SOLIDS DETOXIFICATION-METALS RECOVERY

Philipp, Enviroscience, Inc., and William Rostoker and J. Dvorscek, Rostoker, Inc. 

There are approximately 13,000 job and captive metal finishing shops and printed board shops in the USA. Almost all of these companies have installed waste water treatment systems to comply with the Clean Water Act (CWA). As a result, these companies generate toxic metal sludges which are regulated by the Resource Conservation and Recovery Act (RCRA). Compliance with these two Federal laws, in addition to laws passed by local, county and state regulatory agencies, can require industry to spend 10 to 15% of their sales dollar on compliance. 

Many treatment/storage/disposal facilities (TSD) have stopped handling F006 wastes due to their inability to meet the TCLP (Toxicity Characteristic Leaching Procedure) leachate limits (Federal Register 8-17-88). These limits are  

These metal leachate limitations are extremely difficult to meet with the Best Demonstrated Available Technology (BDAT) which is chemical stabilization technology proposed by the Federal EPA. The fact that no limit was proposed for cyanide adds uncertainty to chemical stabilization. TSD facilities do not want to put mixed wastes containing cyanides into their secure landfills which may have to be removed at a later date. Note that a 1972 U.S. silver dollar fails the TCLP test due to nickel. 

Compliance with the land ban has caused disposal costs to increase by 25% to over 150%. Finding an approved facility is becoming more difficult and the Federal EPA does not have a list of TSD facilities authorized to provide chemical stabilization services. The National Technical Information Service (NTIS) does publish a helpful manual (No. PB88-109699) entitled Directory of Commercial Hazardous Haste Management Facilities. The manual lists 250 facilities which handle metals wastes. 

---