| The USEPA is expected to set a new drinking water MCL for arsenic in the range of 2--20 mug/L. Therefore, many treatment facilities will need a simple, cost efficient, reliable method to remove arsenic.; This research involved column experiments to evaluate the sulfur modified iron (SMI) process for the removal of arsenic from drinking water. The SMI process uses granular iron and elemental sulfur for arsenic removal. Experiments show that SMI is able to remove both As(V) and As(III) to levels <5 mug/L for a limited time. Flow occlusion from rusting/bridging limited column lifetimes. Addition of sulfur (>100:1, Fe:S) increased run life and arsenic removal. An 8&inches; column run provided arsenic removal for 7 days (<5 mug/L) at 0.5 gpm. Oxygen was shown to be important in arsenic removal. Many problems were encountered which will need to resolved before this process can be considered viable. |
