Optimization of the method wastewater treatment of unit bovine hides's unhairing liming

The mean object of this work is to evaluate the pollution degree of the various operating units (capacity of 2.5 tons of cattle/day) of tanning hide treatment,and treat effluents of the unit unhairing-liming by precipitation. the physico-chemical and biological characterization of wastewater studied operating units and the final discharge shows that the waters of all units are slightly basic,with a low biodegradable organic load and absence of fecal bacteria,but with a low concentration of flora mesophilic aerobic total. settling of all characterized wastewater for one hour allowed a polluting load reduction of 10 to 35% with the exception of sulfide ions and electrical conductivity of the effluent have not changed almost their concentrations. the treatment of settled effluents,characterized by high load sulfide ions,of unhairing-liming unit by ferric chloride in basic medium has contributed to the elimination of approximately 90% of these ions as a precipitate. © 2017,university of mohammed premier oujda morocco.