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SECTION NINE
SUMMARY AND CONCLUSIONS
The objective of this study was to evaluate the potential use of waste
foundry sand as an inexpensive medium for permeable reactive barriers (PRBs).
Batch and column tests were conducted to evaluate the reactivity and sorptive
capacity of twelve foundry sands for common groundwater contaminants. The
batch tests are conventional expedient tests conducted for design purposes. The
column tests more accurately simulate field conditions. Contaminants used in the
tests included TCE, the herbicides alachlor and metolachlor, and zinc.
Parameters obtained from these tests were then used to size PRBs for typical
field conditions.
Tests were also conducted to evaluate the leaching characteristics of
foundry sands. Batch water leach tests, column leach tests, and total elemental
analyses were conducted. The water leach tests and total elemental analyses
were conducted to categorize the foundry sands in accordance with Section NR
538 of the Wisconsin Administration Code. The column leach tests were
conducted to evaluate leaching that might occur under field conditions where
foundry sands are used as a PRB medium.
The following sections summarize the findings of the tests conducted for
each contaminant that was considered, and the results of the leaching tests.