Glossary

Glossary

Here is a list of terms and definitions which you may find helpful.

Abiotic: Independent of life or living things: An ecosystem involves interactions between abiotic and biotic factors ... The abiotic environment includes physical and chemical factors which affect the ability of organisms to live and reproduce. (Dictionary of Science)

Algal bloom: A dense mass of very small, aquatic organisms, such as plankton, easily visible to the eye. (Dictionary of Science)

Algal die-off: When aquatic conditions are no longer favorable causing a considerable decrease in the number of organism responsible for the algae bloom, usually visible to the eye.

Anacharis : A fresh water plant.

Biotic: Having to do with life or living things; produced by or involving living organisms; Biotic factors are all the living things that directly, or indirectly, affect the environment ... Biotic factors interact ... in nutritional relationships and symbiotic relationships. (Dictionary of Science)

The level of Dissolved Oxygen in natural waters is often a direct indication of quality, since aquatic plants produce oxygen, while microorganisms generally consume it as they feed on pollutants. At low temperatures the solubility of oxygen is increased, so that in winter, concentrations as high as 20 ppm may be found in natural waters; during summer, saturation levels can be as low as 4 or 5 ppm. Dissolved oxygen is essential for the support of fish and other aquatic life and aids in the natural decomposition of organic matter. Waste treatment plants which employ aerobic digestion must maintain a level of at least 2 ppm dissolved oxygen. This is usually accomplished by mechanical aeration. At elevated temperatures, oxygen is highly corrosive to metals, causing "pitting" in ferrous systems such as high-pressure boilers and deep well oil recovery equipment. To prevent costly corrosion damage, the liquids in contact with the metal surfaces must be treated, usually by a combination of physical and chemical means. Deaeration (to remove air or gas from) can reduce the dissolved oxygen concentration of boiler feedwater from several ppm to a few ppb. Chemical reducing agents such as hydrazine or sodium sulfite are sometimes used instead of deaeration, but more often are used to react with residual oxygen which remains after the deaeration process. (http://www.chemetrics.com/)

Elodea : A fresh water plant.

Hydrometer: A graduated instrument for finding the specific gravity of liquids. A hydrometer is used to determine the concentration of acid in a storage battery or to test the purity of milk, the strength of alcohol or salt in a substance, etc. A hydrometer ... consists of a glass tube with a bulb syringe for sucking up samples of the electrolyte. Within the glass tube is a calibrated float. The depth to which the float sinks is a measure of the specific gravity of the solution. (Dictionary of Science)

Methodology: The system of principles, procedures, and practices applied to a particular branch of knowledge. The branch of logic dealing with the general principles of the formation of knowledge. (Webster's Dictionary)

Nitrate is the most completely oxidized form of nitrogen. It is formed during the final stages of biological decomposition, either in wastewater treatment facilities or in natural water supplies. Inorganic nitrates such as ammonium nitrate are commonly used as fertilizers. Low-level nitrate concentrations may be present in natural waters. However, a maximum of 10 ppm nitrate nitrogen is allowed in drinking water supplies. Excessive nitrate concentrations may indicate the presence of heavy fertilizer runoff or excessive discharge from a waste treatment facility. (http://www.chemetrics.com/)

The measurement of pH is one of the most frequently performed water quality determinations. Water softening, precipitation, disaffection and corrosion control are some of the many operations which depend on the careful measurement and control of pH. While there are many methods available to the analyst for measuring pH, colorimetry has long been recognized as one of the most accurate. Great precision is attainable through the use of indicators which change color over a very narrow range of pH. Another important advantage of this technique is the fact that no standardization, calibration, or temperature compensation is necessary, making it especially useful in the field. (http://www.chemetrics.com/)

Phosphorus occurs naturally in rock formations in the earth's crust, usually as phosphate. Of high nutritive value to plants and animals, phosphates are used in fertilizers and as animal feed supplements. They are also used in the manufacture of industrial chemicals and pharmaceuticals and as detergent builders. High phosphate concentrations in surface waters may indicate fertilizer runoff, domestic waste discharge, or the presence of industrial effluents or detergents. Although phosphates from these sources are usually poly-phosphates or organically bound, all will degrade to "ortho" or reactive phosphates with time. If high phosphate concentrations persist, algae and other aquatic plant life will flourish eventually causing decreased dissolved oxygen levels in the water due to the accelerated decay of organic matter. Phosphate measurement is used to control scale and corrosion inhibitor levels in boilers and cooling towers. (http://www.chemetrics.com/)

Raw Environment: An aquarium environment that is in a natural condition; has not been refined or processed.

Sampling Techniques: The systematic procedure by which a complex or scientific task (sampling) is accomplished. (Webster's Dictionary)

Specific Gravity: (relative density; specific) the ratio of the density of a substance to the density of some reference substance. For liquids or solids it is the ratio of the density (usually at 20 degrees Celsius) to the density of water (at its maximum density). (Concise Science Dictionary)

Test Consistency: Conforming to the same principles of course of action when conducting quantitative measurements: uniform. (Webster's Dictionary)

Turbidity is one of the most important parameters used to determine the quality of drinking water. The World Health Organization specifies 5 NTU (Nephelometric Turbidity Units) as the reference value of water for trade. The USEPA has recently adopted a final ruling that will implement new standards for turbidity in drinking water beginning in 1998— acceptable limits will drop from 5 NTU to 1 NTU for facilities serving more than 10,000 people. Turbidity measurement is also a requirement of wastewater treatment. (http://www.chemetrics.com/)

Variable (experimental) : A factor in an experiment that is subject to change, i.e., can occur in more than one state (Dictionary of Science);