Lower salt combination of waste mustard oil cake for goatskin in preservation: Salinity reduction in tannery effluent

Abstract Sodium chloride (NaCl), a globally used preserving agent, creates a large amount of chloride pollution known as salinity during soaking in the tannery. Increased salinity affects not only water quality but also the ecological balance. This study is focused on the minimization of sodium chloride (NaCl) use in goatskin preservation. The preliminary experiment revealed that a combination of 5% grounded mustard oil cake + 5% NaCl could be effective for the preservation of goatskin. Based on a preliminary experiment, the combination of preserving agents was applied on freshly flayed goatskin and assessed for 28 days considering parameters—moistness, Total Kjeldahl Nitrogen, hydroxyproline, microbial analysis, and hydrothermal stability. Gas chromatography–mass spectrometry (GC–MS) was performed with ethanol extract to identify the antimicrobial activity of mustard oil cake. The physicomechanical properties of produced leather were comparable to the standard requirements. Scanning electron microscope (SEM) images represented an intact form of a tanned collagen bundle. Pollution load of chloride content, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were reduced to 40.4%, 40.7%, and 48.4%, respectively, in soaking wastewater. Thus, a combination of mustard oil cake with the lower NaCl could be an eco‐friendly preservation technique to reduce pollution in the tannery wastewater.