Green Preservation of Goatskin to Deplete Chloride from Tannery Wastewater

Abstract

Globally, in wet-salting preservation, common salt (sodium chloride, NaCl) is generally used for the raw animal skin, which emits a huge amount of chloride-containing wastewater, affecting groundwater quality and human and plant life. Chlorides in tannery wastewater encourage salt-free or less-salt preservation methods of raw skin. In this study, an alternative salt-free "green method" has been described for goatskin preservation with rapidly growing obnoxious weeds like Sphagneticola trilobata leaf. The ‘green leaf paste' was applied on the flesh side of the raw goatskin and compared with the conventional wet-salting (50% NaCl) method for 28 days. Different parameters of both samples, like moisture, nitrogen, hydrothermal stability, and bacterial growth, were periodically assessed and compared. Shoe upper leather was produced from both preserved goatskins. After comparing with standards, the physical properties like tensile strength, elongation at break, and bursting strength satisfied the standard requirements. SEM images showed no deterioration to the fiber structure of both samples. Moreover, the suggested method reduces the pollution loads: chloride, total dissolved solids, biochemical oxygen demand, and chemical oxygen demand by 98.04%, 92.9%, 90.2%, and 85.5%, respectively. The overall assessment recommends that the salt-free ‘green method' utilizing S. trilobata leaf paste could be an attractive system over the conventional wet-salting method. Doi: 10.28991/HIJ-2021-02-02-03 Full Text: PDF