Zebene Kiflie (Prof.)Liya Shawel2024-07-312024-07-312023-09https://etd.aau.edu.et/handle/123456789/3355Many tanning industries use many chemicals such as chrome, lime, sodium sulfide and ammonium salts etc. in different processing stages which can be hazardous for human health and the environment. The pre-tanning (liming) stage uses lime and sodium sulfide for dehairing skins and hides. These, however, result in significant increases of the biological oxygen demand (BOD), chemical oxygen demand (COD), suspended solids, etc. the objective of this thesis work is to investigate the potential of protease enzyme as an alternative to lime-sulfide for dehairing application. Protease enzyme was extracted from Ficus Sycomorous fruit using isolation of enzyme from plant source method. The proteolytic activities of the extracted enzyme were characterized by spectrophotometer and showed 18.1892 U/ml. Effects of different operating conditions such as protease enzyme concentration, temperature and time on the dehairing performance were investigated. The enzymatic de-haired skin was analyzed by scanning electron microscope (SEM). Results show that the enzyme was able to dehair 93% fresh goat skin within 17hr at 8 pH and 350C. In addition, the generated waste was characterized and showed reduction of 87%BOD, 93%COD, 86.5%TDS and 96.5%TSS. The use of ficin protease enzyme on goat skin resulted in a highly promising hair removal efficiency as alternative to lime-sulfide chemical de-hairing processen-USficindehairproteolytic activitiesscanning electron microscopic (SEM)Thesis