Chemistry Water quality testing Essay

The alma of the experimental Investigation was to gather four dissimilar water samples and test them In several different methods to see which water sample had the best quality. The tests that were used were that of: A fecal chloroforms test, phosphate test, nitrates test, pH test, dissolved oxygen test and a total dissolved solids test. It was thought out that filtered water would hold the highest standards, the most sanitary water samples was that of tap water, then followed by filtered, then tank (rain) water and creek water respectively. The three water samples of tap, altered and tank water were all relatively close to one another in relation to quality, whereas creek water was moderately distanced from the rest of the samples). Hypothesis: If four different water samples are tested (using 6 different tests) for the drinking water quality parameters, the following would be found: the filtered water would best fulfill the standards of cleanliness, followed by tap water, then tank (rain) water and finally creek water. Introduction: Water quality refers to the chemical, physical and biological characteristics of water.

It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose. It is most frequently used by reference to a set of standards against which compliance can be assessed. The most common standards used to assess water quality relate to health of ecosystems, safety of human contact and drinking water. 71 percent of the earth’s surface is made up of water, the universal solvent, and of that amount, 97. 5 percent of the water is that of salt water (which would require desalination to become drinkable), leaving only 2. Recent of fresh drinking water, but it Is not always safe. Sickness due to water consumption Is very common and ongoing problem, which Is why water Is now thoroughly being tested. These tests performed Involved a Fecal Chloroforms test, Phosphates test, Nitrates test, pH test, Dissolved Oxygen’s test and Total Dissolved Solids test. The Fecal Chloroforms involves testing water samples, and are capable of growth in the presence of bile salts or similar surface agents, are oxides negative, and produce acid and gas from lactose within 48 hours at 44 В± 0. ICC. The Phosphates test involves testing water for human waste/pollution.

Sources of phosphorus include human and animal wastes, industrial wastes, soil erosion, and fertilizers. The Nitrates test involves is a chemical test used to determine the presence of nitrate ion in solution by adding nitrate regent to a water sample. The pH test involves testing a water sample to see how acidic or alkaline a substance Is. Indicators like universal indicator change color depending on whether a substance Is acid or alkaline. Universal Indicator Is particularly useful because It changes to a range of different colors, so tells us how acidic, or how alkaline a substance Is.

If It changes red, orange or yellow (pH 1-6), it tells us the substance is acidic. A color change of substance is neutral (pH 7). The Dissolved Oxygen’s test involves measuring the amount of gaseous oxygen (02) dissolved in an aqueous solution. Oxygen gets into water by diffusion from the surrounding air, by aeration (rapid movement), and as a waste product of photosynthesis. The Total Dissolved Solids test involves measure of the combined content of all inorganic and organic substances contained in a liquid in molecular, unionized or micro-granular suspended form.

Generally the operational function is that the solids must be small enough to survive filtration through a filter with two-micrometer pores. Equipment: Beaker McCracken Agar plates Glass Stirrer Pipette Bunsen Burner Nitrate Testing kit Phosphate Testing kit Incubator Britain filter Electronic Equipment: Data Logger Turbidity Tube Chemical(s): Ethanol Method: Fecal Chloroforms Test: 1 . The Bunsen Burner was set up and the glass spreader was applied with ethanol. 2. The glass spreader was flamed to sterilize it and remove any contaminating bacteria. 3.

The pipette was used to place water on agar plate. . The glass spreader was used to spread the water sample over the agar plates. 5. The agar plates were closed and sealed with sticky tape. 6. The agar plates were placed in the incubator and left for 48 hours. 7. Once the plates had been incubated for 48 hours, they were observed and the FCC colony forming units were counted. Phosphate Test: 1. 1. The cap was removed from the plastic vessel. The vessel was then rinsed with water. 2. A water sample was then added and filled up to the 10 ml mark. 3. Packet of HI 3833-0 Phosphate Reagent was then added to the water sample. 4. The cap was replaced and the solution was mixed until the solids had dissolved. 5. The cap was removed and the solution was transferred into the color comparator cube. 6. The sample was left to set for 1 minute in the comparator cube. 7. The color matching the sample within the tube was determined and the result was recorded. 8. This process was further repeated for the remaining water samples. Nitrates Test: 1. The glass test tube was filled with 10 ml of the water sample, up to the mark. . One packet of the HI 3874-0 Nitrate reagent as added to the sample. 3. The cap was placed and the glass test tube was shaken vigorously for exactly one minute. 4. The sample was left for four minutes, to allow the color to develop. The cap was then The cube was held in front of a white piece of paper in order to accurately determine which color matched the color of the water sample. 6. The process was repeated on each of the remaining water samples. PH Test: 1. A small quantity of the first sample was poured into a glass beaker. 2.

It was then stirred with the glass stirrer. 3. The pH probe was connected to the data logger and the liquid bottle was unscrewed from the pH probe. . The pH probe was placed into a beaker and the results were recorded. 5. The method was repeated a further three times with the other samples. Dissolved Oxygen Test: 1. A small quantity of the first sample was poured into a glass beaker. 2. The DO probe was connected to the data logger and the liquid bottle was unscrewed from the DO probe. 3. The DO probe was placed into a beaker and the results were recorded. . The method was repeated a further three times with the other samples. Total Dissolved solids (ADS) -rest: 1 . All of the measuring cups were rinsed out and wiped down. 2. One cup was filled with filtered, one with tap, another with creek and the last with rainwater (The amount of water in all cups were equal to gain a successful calculation). 3. With use of the Total Dissolved Solids testing tube (ADS Probe), the first cup of water was tested for its quality. The probe was then removed, and gave a reading, measured in pump (parts per-million). . After cleaning the ADS probe, the third step was repeated with the other 3 water samples. 5. After the data for all the water samples were collected, the following formula was used for each of the water samples to find the ejection rate percentage of parts that were not H2O: Number (measured in micro Siemens) x 0. 65 to give an answer in parts per-millions (pump). 6. These results were recorded. Safety Assessment: Although the risks whilst doing the tests were minor, they can still be dangerous if not treated respectively.

Risks were as follows: Electrical equipment: The data logger was measuring liquid substances; to avoid the liquid from contacting any electrical circuit or the data logger itself, the liquid was moved further away from the data logger. Bunsen Burners/flammable liquids: The Bunsen Burner was used to test the fecal chloroforms, ethanol was applied to the glass of the agar plate to increase the heating process, to avoid any intensive ignition of flames.