Engineering Services

The vast majority of work performed by CAI Engineering involves the metal finishing industry; either directly with industrial companies, as a subcontractor on large-scale design and construction efforts, or as a technical resource to EPA, the military, or other government entities. CAI is perhaps most frequently recognized by our work performed with the National Center for Manufacturing Sciences, including the NCMS/NAMF P2 project and the establishment of the National Metal Finishing Resource Center. Our expertise includes most plating processes, painting, maching, printed wiring board manufacturing, chemical solution maintenance technologies, chemical recovery technologies, and wastewater treatment.

Project Experience

Pollution Prevention and Control Technology Survey

CAI Engineering conducted an extensive project for the National Center for Manufacturing Sciences (NCMS) that assessed the pollution prevention and control technology available for electroplating firms The NCMS steering Group for the project was made up of representatives from the NCMS, National Association of Metal Finishers (NAMF), American Electroplaters and Surface Finishers (AESF) GM Allison Gas Turbine, Pratt & Whitney, and Texas Instruments.

The project collected data by employing three methods: (1) a 20 page questionnaire sent to 1,200 plating companies; (2) a vendor survey of 100 manufacturers/vendors of plating and pollution control equipment; and (3) an extensive literature search covering the Defense Technical Information System (DTIC), Dialog, EPA's Pollution Prevention Information System, American Defense Preparedness Association, trade associations, conference proceedings, technical journals and reports. The information and data from these three sources were entered into a relational database designed and operated by CAI.

The initial products of the project were made available in March, 1994. These products include an extensive report (hard bound book) that presents the results of the surveys and literature review and an electronic database (disk format). The results show which treatment, recovery and bath maintenance technologies have been most successful for different plating processes and the costs for purchasing and operating these technologies. The technologies covered by the project include, among others: ion exchange, reverse osmosis, electrowinning, evaporation, electrodialysis, diffusion dialysis, substitute plating processes, off-site recycling and end-of-pipe treatment. For each technology, information and data that are presented includes: technical descriptions; applications; restrictions; capital and operating costs; residuals generation; list of vendors; performance; effectiveness; and operational/maintenance problems for specific equipment models. The project results also cover trends in chemical substitution, the identification of compliance-problem pollutants, sludge generation rates, off-site sludge recovery and disposal options, and many other pertinent topics.

Joint EPA/industry Design for the Environment (DfE) project

This project involved a survey of the U.S. printed circuit board industry. The pollution prevention and control survey was performed to gather and organize information about the current state of environmental technology and practices for this industry segment. The focus of the survey was on determining the types of technologies and alternative processes used, the extent of their use, key factors with regard to implementation, including costs, and their success and failure rate. This project has been extended to include a survey of equipment suppliers. A final report is scheduled for June, 1997.

Waste Minimization Audits in Fes, Morocco

This project involved conducted environmental audits of metal finishing facilities in Fes, Morocco. This work was performed under the Project in Development and the Environment (PRIDE) in cooperation with the World Bank, Societe des Eaux de Marseills, USAID, and other international organizations. Various lo-cost P2 options were identified and evaluated. A final report was prepared (French only).

Reduction of Alodine Wastes and Other Aluminum Finishing Wastes, Martin Marietta Aerospace, Denver, CO

This project was conducted by CH2M HILL with the assistance of CAI Engineering as part of a major contract to develop compliance strategies for meeting stringent water quality effluent limitations. The objective of the project was to reduce the wastewater and hazardous waste discharges from Martin Marietta's aluminum finishing operations. These processes are used to treat large aluminum parts and missile subassemblies for the Titan Missile. Two key processes used at this site are Alodine and Iridite conversion coating. These chemicals are applied by both spray and dip tank methods. The resulting rinse water, that was contaminated with chromium, was being discharged to the treatment plant and presented compliance problems. The project focused on the design of a closed loop rinse system that could capture and separate the chromium and convert it to a reusable form. The design included ion exchange, electrodialysis and evaporation technologies. The system was procured by Martin Marietta.

The project also included an assessment of production rates, process chemistry, waste characterization, and regulatory constraints.

Implementation of Electrodialysis Bath Maintenance for Chromic Acid, McClellan AFB (243 G-BAY)

This project is being conducted by CH2M HILL with the assistance of CAI Engineering. The objective of the project is investigate, procure, test and implement the electrodialysis technology (i.e., membrane electrolysis) for hard chrome plating bath maintenance at McClellan AFB. Chrome plating baths at McClellan AFB, like other chromic acid solutions, build up inorganic contamination and must be periodically discarded to remain within operational limits. Electrodialysis is the most advanced method for chromic acid bath purification. The project has also investigated the use of the same technology for purification of Alodine and other acid solutions used at McClellan AFB. The procured electrodialysis unit will initially be used in the existing plating shop and latter will be used in the renovated facility. This project has investigated and evaluated the various commercial systems available for this application. Based on cost and technical performance data, a system has been selected. Work is now proceeding with a detailed design and procurement and installation will be completed within approximately four months.

Waste Minimization, General Dynamics

Two projects were performed at the manufacturing site for the Phalanx Missile under subcontract to CH2M HILL. The objective of the first project was to develop a process design that would meet stringent wastewater discharge standards, reduce water use or recycle water. Project procedures included a detailed review of an existing data base for process baths and wastewater, additional data collection, and technology evaluation/selection. The process design included reverse osmosis (40 gpm) for water recycle. The second project focused on identifying manufacturing process changes and recycle technologies to minimize the generation of spent process solutions and wastewater treatment sludges. A process design was prepared by CAI and later implemented. The system includes an ion exchange/electrodialysis/electrowinning system for closed loop electroplating processes, and various process and rinsing changes. One of the major waste streams included in the second project was generated from a chromate conversion process (Iridite).

Waste Minimization Study, Kennedy Space Center

The purpose of this project was to evaluate the technical and economic feasibility of implementing waste minimization and treatment technologies applicable to operations at KSC that generate hazardous waste and wastewaters. The target wastes include: acids, alkaline solutions, photo processing solutions, spent solvents and oils, paint and related products, machining fluids, fuels, battery fluids, and Alodine solutions. The waste minimization alternatives evaluation focused on process substitution, source control, recovery and reuse, as well as alternatives for treating the wastes remaining after the application of waste minimization technologies. The focuses of CAI's assignment were the processes and wastes associated with the refurbishment of the shuttle's used solid rocket boosters. The operation was surveyed from the point of unloading the retrieved boosters at the Cape Canaveral dock to final painting before reuse. As part of this project, a process design was prepared for recycling rinse water from an Alodine spray operation. The Alodine was sprayed onto segments of the solid rocket boosters, during reconditioning. The rinse water entered drains and was stored in a sump prior to off-site disposal. The closed-loop design permitted recycling of the rinse water and minimized the amount of waste hauled off-site.

Waste Minimization, Tinker AFB

This project was a cooperative EPA/Air Force effort that investigated the implementation of brush plating as a substitute coating for (1) hard chromium plating and (2) nickel sulfamate for selected aircraft engine parts. During this project, alternative brush plated coatings were identified and a test plan was developed to evaluate the mechanical and metallurgical properties of the coatings. The selected substitute coatings for hard chromium included hard nickel, nickel tungsten and nickel cobalt. The testing was performed on manufactured test specimens and included: adhesion, hardness, fatigue, and tensile strength tests. A demonstration brush plating line was specified and procured for plating the test specimens. The line will be subsequently used for production.

Plating Shop Upgrade and Modernization Program, Corpus Christi Army Depot

The objective of this project was to develop short term repairs and long term modernization plans for the plating shop at Corpus Christi Army Depot (CCAD). This facility supports the Army's only aeronautical facility for depot-level maintenance. It is responsible for the overhaul of the CH-47, UH-1, UH-60, AH-1, OH-58 and other helicopters. Approximately 25 different metal finishing processes are employed at the shop including electroplating, electroless plating, and aluminum finishing. The short term repairs focused on improving the safety of workers and meeting current wastewater and hazardous waste regulations. The long term plans include a conceptual design for a new plating shop. The new design, which has received congressional funding incorporates a low-discharge plating technology design through source control. Final design of the new shop is scheduled for FY 93.

Plating Shop Renovation Conceptual Design, McClellan AFB

This project was performed by CAI with the assistance of CH2M HILL. The purpose of the project was to develop a conceptual design for renovating the plating shop in 243-G Bay. CAI's participation in the project included: identification of metal finishing processes and bath chemistry for the renovated facility, development of alternative tank layouts, identification of pollution prevention and control methods for reducing waste generation, identification of recycling technologies, and identification of bath maintenance and control technologies and methods.

Waste Minimization, Lockheed Aeronautical Systems Company

This site is the manufacturing location for the C-130 and was selected for manufacturing the new advanced tactical fighter (F-22). As a subcontractor to Ebasco Corp., CAI was responsible for surveying industrial operations (waste audit) and developing waste minimization alternatives for metal finishing and machining processes. The metal finishing lines are primarily used for aluminum finishing and include anodizing and conversion coating (Alodine). During the project, CAI investigated production and chemical usage rates and performed a waste characterization. Using these data, a material balance was prepared that was employed to evaluate the impact of waste minimization options. Process designs were prepared and capital and operating costs were identified for closed loop recycling options for chromium bearing rinse waters.

Hard Chromium Plating, U.S. Mint

The U.S. Mint in Philadelphia installed a hard chrome plating system in 1989 for plating of coin dies. The system was only partially operational due to design problems. The objective of this project was to evaluate the system and prepare recommendations for improvement. The recommendations included: redesign of plating racks, changes to the rinsing configuration, improvements to the chrome rinse water closed-loop recycle system and changes to the system chemistry. The project also included the development of alternative methods for fume scrubbing.

Waste Minimization, Army Material Command

The purpose of this project was to conduct waste minimization surveys at selected Army Materiel Command (AMC) facilities and develop a strategy for reducing waste generation. The surveys focused on the industrial operations and the industrial wastewater treatment plants (IWTPs). Various methodologies and technologies for waste control were recommended and later implemented by the facilities.

Recovery of Spent Citric Acid Wastewater, Norfold Naval Shipyard

The objective of the project was to pilot test methods for the treatment and recovery of spent citric acid wastewaters generated during bilge cleaning. Testing was performed at the Norfolk Naval Shipyard. The testing focused on two technologies: ion exchange and an electrodialytic unit. This project provided the groundwork for subsequent research performed by the Navy.

Implementation of Electrowinning Technology at Navy Plating Shops, Naval Facilities Engineering Service Center

CAI Engineering completed a series of three projects that involved the installation, testing and evaluation of electrowinning units. The projects were performed at the Norfolk Naval Shipyard, Naval Air Warfare Center (Indianapolis, IN), and Cherry Point (NC) NADEP. The electrowinning units were installed on various production lines, including copper cyanide, copper sulfate, tin-lead, silver cyanide, and electroless nickel. Each test lasted for a period of one month. Daily sampling was conducted to determine the efficiency of the processes. Production and cost data were collected to determine the cost effectiveness of the technology. At the completion of each test, Navy platers were given O&M training and the units were placed into permanent operation.

Pollution Prevention Assessment, NADEP North Island Plating Shop, Naval Facilities Engineering Service Center

This project involved an engineering study to identify and evaluate metal finishing bath maintenance and chemical recovery methods for NADEP North Island (CA). The study included both conventional emerging technologies and approaches. Several years of data were collected and analyzed. Also NFESC conducted sampling of the process solution over a six month time period in order to track the contamination of baths. The major recommendation developed during the project was to implement a system of advanced portable bath maintenance technologies, including microfiltration, membrane electrolysis and ion transfer.

Treatment of Cooling Tower Blowdown From a Hazardous Waste Incineration Facility

The purpose of this project is to prepare a process design for a waste treatment/water recycle system for a 1,000 gpm cooling tower blowdown from a hazardous waste incinerator. Presently the system employees conventional treatment and discharges to a receiving stream. Due to pending, more stringent regulations, the client needs to further reduce the concentration of metals in the stream or to completely recycle the water. Preliminary designs have been prepared for reverse osmosis, electrodialysis and evaporator based systems. Pilot testing will be conducted in late 1994.

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