METAL FINISHING POLLUTION PREVENTION OPPORTUNITIES DEVELOPED THROUGH THE USE OF PLATO'S PROCESS PLANNER™

Pollution prevention alternatives were evaluated for a wide range of metal finishing operations at an aircraft overhaul and repair facility. A baseline model of the metal finishing operations for this shop was developed using PLATO'S PROCESS PLANNER™. This model estimates wastewater generated, sludge generated, electricity usage, and operating costs at facility, process-line, and process levels. Process activity-specific costs and quantities from the model help with the identification and prioritization of opportunities for process improvement with favorable payback potential. Metal finishing operations were evaluated to identify potential pollution prevention opportunities. Approximately 70 opportunities were identified initially. Through a screening and evaluation process, the list of opportunities was narrowed to 15. The top five were selected for implementation. This paper focuses on two of the alternatives selected for implementation.These two pollution prevention alternatives focus on chromium waste reduction. One project involves solution maintenance and rinse water return for the chrome anodizing process. The second project involves modifications to the fixtures and anodes for the hard chrome plating process. These two projects have a return on investment of 1 to 2 years as a result of chemical savings, waste reduction, and reduction in rectifier usage. These two alternatives will reduce the amount of chromium sent to the wastewater treatment plant (WWTP) by 40 percent or more, overall. In addition, the amount of sludge sent off site will be reduced by an estimated 35 percent (or approximately 70,000 pounds per year [lb/yr]).