Removal of Fat Components in High TDS Leather Wastewater by Saline-Tolerant Lipase-Assisted Nanoporous-Activated Carbon.

The present investigation was carried out for the degradation of fatty components in high TDS containing wastewater (soak liquor) discharged from leather industry, and the degradation was achieved by saline-tolerant lipase-immobilized functionalized nanoporous-activated carbon (STLNPAC). The lipase was extracted from the halophilic organism, Bacillus cereus. The optimum conditions for lipase production such as time, 60 h; temperature, 50 °C; pH, 10; and substrate concentration, 2.5% (w/v) were determined through response surface methodology (RSM). The functionalization of NPAC was done by ethylenediamine/glutaraldehyde covalent interaction technique followed by the immobilization of saline-tolerant lipase onto FNPAC. The functional properties of STLNPAC were analyzed through instrumentation techniques such as TGA-DSC, FT-IR, XRD, and SEM images. The lipid content of soak liquor was removed by > 99% at HRT of 60 min using STLNPAC-packed bed reactor. The efficiency was evaluated by using UV-visible and FT-IR spectroscopic analyses. The degradation of lipids was best obeyed by pseudo first-order rate kinetics, and the rate constant was found to be 1.6 × 10-3  min-1 . The biodegradability index of soak liquor was increased from 0.322 to 0.426, highly favorable for the complete removal of organic components in subsequent operations.