In 1994, 50 facilities with SIC Code 35 ("Industrial Machinery and Equipment") or SIC Code 36 ("Electronic & Other Electronic Equipment") submitted a New Jersey Release and Pollution Prevention Report to the NJDEP describing their use of hazardous chemicals in 1993. Since plants with SIC Code 35 or 36 are considered Group Two facilities by the NJDEP, they were required to prepare a Pollution Prevention Plan and submit a Pollution Summary by July 1, 1996. As part of the preparation of a Pollution Prevention Plan, facilities are asked to find and analyze pollution prevention options and set reduction goals for hazardous chemical nonproduct output (NPO) and use.

The following pages list some pollution prevention techniques compiled by the United States Environmental Protection Agency (USEPA) that SIC Code 35 and 36 facilities may find useful to help set (and eventually meet) hazardous chemical NPO and use reduction goals.

ELECTROPLATING OPERATIONS

• Modify rinsing methods to control drag-out by:
  1. Increasing bath temperature
  2. Decreasing withdrawal rate of parts from plating bath
  3. Increasing drip time over solution tanks; racking parts to avoid cupping solution within part cavities
  4. Shaking, vibrating, or passing the parts through an air knife, angling drain boards between tanks
  5. Using wetting agents to decrease surface tension in tank.
• Utilize water conservation methods including:
  1. Flow restrictors on flowing rinses
  2. Counter current rinsing systems
  3. Fog or spray rinsing
  4. Reactive rinsing
  5. Purified or softened water
  6. Dead rinses
  7. Conductivity controllers
  8. Agitation to assure adequate rinsing and homogeneity in rinse tank
  9. Flow control valves
• Use drip bars to reduce drag-out.
• Use drain boards between tanks to reduce generations of drag-out.
• Install racking to reduce generations of drag-out.
• Employ drag-out recovery tanks to reduce generations of drag-out.
• Redesign rinse tank to reduce water conservation.
• Regenerate plating bath by activated carbon filtration to remove built up organic contaminants.
• Install pH controller to reduce the alkaline and acid concentrations in tanks.
• Install atmospheric evaporator to reduce metal concentrations.
• Install process (e.g., CALFRAN) to reduce pressure to vaporize water at cooler temperatures and recycle water by condensing the vapors in another container, thus concentrating and precipitating solutes out.
• Improve control of water level in rinse tanks, improve sludge separation, and enhance recycling of supernatant to the process by aerating the sludge.
• Install system (e.g., Low Solids Fluxer) that applies flux to printed wiring boards, leaving little residue and eliminating the need for cleaning chlorofluorocarbons (CFCs).
• Install ion exchange system to reduce generation of drag-out.
• Employ reverse osmosis system to reduce generation of drag-out.
• Use electrolytic metal recovery to reduce generation of drag-out.
• Utilize electrodialysis to reduce generation of drag-out.
• Implement evaporative recovery to reduce generation of drag-out.
• Implement the electrodialysis reversal process for metal salts in wastewater.
• Substitute cyanide plating solutions with alkaline zinc, acid zinc, acid sulfate copper, pyrophosphate copper, alkaline copper, copper fluouborate, electroless nickel, ammonium silver, halide silver, methanesulfonate-potassium iodide silver, amino or thio complex silver, no free cyanide silver, cadmium chloride, cadmium sulfate, cadmium fluouborate, cadmium perchlorate, gold sulfite, and cobalt hardened gold.
• Substitute sodium bisulfite and sulfuric acid for ferrous sulfate in order to oxidize chromic acid wastes, and substitute gaseous chlorine for liquid chlorine in order to reduce cyanide reduction.
• Replace hexavalent chromium with trivalent chromium plating systems.
• Replace cyanide with non-cyanide baths.
• Replace conventional chelating agents such as tartarates, phosphates, EDTA, and ammonia with sodium sulfides and iron sulfates in removing metal from rinse water which reduces the amount of waste generated from precipitation of metals from aqueous wastestreams.
• Replace methylene chloride, 1,1,1-trichloroethane, and perchloroethylene (solvent-based photochemical coatings) with an aqueous base coating of 1% sodium carbonate.
• Replace methanol with nonflammable alkaline cleaners.
• Substitute a non-cyanide for a sodium cyanide solution used in copper plating baths.
• Send drag-out waste to another company for waste exchange.
• Reuse rinse water.
• Reuse drag-out waste back into process tank.
• Recover process chemicals with fog rinsing parts over plating bath.
• Evaporate and concentrate rinse baths for recycling.
• Use ion exchange and electrowinning, reverse osmosis, and thermal bonding when possible.
• Use sludge slagging techniques to extract and recycle metals.
• Use hydrometallurgical processes to extract metals from sludge.
• Convert sludge to smelter feed.
• Remove and recover lead and tin from boards by electrolysis or chemical precipitation.
• Install a closed loop batch treatment system for rinsewater to reduce water use and waste volume.
• Install an electrolytic cell which recovers 92 percent of dissolved copper in drag-out rinses and atmospheric evaporator to recover 95 percent of chromic acid drag-out, and recycle it into chromic acid etch line.
• Oxidize cyanide and remove metallic copper to reduce metal concentrations.

ETCHING OPERATIONS

• Substitute sodium persulfate etchant (acid etch solution) with hydrogen peroxide/ sulfuric acid.
• Recover copper by electrolytic processes.

SEMICONDUCTOR MANUFACTURING

• Install a system (e.g., the CALFRAN process) to reduce pressure to vaporize water at cooler temperatures, recycle water by condensing the vapors in another container, and concentrate and precipitate solutes.
• Reduce chrome waste generation by:
  1. Installing a rain cover on outdoor tanks to reduce chrome waste
  2. Treating on-site with caustics and sodium bisulfite to reduce chrome VI liquid to chrome III sludge
  3. Repairing water leaks in process rinse tank to reduce chrome waste.
• Replace chlorinated solvent baths with a non-hazardous product to reduce, and later, eliminate use of chlorinated solvents.
• Convert an open-top still into a closed loop system to recycle Freon 113.
• Use Athens system to reprocess sulfuric acid generated during wafer fabrication operations. The acid is heated to boil off water and other impurities, purified through distillation, and pumped back into wet stations to continue wafer processing.

PRINTED WIRING BOARD MANUFACTURING

• Modify sludge pretreatment processes by
  1. Adding flow control valves
  2. Installing metal recovery equipment
  3. Adding of deionization system.
• Redesign board during board assembly.
• Install a system (e.g., CALFRAN process) to reduce pressure to vaporize water at cooler temperatures, recycle water by condensing the vapors in another container, concentrate and precipitate solutes.
• use alternatives to wet chemical processes, including
  1. Mechanical cleaning as an alternative to chemical methods
  2. Process efficiency improvements for applying photopolymers, printing, and developing
• Alternative processes for connecting the PWB layers together and alternatives to lead-based soldering involving the use of lasers, reactive gases, or ultrasonics.
• Substitute semiaqueous or aqueous photoresist for 1,1,1-trichloroethane (TCA) and methylene chloride during board manufacturing.
• Substitute no-clean fluxes for CFC 113 and TCA during board assembly.
• Substitute aqueous clean fluxes for CFC 113 and TCA during board assembly.
• Substitute semi-aqueous cleaning materials for CFC 113 and TCA during board assembly.
• Substitute other solvents for CFC 113 and TCA during board assembly.
• Segregate wastewater sludge to prepare for metal recovery.
• Remove and recover lead and tin from boards by electrolysis - chemical precipitation.
• Install a system (e.g., Low Solids Fluxer) which applies flux to printed wiring boards, leaves little residue, and eliminates the need for cleaning with CFCs.
• Substitute for CFC 113 used in defluxing with:
  1. Fully aqueous system using water soluble fluxes
  2. Aqueous system using saponifiers to remove rosin based fluxes
  3. Semi-aqueous system using terpenes as a solvent
  4. Hydrogenated CFCs with chlorinated solvents.
• During tin-lead electroplating process, substitute fluouboric acid with:
  1. Organic sulfonic acid (OSA) plating
  2. Acid tin sulfate plating which eliminates lead use
  3. Hot air leveling
  4. Conductive, solderable polymer solutions

CATHODE RAY TUBE MANUFACTURING

• Reduce building of contamination in bath solutions by increasing process efficiency (e.g., implement ion exchange technology).
• Replace lacquer in panel preparation with a wax-like material similar to floor wax. It provides the necessary coating without a high volatile organic compound (VOC) content. One potential drawback, however, is the use of ammonia.
• Replace Freon as a cleaning agent for removing particulate contaminants from panel mask frames with air blow cleaning and an aqueous wash. (Nearly all CRT manufacturers have implemented this change.)
• Identify less hazardous cleaning chemicals, such as isopropyl alcohol, as alternatives to acetone or chlorinated solvents in maintenance and cleanup processes.
• Find substitutes for chromium-based photoresists.
• Identify alternatives to the lead-based frit used in sealing the funnel with the panel mask.
• Regenerate acids for glass cleaning and frit removal in waste glass recovery operations using existing technologies and equipment.
• Reclaim and reuse photoresists from one of the panel preparation processes.
• Recover soluble lead generated during the waste glass recovery operation by ion exchange resins. Reuse in lead smelting operations.
• Improve phosphor solution recovery and recycling efficiencies to further reduce discharge of metals to the environment.
• Reduce or recover the following:
  1. Chrome wastes
  2. Cleaning materials (hydrofluoric acids)
  3. Furnaces slag
  4. Cullet dust
  5. Fugitive dust
  6. Refractory brick wastes
  7. Alcohols