Environmental Science and Engineering Division, Central Leather Research Institute (CLRI), Council of Scientific & Industrial Research (CSIR), Adyar, Chennai, Tamil Nadu, 600 020, India. [Email]
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.