Title: The relationship between the amount of soil and the turbidity of the water. Introduction:Turbidity is the technical term referring to the cloudiness of a solution and it is a qualitative characteristic which is imparted by solid particles obstructing the transmittance of light through a water sample (Turbidity). Turbidity often indicates the presence of dispersed and suspended solids like clay, organic matter, silt, algae and other microorganisms (Allot 203). The measurement of turbidity is an important test when trying to determine the quality of water.Organisms like phytoplankton can contribute to turbidity in open water (Holtzclaw 184). Erosion and effluent from highly urbanized zones contribute to the turbidity of waters in those areas. Construction, mining and agriculture, disturb the soil and can lead to raised levels of sediment which runoff into waterways during storms (Rutherford 48). Storm water from paved surfaces like roads, bridges and parking lots also contribute to turbidity (Rutherford 49).Nephelometric Turbidity Units (NTU) are the units of measurement used by a nephelometer meeting EPA design criteria (Turbidity). The amount of light scattered is influenced by many aspects of the particles like color, shape, and reflectivity. Because of this, and the fact heavier particles may settle quickly and may not contribute to the turbidity reading, the relationship between turbidity and total suspended solids (TSS) can change depending on the location that the test sample was collected (Turbidity).Research Question: To what extent does the amount of soil affect the turbidity of water?Hypothesis: If the soil content increases from 0.0g, 0.5g, 1.0g, 1.5,g and 2.0g then the turbidity of the water will increase as the soil content increases and will increase the most when the soil content is at 2.0 grams. Identification of variables: Independent Variable:UnitsRangeIndependent VariableSoil Amount Grams (g) 0g-2gSoil Amount 0g (control)0.5g 1.0g1.5g2gTrials55555Dependent Variable:UnitsRangeDependent VariableTurbidityNephelometric Turbidity Units (NTU)0.2 – 336.4Constants:Controlled VariableUnitsMethod of ControllingReason for ControllingTime Intervals for Data CollectionSeconds (s)Have the same amount of time intervals 0-60 sec. of for the reaction between rennet and milk to take place in each trialThe same time intervals for each trial will allow to compare each different solution Amount of Substance Milliliters(mL)Use the same amount of distilled water 100mlDifferent amount of each will result in different results thus altering the data and having inaccurate resultsSame type of soil–Use one brand of a specific soil.Use the same soil so the results are accurate and allows for the data to be analyzedProcedure:If your sample water is very clear, you might want to let the Turbidity Sensor warm up for about five minutes to assure a stable voltage. Calibrate the sensor by first obtaining the cuvette containing the Turbidity Standard (100 NTU) and gently invert it four times to mix in any particles that may have settled to the bottom. Wipe the outside of the cuvette with a soft, lint-free cloth or tissue. Holding the standard by the lid, place it in the Turbidity Sensor. Align the mark on the cuvette with the mark on the Turbidity Sensor. Close the lid. Enter 100 as the value in NTU. Remove the standard. Next prepare a blank by rinsing the empty cuvette with distilled water, then filling it to the top of the line with distilled water. Important: The bottom of the meniscus should be at the top of the line for every measurement throughout this test. This volume level is critical to obtain correct turbidity values. Screw the lid on the cuvette. Wipe the outside with a soft, lint-free cloth or tissue. Holding the cuvette by the lid, place it into the slot of the Turbidity Sensor. Make sure that the marks are aligned. Close the lid. Enter 0 as the value in NTU. You are now ready to collect turbidity data. Next, place a weight boat on the electronic balance and press the zero button. Now, using the scoopula, measure out 0.5 grams of soil.Obtain a cuvette and pour water until it has reached the line on the cuvette. Then, pour the 0.5 grams of soil into the cuvette.Gently invert the solution to mix in any particles that may have settled to the bottom. Screw the lid on the cuvette. Wipe the outside with a soft, lint-free cloth or tissue. Hold the cuvette by the lid and place it into the Turbidity Sensor. Make sure the marks are aligned. Close the lid. Monitor the turbidity value. Once it has stabilized record the results in a data table.Once data is collected, remove the cuvette and rinse it with distilled water. Repeat steps 13 to 17 to record 5 trials for each variation of the independent variable (0g, 1.0g, 1.5g, 2.0g ).After all data is collected rinse the cuvette with distilled water and dispose of all material accordingly.Risk Assessment:There were no immediate safety hazards when conducting this experiment although precaution can be taken when working with the soil and glassware. It is recommended to wear an apron and gloves to avoid the soil spilling on your clothes and any protect your hands from glassware incase it is broken. The soil pH is insignificant as the ph of the soil is roughly 7, which is neutral and innocuous. Data Collection and Processing:Method of Data Collection: Turbidity sensor connected to LabQuest and laptop. Electronic balance used to measure the amount of soil.Qualitative Data: Distilled water after having the turbidity measured. The water contain 0.5 grams of water making it murky.Table 1: The Relationship between Amount of Soil and Turbidity of WaterAmount of Soil (g)Turbidity (NTU)Trial 1Trial 2Trial 3Trial 4Trial 50.0g (control)0.60.40.50.40.20.5g75.264.371.873.973.61.0g118.6144.3133.4138.2131.41.5g216.6211.3215.6218.4213.22.0g336.4250.6280.6270.1286.3Processed Data:Mean: The mean of the turbidity of water with various amounts of soil was determined by adding all values and dividing the sum by the number of values. Worked Example:(0.6 + 0.4 + 0.5+ 0.4 + 0.2)/5= -.42Table 2: Average Turbidity of varying Soil AmountsAmount of Soil (g)Average Turbidity (NTU)00.420.571.761133.181.5215.022284.8Graph 1: The Average Turbidity for varying Soil AmountsAnalysis & Discussion:From my study, it is evident that there is a direct and a positive correlation between the amount of soil and the turbidity of water. The sample with 2.0 grams of soil contained the highest turbidity at an average of 284.8 NTU. The control shows a significantly lower turbidity as it did not contain any soil therefore, allowing the scattered light to pass through. The results completely agrees and confirms my hypothesis which stated that the increasing amount of soil will cause the turbidity to increase and that the highest turbidity would be found when the water contained 2.0 gram of soil. The data indicates an almost linear relationship between the soil content in water and the turbidity as when the soil amount was increased by 0.5 grams, the turbidity increased by roughly 70 – 80 NTU. This is due to how there is an increased amount of total suspended solids in the water causing the scattered light to bounce around and hit the detectors thus causing the turbidity to increase. The controI served as a good indicator for comparing the results, however, it was surprising that the distilled water did not contain a turbidity of 0 NTU. Distilled water is created through the process of distillation. The process of distillation is when the pure H2O is boiled out of its contaminants. So, many of the contaminants found in water are inorganic minerals, metals etc. Those types of contaminants have very high melting points and even higher boiling points. So, as the water with its contaminants is boiled, the pure water turns into steam and is captured and cooled and thus becomes distilled water. The junk left behind is all of the contaminants. Since all the contaminants are left behind one can assume there are no suspended solids in the water, however, very small particles were present causing the turbidity to be in between 0.2 – 0.6 NTU. The results indicate a rising problem in the environment. High turbidity levels can reduce the amount of light reaching lower depths in bodies of water like rivers, lakes and reservoirs, which inhibits growth of some forms of aquatic plants and can negatively affect species that are dependent on them, like fish and shellfish. High turbidity levels will also hinder a fish’s ability to absorb dissolved oxygen. This condition has been observed and documented throughout the Chesapeake Bay in the Mid-Atlantic region of the USA. ConclusionFrom my results I can conclude that there is a direct relationship between the amount of soil in the water and the turbidity of water. When the amount of soil increased, the amount of turbidity increased as well. The control contained the lowest amount of turbidity due to how there was no soil in the water therefore, allowing the scattered light to completely pass through and not reach the detectors. The highest amount of turbidity was found in the sample with 2.0g of soil in the water. This was due to how the soil caused a change in the composition of the water thus, causing the water to become more murky and increasing the turbidity as the scattered light reached the detectors. One thing this study has shown is that the amount of soil can affect the turbidity of water and can therefore have a significant effect on the environment but this is not necessarily only due to the amount of soil. It will also depend on many other components found in the water such as pollution and algae. While many factors affect the turbidity of water, soil content can be lowered by reducing the amount of human activity as construction, mining, and agriculture cause the soil sediments to flow through runoff. ApplicationTo solve the issue of the high turbidity of water due to the amount of soil, a reduction in human activity will be necessary in order to reduce the amount of sediments from flowing into the water. Human activities such as construction, mining, and agriculture disrupt the formation of the soil causing it to become more loose and sediments running off with the water. Storm water from paved surfaces like roads, bridges and parking lots also contribute to turbidity. Having campaigns, posters, and regulations that limit the amount of human activity can reduce the turbidity of water. This solution would improve all aquatic ecosystems as a lower turbidity allows more light to pass through, promoting the growth of aquatic plants and increasing the amount of dissolved oxygen found in the water. Evaluation: Some of the weaknesses throughout the experiment can mostly be due to uncertainties. The use of the electronic balance and turbidity sensors cause an uncertainty in the measurements of roughly plus or minus 0.05 for both instruments. The uncertainty may be significant but can affect the results of the data. Another weakness or limitation would be how the soil does not technically mimic the water in the environment. In the environment, there are many other factors involved in increasing the turbidity of water such as algae and pollution. Therefore, the conclusion that reducing the amount of soil in the water is not the only factor that needs to be considered. However, since it is one of the factors involved, more precaution can be taken to limit its effect on water. The type of soil can serve as a weakness because in reality the water will contain sediments of many substances and not just one type of soil thus these various factors affect the application of the experiment.