Pollution prevention and waste minimization at a galvanizing and electroplating facility

Abstract

Pollution prevention, often referred to as source reduction, encompasses all activities that lead to reductions in the amount and/or toxicity of wastes. Waste minimization, on the other hand, refers to all activities including source reduction, on-site reuse, and recycling that lead to reductions in the amount and/or toxicity of waste generated, stored, treated, or disposed of by a given facility. Pollution prevention generally is regarded as the most cost-effective component of integrated waste management strategies. This paper describes an industrial pollution prevention program at an aging manufacturing facility in the Midwestern United States. The study focuses on metal electroplating and galvanizing. The facility under study produces fabricated metal products for farm and industrial use. The facility performs many operations including electroplating, conversion coating, cleaning, machining, grinding, impact deformation, shearing, welding, sand blasting, hot-dip galvanizing, painting, assembly and testing. Many of these processes result in the production of a variety of pollutants (gaseous, solid, and liquid) that must be disposed of in some fashion. For example, the electroplating line results in the production of acids and rinse water containing zinc and chromium and the hot-dip galvanizing line results in the production of acids and rinse water containing zinc and iron. All of these wastes must be treated as hazardous substances. The painting processes result in the production of used industrial acids, solvents, and chemicals used for cleaning and de-greasing metal components. Most of the recommended operational and process modifications were simple to implement, and their pay-back periods were fairly short.