Potential Use of Reverse Osmosis in Managing Saltwater Waste Collected at Road-salt Storage Facilities

About the report:

The implementation of its anti-icing program comprises a large part of the Virginia Department of Transportation's (VDOT) maintenance effort. Earlier research confirmed that VDOT captures a large volume of salt-laden stormwater runoff at its 300+ salt storage facilities throughout the state and that the disposal options for this water are limited and costly. Although VDOT is implementing recommended management options to reduce the quantity of saltwater captured, this research was undertaken to determine if the use of reverse osmosis (RO) is a feasible method of treating the captured water. Field and laboratory tests were conducted using RO to treat stormwater containing high levels of NaCl. The results of these tests suggest that RO is a feasible method to reduce the levels of Cl to less than 250 mg/L for nearly all initial levels of NaCl found in VDOT's stormwater ponds. However, the RO system tested would not be capable of reducing Cl levels to 25 mg/L for all NaCl concentrations found throughout the state. Overall, although RO proved to be quite successful at reducing the levels of Cl, pretreating the stormwater to reduce the turbidity levels of the runoff water before it entered the RO system was very difficult, but achievable.

Authors