The overall objective of the validation study was to confirm that the ENVIRO-CLEAN PROCESS would remove mercury from an utility waste sample to very low levels (
Test Procedures
Approximately five (5) gallons of mercury waste was received at Lewis’ facility on August 15, 1994. The waste sample was opaque/white in color. A portion of the feed sample was collected and submitted for analysis; the analysis is presented in Table 1. The balance of the mercury waste was processed through the ENVIRO-CLEAN PROCESS pilot carbon unit. The system consisted of a feed pump, pH controller and two (2) carbon columns. Each column contained about 180 grams of proprietarily pretreated granular activated carbon. The flowrate was set at 20 ml/min with the feed solution pH controlled at 4.5. Effluent samples were collected and analyzed for total mercury. The feed and effluent analysis are presented in Table 1, with the time periods, designating when the sample was collected during the test run.
TABLE 1. ENVIRO-CLEAN EFFLUENT ANALYSIS
| Sample | Mercury (µg/l) |
|---|---|
| Feed | 124,100 |
| Sample #1 (2 hrs) | <5 |
| Sample #2 (4 hrs) | <5 |
| Sample #3 (6 hrs) | <5 |
| Sample #4 (8 hrs) | <5 |
| Sample #5 (10 hrs) | <5 |
The processing of the mercury sample was completed without any mechanical or process difficulties. The effluent was crystal clear with no visible trace of solids or color. The activated carbon system removed over 99.9% of the mercury from the waste sample.
summary
The ENVIRO-CLEAN PROCESS produced a low level mercury effluent. The system was effective in removing mercury with removal levels exceeding 99.9%. The feed contained 124,100 µg/l of mercury. The average mercury concentration in the effluent was