|
|
This is only a preview of the paper
Click here to register and get the full text.
Existing members click here to login
|
|
|
ABSTRACT
The study was aimed to characterize the physico-chemical and biological properties of water and compare these parameters for samples taken from freshwater, saltwater and polluted systems. ... The following parameters were investigated for each water sample: turbidity, temperature, pH, color, presence of solid residues, dissolved oxygen (DO), amount of free carbon dioxide and total hardness. Results show that the parameters vary among the different water samples. Turbidity was shown to be greater for polluted water due to the high level of impurities it contains compared to freshwater and theoretically, saltwater. Consequently, the amount of solid residues was greatest for polluted water. Temperature was shown to be higher for polluted water and theoretically, lowest for saltwater due to the latter’s colligative properties. ... Experimental data shows that both freshwater and polluted water exhibit a pH range of 6-7. Dissolved oxygen was experimentally observed to be greatest for polluted water, but theoretically, it should be lowest due to the smaller population of organisms inhabiting this kind of system. The amount of free carbon dioxide, as well as total hardness (measured in mg/L CaCO3) was determined to be greatest in polluted water.
INTRODUCTION
Water plays an important role in an ecosystem. The quality of water is an important component in the study of ecology. The quantity and quality of water determines the type of ecosystem a place can support since it influences the overall characteristics of an environment and the distribution of plants and animals in it.
This laboratory exercise aims to acquaint students with various physico-chemical tests for the analysis of water quality and the concepts involved which are necessary in the study of ecology.
Turbidity is the measure of the degree to which light is scattered by suspended particulate material and soluble colored compounds in the water. It provides an estimate of the muddiness or cloudiness of the water due to clay, silt, finely divided organic and inorganic matter, soluble colored organic compounds, plankton, and microscopic organisms. The greater the amount of total suspended solids (TSS) in the water, the murkier it appears and the higher the measured turbidity
Sources of turbidity are phytoplankton, clays and silts from shoreline erosion, resuspended bottom sediments and organic detritus from stream and/or wastewater discharges. Dredging operations, channelization, increased flow rates, floods, or even too many bottom-feeding fish may stir up bottom sediments and increase the cloudiness of the water. ... Nephelometric refers to the way the instrument estimates how light is scattered by suspended particulate material in the water.
Temperature also influences water chemistry. ... An important example of the effects of temperature on water chemistry is its impact on oxygen. Warm water holds less oxygen than cool water, so it may be saturated with oxygen but still not contain enough for survival of aquatic life. ... The sun can heat a greater proportion of the water in a shallow lake than in a deep lake and so a shallow lake can warm up faster and to a higher temperature. Lake temperature also is affected by the size and temperature of inflows and by how quickly water flushes through the lake. ...
The pH of a sample of water is a measure of the concentration of hydrogen ions. The pH of water determines the solubility and biological availability of chemical constituents such as nutrients (phosphorus, nitrogen, and carbon) and heavy metals (lead, copper, cadmium, etc. ... For example, in addition to affecting how much and what form of phosphorus is most abundant in the water, pH may also determine whether aquatic life can use it. ... Photosynthesis uses up dissolved carbon dioxide which acts like carbonic acid (H2CO3) in water. CO2 removal, in effect, reduces the acidity of the water and so pH increases. In contrast, respiration of organic matter produces CO2, which dissolves in water as carbonic acid, thereby lowering the pH. ... Electrical conductivity (EC) on the other hand estimates the amount of total dissolved salts (TDS), or the total amount of dissolved ions in the water. ... A bigger watershed to lake surface area means relatively more water draining into the lake because of a bigger catchment area, and more contact with soil before reaching the lake. ... Evaporation of water from the surface of a lake concentrates the dissolved solids in the remaining water thurs resulting to higher EC. ... Oxygen concentrations are much higher in air, which is about 21% oxygen, than in water, which is a tiny fraction of 1 percent oxygen. Where the air and water meet, this tremendous difference in concentration causes oxygen molecules in the air to dissolve into the water. More oxygen dissolves into water when wind stirs the water; as the waves create more surface area, more diffusion can occur.
Approximate Word count = 3904
Approximate Pages = 15.6
(250 words per page double spaced)
|
|
|
|
|
|