Chandrasekaran, B. (PhD)Melkamu, Kassahun2020-12-242023-11-282020-12-242023-11-282014-09http://etd.aau.edu.et/handle/12345678/24326Leather has remained a unique material for a long time. visco-elasticity and pore size distributions are two important properties of leather that have rendered it a unique material. The ability to breathe and readjust to volume fluctuations of the foot has made leather a unique material of choice in footwear industry. The environmental pollution problems pressures on chromium and forced the leather industry to find the possible alternatives. In the present study, a combination tanning system based on a quebracho –zinc tannage for the production of versatile leathers as a cleaner alternative is presented. A combination tanning system based on qubracho and zinc sulfate. (quebracho-Zn) leathers tanned using 8% quebracho followed by 6% ZnSO4.7H2O; resulted in shrinkage temperature is 87°C. The uptake of quebracho-zinc combination tanning system with quebracho (8%) and zinc (6% ZnSO4.7H2O) has been found to be better than the tanning system of quebracho and zinc tanning systems. The combination tanning system provides significant reduction in the discharge of COD, BOD5 and TDS in the wastewater. Quebracho-Zn combination tanning system resulted in leathers with good hygienic, bulk and strength properties. The work presented in this paper established the use of quebracho and zinc combination tanning system as an effective alternative cleaner tanning technology.en-UScombination tanning systemzinc sulfatequebrachoshrinkage temperaturehygienicbulkstrength propertiesThesis