Water Characteristics Measurements

We will present a three part series on the topic “Water Characteristics Measurements”. In this weeks reading we will focus on Water Temperature and PH. This information could be most useful to science students.

Water characteristics can be measured using several scales. This series of articles will look at these different measurements with a view towards assisting our youngsters to better understand the properties of water. Water temperature, PH, specific conductance, turbidity, dissolved oxygen; hardness and suspended sediments are all used as common water characteristic measurements.

Water temperature: Everyone on a daily basis use Water; some have more use for water than others. Divers, fishermen, power plants and beverage industries all have use for large volumes of water. For these purposes water must be at the right temperature to gain desired results. In the case of power plants water temperature will change as the process of providing electricity begins with cool water and the release of warmer water back into the environment.

PH: PH is the measure of how acidic water can be and gives an indication of the relative amount of free hydrogen and hydroxyl ions present in water. The scale of this measurement goes from 1-14 with 7 being the neutral number. If the PH of water is measured and it is found to be less than 7 it means that the water is very acidic, if the measurement goes over 7 it indicates that it is a base. PH is measured in logarithmic units as is done when earthquakes are measured with each number representing a 10-fold change in the acidity and basicity of the water. This means that water with a PH of 5 is ten times more acidic than that with a PH of 6.

Specific Conductance: This might be especially interesting to our science students who are interested in experiments. This has to do with the ability of water to conduct electricity. Salt water for example will have a high specific conductance because of the dissolved solid, which is salt that is present in the water. Rainwater will also indicate high specific conductance because of the dissolved airborne dust and gases in the atmosphere. Distilled water on the other hand will indicate low specific conductance because of its purity. For those of you that are privy to the use of a laboratory attempt the hookup of a battery to a light bulb and attach wires to water that is saline and then try pure water to see what will occur.

Turbidity: Turbidity is the amount of particles that are in the water, which makes the water cloudy or opaque. These can include, clay, silt, finely divided organic and inorganic matter, soluble colored organic compounds, plankton and microscopic organisms. Turbidity is reported in nephelometric turbidity units (NTU) and is measured by shining a light through the water.

Dissolved Oxygen: Up to about ten molecules of oxygen per million parts of water is actually dissolved in water. Fish and Zooplankton breathe this oxygen for their survival. Water that moves rapidly is high in oxygen while stagnant water has less oxygen, which will make it difficult for aquatic life to flourish.

Hardness: This is a term used to describe the quality of some water. You can recognize hard water when it becomes difficult to work up lather while bathing and or washing. Hard water can destroy equipment and in highly industrialized countries it will be necessary to institute measures to soften the water.

Suspended Sediment: This is the amount of soil moving along in a stream. This will occur during heavy rains when there is erosion of riverbanks or in areas where mudflows are prevalent.  Fast flowing water will pick up large amounts of sediments and when deposited into streams, rivers and lakes, it can present long term water quality problems as these sediments settle at the bottom of these water bodies.

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