Electrochemical Concentration and Purification of Spent Sodium Bicarbonate Blasting Media
Abstract
The feasibility and economics of recovering the spent blast media generated in sodium bicarbonate depainting operations has been investigated. In laboratory-scale tests, a saturated sodium bicarbonate solution was convened to sodium hydroxide in an electrochemical cell containing a Nafion cation exchange membrane. Energy consumption was 2 kWh per pound of sodium bicarbonate treated and could be reduced by a factor of two by operating the cell at higher flow rates. The proposed treatment train will essentially eliminate the need for off-site waste disposal, reducing the quantity of solid hazardous waste by over 99 percent and completely eliminating all liquid hazardous wastes. The capital costs of an electrochemical treatment system was estimated to be $19,400 for a plant sized to treat 25 lb/day blast media. Estimated operating costs amount to $2,270/yr, some 90 percent less than the $26,850/yr needed for makeup of the blast media and off-site waste disposal when treatment is not used. The savings of $24,580/yr correspond to a very short payback period of 0.8 years (9.5 months) for the capital cost. It was concluded that by conserving resources and eliminating off-site waste disposal, treating the spent blast media has the potential for significantly reducing the overall costs for depainting.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 21, 1995
- Accession Number
- ADA367104
Entities
People
- Harris Gold
- R. E. Hicks
- Rhonda D. Levy
Organizations
- naval air station