PREPRODUCTION INITIATIVE-NELP BLAST MEDIA SEPARATOR FINAL REPORT NS MAYPORT, FL

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1 1.0 INTRODUCTION PREPRODUCTION INITIATIVE-NELP BLAST MEDIA SEPARATOR FINAL REPORT NS MAYPORT, FL The U.S. Navy has adopted a proactive and progressive position toward protecting the environment and complying with environmental laws and regulations. Rather than merely controlling and treating hazardous waste by end-of-the-pipe measures, the Navy has instituted a program for pollution prevention (P2) to reduce or eliminate the volume and toxicity of waste, air emissions, and effluent discharges. P2 allows the Navy to meet or exceed current and future regulatory mandates and to achieve Navy-established goals for reducing hazardous waste generation and toxic chemical usage. P2 measures are implemented in a manner that maintains Navy readiness. An additional benefit has been a general increase in operational efficiency and worker safety. The Navy has truly set the standard for the procurement and implementation of P2 equipment. The Chief of Naval Operations (CNO), Environmental Protection, Safety, and Occupational Health Division (N45), established the Pollution Prevention Equipment Program (PPEP), through which both the Naval Air Warfare Center Aircraft Division Lakehurst (NAWCADLKE) and the Naval Facilities Engineering Service Center (NFESC) serve as procurement agents under the direction of N45. P2 equipment is specified and procured under two complementary initiatives the Preproduction Initiative (i.e., technology demonstration) and the Competitive Procurement Initiative. The Preproduction Initiative directly supports both the Navy Environmental Leadership Program (NELP) for P2 shore applications and the P2 Afloat program, which prototypes and procures P2 equipment specific to the needs of ships. This report provides an analysis of the procurement, installation, and operation of P2 equipment under the Preproduction Initiative. Technology demonstrations and evaluations are primarily performed under NELP at two designated NELP sites Naval Air Station (NAS) North Island and Naval Station (NS) Mayport. Additional sites have been added as required to meet mission goals. The program involves defining requirements, performing site surveys, procuring and installing equipment, training operators, and collecting data during an operational test period. The equipment is assessed for environmental benefits, labor and cost savings, and ability to interface with site operations.

2 2.0 BACKGROUND The Blast Media Separator was proposed as a technology demonstration project under the PPEP. Although this particular demonstration was discontinued, the experience and insight gained should prove helpful if this concept is considered again. This report is intended to provide information that is general to the technology and specific to the site application. Used in conjunction with a blast booth, the unit could be used to separate water-soluble blast media from hazardous paint waste by dissolving the blast media. The resulting water-media slurry would then be released to the sanitary sewer. It is possible that heavy metals could leach out of the paint chips when the media was solubilized. Therefore, the filtration process must be able to contend with these potential contaminants to ensure that the effluent is acceptable for the local POTW. The planned test site was the walk-in multimedia blast booth area at SIMA NS Mayport. The blast booth removes paint from fiberglass and aluminum substrates (e.g., life raft canisters, antennae). It was expected that the separator unit would enhance the environmental benefits of the booth by reducing the volume of waste to be disposed of. Two types of water-soluble blast media sodium bicarbonate and Polymedia Lite (PML) were tested during the prototype period for the Walk-in Multimedia Blast Booth and were considered candidate media for the blast media separator. Although both of these media can remove paint from fiberglass substrates, are soluble in water, and can be dissolved in order to filter paint waste from mixed waste slurry, several differences should be noted. Sodium Bicarbonate Advantages: The water/sodium bicarbonate slurry could possibly be reused for cleaning purposes. The media itself is non-hazardous. 1 The cost is $0.83 per pound of fresh blast media. Disadvantages: Only one useful cycle per given batch of media used. Copious amounts of water required for dissolution. Polymedia Lite (PML) Advantages: Six to eight useful cycles per given amount of media. 1 Although specifically formulated for use on fiberglass substrates, the abrasive present in the media is simply a larger particle size of sodium bicarbonate. This means only treatment of the paint waste (and any heavy metal leachate) would be required.

3 Compared to sodium bicarbonate, the waste requires less water for dissolution. PML is composed mostly of starch a non-hazardous material. Can be broken down to carbonaceous residue through the metabolic pathways of microorganisms. The option exists to lease or buy. 2 It costs $2.25 to buy a pound of fresh blast media and $2.75 to lease a pound of fresh blast media. Disadvantages: Contains trace amounts of Methyl Methacrylate Monomer a hazardous material. Waste slurry cannot be reused. Both media were to be tested in the blasting operation to determine their efficiency, effectiveness, and environmental savings. Cost/benefit analyses and performance data would then be reviewed to determine the best media for use in the booth. Alternatives to be considered included the following. 1. Buy sodium bicarbonate and treat in the blast media separator with possible reuse of slurry. 2. Buy PML and treat in the blast media separator unit. 3. Lease PML and return the waste to the vendor for off-site treatment. 3.0 EQUIPMENT DESCRIPTION 3.1 Vendor Selection Several technologies were considered from electrostatic separation to gravity settling to separation by density and wet separation. Wet separation was determined to be the most reliable method because the paint chips were nearly the same size and density as the media itself. Hydro Engineering s Low Solids Solubalizer, CMAFU, and ACF3 equipment were selected because this system was the most cost-effective and the least labor-intensive unit of those considered. 3.2 Specifications The composition of the system s effluent determines compliance with local limits. This variable fluctuates as the concentration of contaminants in the influent changes. (The contaminant concentration of the influent changes according to the blasting media used and the substrate being blasted.) It is necessary to determine the contaminant levels expected and the limits accepted by the local POTW and to treat the effluent at the most conservative levels (i.e., treat as if all contaminants are present at all times). 2 If buying, the media would be handled by the separator unit and released to the POTW. If leasing, the separator unit would be unnecessary, and the used media would be returned to the manufacturer for reconditioning.

4 3.2.1 Treatment Process Dry media and paint waste gravity settle into the 3 gpm Low Solids Solubalizer. Water is then added to the dry media-paint chip mixture. Once the solubalizer has dissolved the media, the slurry flows into the basic separator unit. The basic separator unit the Hydro CMAFU uses a paper filter to separate the paint chips from the water-media slurry down to 5 microns at a maximum flow rate of 20 gpm. This paper filter automatically advances from a supply roll according to the pressure differential. This differential indicates when the filter has reached capacity. (If a continuous flow design is chosen, the limiting factor on flow rate through the system would be the 3 gpm solubalizer.) To ensure compliance with local levels, the Hydro Model ACF3 equipment was considered as a polishing stage and would have been an addition to the basic separation unit. The ACF3 consists of an ozone generator and an activated carbon filter, which removes light hydrocarbons and metals. This process achieves filtration down to one micron at a maximum flow rate of 12 gpm. Because dilution is not an acceptable treatment, an important consideration is not to lower toxicity concentration by adding more water than is needed to dissolve the blast media. The solubility of sodium bicarbonate in water is 8.6 g/ F, and the solubility of PML in water is 90%, as stated in the MSDS Volume The expected volume of dry media contaminated with paint waste was approximately gallon drums per month (i.e., 4,000 pounds per month) when using either sodium bicarbonate or PML blast media. At NS Mayport, blasting occurs regularly with minor changes in frequency according to workflow. Because the separator system should be sized to handle larger volumes, the solubalizer should have at least a minor degree of excess capacity. With these volume parameters as a guideline, the separator system could be designed either for batch or continuous flow Dimensions The dimensions of the dust collector under which the solubalizer was to be placed are approximately 100" x 73". Clearance under the crossbars is approximately 40" at the lowest point. Currently, a 55-gallon drum is placed under the dust collector for waste collection. The 3 gpm Low Solids Solubalizer has dimensions of 60" long x 30" wide x 39" high. The CMAFU has dimensions of 70" long x 29" wide x 44" high; the ACF3 dimensions are 120" long x 34" wide x 77" high. 3.3 Implementation Requirements Installation requirements include: Water Supply: For dissolution of the media in the solubalizer

5 Drain Access: Water will be discharged from the CMAFU or ACF3. Electric: 115 volts, 15 amps for CMAFU; 230 volts, 20 to 30 amps for ACF3 Weather Protection: None required 3.4 Benefits The expected benefits of the blast media separator are: reduce volume of hazardous waste reduce hazardous waste disposal costs. By separating non-hazardous blast media waste from the hazardous paint waste, the volume of hazardous waste would decrease substantially, and the non-hazardous waste could be treated by the POTW for safe release to the environment. 4.0 DATA ANALYSIS 4.1 Vendor Test Results Vendor testing determined whether sodium bicarbonate and PML could be effectively treated in the Hydro Engineering wet separation process. Samples were taken of both virgin media and the spent media-paint waste mixture for sodium bicarbonate and PML. These samples were sent to Hydro Engineering to verify the equipment s ability to achieve satisfactory separation. Although the Hydro Engineering unit could handle separation of sodium bicarbonate blast media, PML could not be effectively treated using wet separation techniques. Once dissolved, approximately 20% passed through the filter, and 80% settled out and coagulated onto the paper. This translates to large volumes of waste to be disposed of and additional water weight. Therefore, dry disposal was recommended for PML. 4.2 Choice of Media During the blast booth technology demonstration, NS Mayport determined that sodium bicarbonate was not the optimal choice for a blast media due to: 1. the aggressiveness of the stripping, which resulted in pitting of the substrate 2. the fine particle size of the blast media, which required a longer loading time 3. the need for more media (compared to the PML) because sodium bicarbonate can only be cycled once. Therefore, it was determined that NS Mayport would discontinue use of sodium bicarbonate in the Walk-in Multimedia Blast Booth.

6 4.3 Quantitative Analysis No quantitative analysis is available regarding cost savings or environmental benefits because PML was determined to be incompatible with the separation equipment and the site decided not to continue using sodium bicarbonate blast media. 4.4 Qualitative Analysis Installation The unit was never installed Training No training was provided because the unit was not purchased for the site Maintainability Maintainability was not established because the unit was not tested in an operational environment Interface with Site Operations Interface with existing site operations was the biggest obstacle in this demonstration because the choice of media from the blasting operations was not compatible with the separator unit Overall Performance The blast media separator was never purchased and, therefore, was never tested at the site. However, based on vendor test analyses, the unit worked well for sodium bicarbonate blast media but not for PML. 5.0 LESSONS LEARNED During the preliminary vendor tests focusing on system requirements, it was determined that wet separation of PML from paint waste was not viable. However, the system worked well for sodium bicarbonate separation and should be considered in the future if a sufficient volume of sodium bicarbonate blast media is used. 6.0 CONCLUSIONS Once the use of sodium bicarbonate was discontinued at NS Mayport and because PML was not compatible with the Blast Media Separator, a message was released to the fleet inquiring about the use of sodium bicarbonate blast media at other sites so that the separator could be prototyped elsewhere. Due to a low number of responses to the message, the prototype was discontinued. NS Mayport subsequently arranged to lease PML instead of paying outright for disposal.