Recent developments for the removal of arsenic and antimony from processing waters of the glass industry

Abstract

Since 1990 the concentrations of arsenic and antimony in waste waters of the glass industry have been limited in the Federal Republic of Germany. Lead crystal, crystal, and a lot of special glasses contain arsenic and/or antimony which enter the processing waters when the glasses are ground or treated by acid polishing. Therefore, these waters have to be cleaned before entering the drainage ditch. Grinding waters can be recycled by the precipitation of arsenic and antimony by ferric ions, the precipitate being separated together with the glass abrasion products. In processing waters from the acid-polishing process, however, arsenic and antimony partly form fluorocomplexes which cannot be precipitated by ferric ions. A new waste-water treatment by quaternary ammonium ions which precipitate hexafluoroarsenate — in addition to existing neutralization equipments — will meet the new regulations.