoir of fresh water. It exists in the pores between particles in dirt, sand, and gravel or in the fissures in rocks. Groundwater can flow slowly through these pores and fissures and eventually finds its way to a stream or lake where it becomes part of the surface water again.

 Many streams flow not because they are replenished from rainwater directly but because they receive a constant inflow from the groundwater below. Some groundwater is found very deep in the bedrock and can persist there for millennia.

Most groundwater reservoirs, or aquifers, are the source of drinking or irrigation water drawn up through wells. In many cases these aquifers are being depleted faster than they are being replenished by water percolating down from above.

Rain and surface runoff are major ways in which minerals, including phosphorus and sulfur, are cycled from land to water. The environmental effects of runoff will be discussed later as these cycles are described.

Figure 1. Water from the land and oceans enters the atmosphere by evaporation or sublimation, where it condenses into clouds and falls as rain or snow. Precipitated water may enter freshwater bodies or infiltrate the soil. The cycle is complete when surface or groundwater reenters the ocean.

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