Low Cost Recovery and Reuse of Chromium from Spent Chrome Liquor of Hazaribugh Tannery

Abstract

Chrome and lime tannery waste liquors that produced from cow shoe upper leather manufacturing were collected from East Asia Tannery in
Hazaribagh area near Dhaka city. The chrome effluent was treated with different volumes of lime effluent with continuous stirring. At the
volume ratio of lime effluent to chrome effluent, 1:5 the total precipitation of chromium occurred. The pH value was observed 7.5  0.1 at
the stage of complete precipitation. The chromium precipitate was then collected through filtering, washed three times with distilled water,
air-dried and grinded. The grinded chrome powder was converted to basic chromium sulfate solution using concentrated sulfuric acid and
sodium hydroxide solution. Goatskins were retanned as shoe upper leather in conventional method using converted basic chromium sulfate
solution. Physical and chemical parameters of this manufactured leather were done and found to be similar to shoe upper leather using
commercial basic chromium sulfate. The filtrate obtained after chromium recovery was safely disposed after aeration.