D.3.3 Data presentation

24 hr at a rate of 40 revolutions per minute. Record the time tumbling

starts and stops.

h. Remove the centrifuge bottles from the tumbler and place paired bottles

opposite one another in a refrigerated centrifuge. Centrifuge stainless

steel tubes for organic contaminant analysis at 6,500 H g for 30 minutes.

Note: Stainless steel centrifuge tubes are heavy, limiting the speed of

centrifugation. Leachates for metals are centrifuged at 9,000 H g.

i. Assemble the decontaminated filtration apparatus. For organic

contaminants, the 4-micron prefilter is placed over the 1-micron glass

fiber filter. Filter the samples, maintaining a nitrogen atmosphere over

the samples while filtration is ongoing. Acidify leachate for organic

analysis with 1 mL of concentrated HCl per liter of leachate to prevent

iron precipitation and organic scavenging, then transfer sample to a

precleaned, 1-L amber glass bottle. Bottles for analysis of organic

contaminants should be filled to the top. For metals, much the same

procedure is followed. Filter the sample through a 0.45-micron filter and

acidify with 1 mL of concentrated Ultrex nitric acid per liter of leachate.

Transfer leachate samples to plastic bottles for storage and analysis.

j. In the deoxygenated glove box, record the weight of the centrifuge bottle

with lid and sediment after filtering. Repeat with remaining samples.

k. Add DDI water to the centrifuge tubes to bring them back to the same

water to solids ratio of 4:1. Record the weight of bottle with lid, DDI

water, and sediment. Repeat with remaining samples.

l. Tumble samples and centrifuge as described in steps g through i. Repeat

a minimum of four times.

m. Using DDI water, prepare and run a procedure blank according to the

procedure described above for one cycle.

n. Using DDI water, prepare a lab blank.

D.3.3 Data presentation

The data for each contaminant of concern should be presented in separate

tables that include the following information:

Leachate concentration for each leach cycle

Calculated sediment concentration (q) for each leach cycle where

qi =-qi-1 - 4Ci-1 and qo equals the initial sediment concentration

Contaminant distribution coefficient (Kd), which is the slope of the linear

regression of the leachate concentration for each leach, cycle, C, (x axis)

D12

Appendix D Leachate Testing Procedures