Lab Report

Tyndall Effect: Using Light to Look for Particles in Drinking Water

Answer the following questions about the results of this activity. Record your answers in the boxes.

Send your completed lab report to your instructor. Don’t forget to save your lab report to your computer!

Activity 1

Record your data from Activity 1 in the boxes below. Place the turbidity values for the Low and High standards in the appropriate columns. Then calculate and record the average of each of the three data readings for the Low Calibration and High Calibration Standards.

Standard / Low / High
Turbidity
Value 1
Turbidity
Value 2
Turbidity
Value 3
Turbidity
Value Average
Expected
Value
  1. Is the turbidity spectrometer accurate enough for this study? Explain why or why not.

  1. Is the turbidity spectrometer consistent enough for this study? Explain why or why not.

  1. What is the relationship between the appearance of the sample and the NTU value?

Activity 2

Record your data from Activity 1 in the boxes below. Place the data (turbidity value, appearance) for the samples in the appropriate columns (clean standard, maximum load, standard, sample 1, sample 2, sample 3)

The following information will be needed to make your conclusion --

In the region of the United States you are investigating, the allowable standards of turbidity are:

  • Drinking water is 0.3 NTU
  • Water for irrigation and industrial use 5 NTU
  • Water released into lakes is 10.0 NTU
  • Water released into rivers 15.0 NTU

Sample / Clean Standard / Maximum Load Standard / Sample 1 / Sample 2 / Sample 3
Turbidity Value
Appearance
(pictures from computer readout)
  1. Is the turbidity spectrometer accurate based on the data from the Clean Water and Maximum Load Water Standards?
Explain why or why not.

  1. Is the relationship between the appearance of the sampleand the NTU value of each sample consistent for all samples?
Explain why or why not.

  1. For each sample, make a recommendation for the best way to release or use the waste water based on the Turbidity Stands Chart.

  1. Research and describe the types of particles that scatter light in water and contribute to bad water quality. Go to the following Environmental Protection Agency Link as a reference: