Abstract

European tanneries generate a large amount of sludge containing chromium and other substances, some of which may be hazardous in post-tanning operations. In the next few years it is expected that landfilling these high organic content residues will be restricted in the EU thus imposing the need for treatment. This work assesses wet oxidation (WO) using hydrogen peroxide as an alternative solution for reducing the volume of sludge and its organic content. The effects of temperature, time, H2O2 dose and pH in the WO of a tannery sludge with chromium are evaluated through laboratory tests carried out in the range of 100-250 ºC. Volume of sludge, total solids and volatile solids were determined in the experiments as well as total organic carbon and chromium on most of them.