Figure 1:
Photo of experimental setup showing PVC column, peristaltic pump, inflow reservoir and waste collection carboy. Aqueous-metal solution is pumped up through the column in order to displace all of the pore-space air and prevent short-circuit flow.
Samples were collected periodically (every 15 minutes for the first two hours of the experiment, every 30 minutes thereafter) at the outflow of the column in 50-mL graduated polypropylene tubes and capped. Effluent not sampled was collected in 5-gallon (18.9 L) plastic carboys and sent to a hazardous waste treatment facility. The aqueous-metal solution was prepared from the dry-standard compounds listed in Table 1. Samples were analyzed for aqueous-metal species using Acetylene-Air Flame/Atomic Adsorption (Perkin-Elmer Model 5100PC), using single-element hollow cathode lamps. Three-point standard curves were prepared from stock solution for each element. Check samples were used periodically throughout sample analysis to ensure quality control. Sample pH was measured using a calibrated Fisher-Scientific Model AR-20 pH meter and electrode.
Table 1. Stock compounds used for combined influent solution
Figure 2:
Oilsorb and Granular Activated Carbon
