Environmental Friendliness of Enzymatic Soaking and Unhairing Processes. Part 1: The Evaluation based on Settling Property of Wastewater

• 1、National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University,

Abstract：Enzymatic soaking and unhairing (ESU) processes are encouraged and widely adopted in leather manufacture for the reason of environment protection. The objective of this series of researches is to evaluate the environmental friendliness of these processes not only based on the quantity of pollutants in wastewater, but also on the wastewater treatability such as the settling property and biodegradability. The chemical sedimentation behaviors of ESU wastewater and the wastewater collected from conventional soaking and unhairing (CSU) processes were investigated and compared with each other in this paper. The results show that ESU wastewater has better treatability in terms of settling velocity, pollutant removal and sludge volume, which indicates that enzymatic soaking and unhairing processes are more environmentally friendly compared with the conventional chemical processes.

Keywords： leather-making process soaking unhairing enzyme environmental friendliness evaluation wastewater sedimentation