EV 311 Lab Manual |
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| Introduction | Assignments | Grading |
Performed with either a pH, salinity, conductivity meter or a dissolved oxygen meter:
The theory of pH measurement with a glass membrane electrode as well as a generic calibration procedure is described in your lab manual. Refer to the YSI meter operating instructions for directions specific to the meters. Alternatively, colored indicators or paper strips may be used. (internet tutorial;internet theory)
Many factors such as pH, conductivity and dissolved oxygen are temperature-dependent. Therefore, it is advisable to measure the temperature by placing the probe directly in the body of water to be measured. The DO and pH probes are both capable of temperature measurement. Though it is better to calibrate the pH meter at the temperature of the water being measured, we will use the automatic temperature compensation instead. (internet tutorial)
Conductivity is a measure of the concentration of dissolved ions in solution though the measurement depends on the types of ions as well as their concentration. The general theory of conductivity is described on pp. 42-43 of Kegley and Andrews. The generic field measurements are described on pp. 45-46. For more specific instructions, see the guide included with the YSI meters. Conductivity is typically measured in units of micoSiemen/cm. Parameters related to conductivity include total dissolved solids and salinity.
The parameters that affect DO include temperature, atmospheric pressure, salinity, mixing, biochemical oxygen demand (BOD) and chemical oxygen demand (COD). The use of a dissolved oxygen meter is described in detail on pp. 28-34. The saturated values of DO as a function of temperature are provided in table 3-1 on p. 38. A generic field method for dissolved oxygen is provided on p. 37. For more specific instructions, refer to the YSI DO meter instructions included with the meters. (web tutorial)
The definition of salinity is closely related to conductivity, but generally reserved for ocean or inland seas. The definition is given on p. 41 and p. 44. Salinity is normally measured in parts per thousand (ppt).
Flow (with meter)
Flow (with float)
Cation Analysis (Na, K, Mg, Ca, NH4) by Ion Chromatography
Read completely the chapter on ion chromatography (pp. 102-107) for analysis of cations, even though the chapter focuses on anions..
The theory of alkalinity is provided in your lab manual. We will use both the pH meter method and the colorimetric method for alkalinity determination. See the web tutorial for more information.
Total Dissolved and Suspended Solids
This is described on the web tutorial.
Biological Oxygen Demand (Winkler method) and Dissolved Oxygen
We will measure DO in the field with the YSI DO probes. The titrimetric procedure for BOD and dissolved oxygen analysis is described in detail in an EPA web tutorial,
Coliform Bacteria
The procedure and details of the test are described in an internet tutorial. The methods for calculating the MPN from teh Durham tibes and procedure are provided in the linked PDF document.
Macroinvertebrate Survey
An excellet online dicotomous key is provided by the University of Virginia website.
Last Updated April 13, 2005
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©copyright 2005 Colorado College Environmental Science Program
Heavy Metals (Cd, Pb, Cr, Cu, Fe, Mn, Ni, Zn, Si) Analysis by ICP
The technique of inductively coupled plasma spectrometry (ICP) will be explained briefly in class and used to determine trace levels of all the listed metals,
