METHOD OF TREATING INDUSTRIAL WASTE WATERS CONTAINING COMPLEX SALTS OF HEAVY METALS

摘要

A process for the detoxication of waste slurries, in particular from the leather and skin industry, containing heavy metal salt complexes and organic materials comprises treating a suspension containing at most 100 kg/m3 of solid material with sulphuric acid and/or a mineral acid mixture composed of at least 30% by weight of sulphuric acid. The acid liquid containing the heavy metal salts is separated from the slurry, and the solution is neutralized; the metal salts are precipitated, purified and the organic slurry is washed to make it metal ion- and acid-free.