Abstract

A laboratory investigation showed that the amount of suiphide in used lime-sulphide liquors could be reduced greatly by aeration with diffused air in the presence of manganous chloride. Pilot scale trials at three tanneries in which the composition of the waste sulphide liquors varied widely confirmed these findings when vclumes of liquor varying from 500 to 1,500 gallons were used. Preliminary experiments to develop a con tinuous flow process are also described.