II. METHODOLOGY

The following treatment steps were performed, prior running the impacted water through to column filtration:

Filter media to be tested:

A – ChemSorb PRB
B – ChemSorb KL
C – ChemSorb FS
D – ChemSorb MK
E – ChemSorb ML

STEP 1: Filtration of raw impacted groundwater on 4-microns filter

STEP 2: Column filtration with the 5 selected media. (See pictures 1-4 of the lab set up below)

A-ChemSorb PRB — Empty Bed Contact Time (EBCT):16 minutes
B- ChemSorb KL — EBCT: 8 minutes
C- ChemSorb FS — EBCT: 8 minutes
D- ChemSorb MK — EBCT: 8 minutes
E- ChemSorb ML — EBCT: 16 minutes

STEP 3: After each calculated EBCT, an eluted water sample was taken and then the sent for analysis to an external independent laboratory.

III. RESULTS AND DISCUSSION

According to the results shown in Table I, it appears that three media were able to reach the rejection criterion set at 0.0013 μg/L: ChemSorb FS (0.0013 μg/L), ChemSorb MK (less than 0.0010 μg/L) and ChemSorb ML (less than 0.0010 μg/L), with respective removal rates of 73%, 100% and 100%. The latter two reaching the lab detection limit.

Table I- Results of mercury treatment

Table II – Impact of the filtration metal on the other metals present in the submitted sample

IV. RECOMMENDATIONS

Taking into consideration the mercury removal rate and the dosage of the media used, the recommended media is ChemSorb ML. According to the test results obtained, this media was effective at a retention time: 16 minutes. This performance is followed by ChemSorb MK at a retention time: 8 minutes.

Customer has elected to select the ChemSorb MK to cope with the filtration of their mercury impacted GW. 10 m3 of media were used to load up the vessel for this new treatment start up.