Characterization of Batu and Walia Tanneries` Solid Wastes

The research was conducted at Batu and Walia tanneries to determine quantities and characteristics of the solid wastes, to identify management problems and to propose possible solutions. Solid wastes generated at the tanneries during tanning are raw trimmings,salts, hairs, fleshings, pelt splits and trimmings, wet blue splits and trimmings, shavings, buffing dust, crust and finished leather trimmings. parameters such as pH, moisture, carbon, nitrogen, volatile organic compound, ash, Cr, Mn, Al, Cu and Zn contents of the solid wastes samples were determined.Samples were digested by microwave digester and trace metals were analyzed by using ICP-OES 720.Moisture content of the solid wastes ranges from 9.9% in buffing dust to 71% in fleshings.C/N ratio ranges from 3.82:1 in raw trimming waste to 9.96:1 in wet blue trimming. These indicate that C:N ratios are below recommended suitable values for composting. Therefore,other carbon sources have to be added to tannery solid wastes for compost making.There is no sorting of the solid wastes based on their types.Tanneries have to implement cleaner production systems to manage the solid wastes in environmentally friendly manner.