ARSENIC WASTE REDUCTION IN THE ELECTRONICS INDUSTRY

Darryl W. Hertz and Richard M. Holland Ebasco Environmental Services 

Many electronic companies in the State of California create a substantial volume of arsenic waste through the processing or manufacture of gallium arsenide (GaAs) microchips. Since the concentration of arsenic in wastewaters or sludges usually exceeds disposal limits for sewer and municipal landfills, these wastes are quite often treated and disposed to a Class I hazardous landfill. This practice is undesirable environmentally and economically as a long-term mechanism for waste disposal. 

Phase I of this project reviewed various processes to reduce, recycle and/or treat arsenic-laden wastes in a manner such that costs and disposal to the land are significantly reduced. The methods evaluated at various manufacturing stages included, buc were not limited to, separation, precipitation/fixation, ion exchange, and arsine generation. The information from Phase I was suitable for the design of a pilot scale treatment facility. 

Current findings from Phase II indicate that filtration of gallium-arsenide particulates from wastewater streams prior to entering Hewlett Packard s Hydrofluoric (HF) wastewater treatment facility will result in the following benefits  

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