Evaluation Of Non-Toxic Organic Solvents In The Metal Finishing Industry

The use of various organic solvents for cleaning/degreasing operations in the metal finishing industry is subject to a myriad of environmental regulations which address pretreatment practices, environmental releases, community right-to-know responsibility, and hazardous waste management. The long-term availability of selected chlorofluorocarbons (CFCs) which are widely used for degreasing operations is in jeopardy due to concerns regarding depletion of atmospheric ozone levels. As a result of these factors, there is a widespread interest in identification of substitute compounds for use in metal finishing applications which do not exhibit adverse environmental properties. The research objectives address evaluation of the potential for formation of toxic by-products upon chlorination of candidate substitute solvents as would be practiced in wastewater disinfection and/or alkaline chlorination for cyanide destruction. The experimental effort also includes limited evaluation of the biodegradability of the solvents via conduct of biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic halide (TOX). Criteria for selection of solvents for investigation include: (1) Elimination/minimization of halogen content, (2) Minimization of other listed materials, (3) Existing utilization in the industry for cleaning operations, (4) Acceptable flash point/safety considerations. The candidate solvents which are expected to be selected for experimental evaluation may include alkaline detergents, non-halogenated organics (e.g., amines, alcohols, surfactants), and petroleum hydrocarbons. Three solvents will be tested with final results anticipated in the summer of 1990