Evidence for adsorbable organic halides in the beamhouse, tanning and posttanning processing of ovine skin

The presence of the adsorbable organic halides (AOX) in treated Spanish tannery effluents has pushed us to investigate the source and origin of these contaminants from the tanning process. The auxiliary products containing organohalides used in the fatliquoring bath seem to be the main source of adsorbable organic halides in the wastewater. However, important concentrations of adsorbable organic halides have been found in other process wastewaters, and they are not eliminated in the physical and chemical wastewater treatments. Nevertheless the source of these adsorbable, organic halides is unknown. Thus, the main objective of this study was to carry out determinations of AOX and some other physical and chemical parameters of the wastewater generated in the tanning plant to characterise the wastewater of each process. The results reveal that the most important sources of AOX are the fatliquoring, tannage and pickling baths.