Environmental Engineering Reference
In-Depth Information
Field Exercises
Field Exercise 1: Use and Interpretation of IRIS Tubes
Objectives
1. To understand the principles behind the use of IRIS tubes.
2. To understand how to use IRIS tubes in the field.
3. To understand how to interpret the data from IRIS tubes.
4. To compare the functioning of IRIS tubes with other measures of reduction in soils.
Part I: IRIS Tube Installation
Materials and Equipment Needed
Five IRIS tubes
7/8
00
push probe for making pilot holes
Spade or shovel
Tape measure
Transparent mylar grids
Equipment for making Eh measurements
Five, 40 cm Pt wire electrodes
One reference electrode (with salt bridge)
One, high impedance voltmeter
pH meter and buffers (This can be done in the field using a portable meter, or else
samples can be returned to the lab for pH measurement.)
Alpha, alpha dipyridyl dye solution or test strips
Procedures
Overview
: IRIS tubes will be installed following protocols spelled out in the
Rabenhorst (
2008
) article. Tubes will remain in the soil for 4 weeks, after which
they will be examined and paint removal will be quantified. On the dates on which
the tubes are installed and extracted, water table levels will be documented. Also on
these dates, soil reduction will be assessed using Eh (and pH) measurements and
also by testing with alpha, alpha dipyridyl dye. Comparisons will be made among
all three methods for assessing soil reduction.
1. Students should work in teams of 3-4 persons.
2. Each team will install a set of five IRIS tubes in the field (at a site provided by the
instructor), following protocols spelled out in the Rabenhorst (
2008
) article.
