Effect of synthetic fatty liquor and neatsfoot oil as co-contaminants on the reduction of hexavalent chromium using Fusarium oxysporum and its kinetic study

The hexavalent chromium is one of the major carcinogenic components released during the tanning process and lots of work have been carried out on the reduction of hexavalent chromium via chemical and biological routes. Different fatty oils are also employed in the tanning process and have also been released as an effluent along with chromium. However, it is difficult to find a study on the reduction of chromium in the presence of other contaminant which would help to mimic the real-time complication of treating the tannery effluent. It is the first attempt on the reduction of hexavalent chromium in the presence of synthetic fatty liquor and neatsfoot oil using Fusarium oxysporum. The maximum percentage of chromium reduction was 73.62% and 60.28% in neatsfoot oil and synthetic fatty oil, respectively, for the initial chromium concentration of 25 mg/L. The biomass productivity was better with both neatsfoot oil and synthetic fatty oil, whereas the same has decreased with the presence of chromium. The reduction of chromium was found to follow the uncompetitive substrate inhibition kinetics than the general Michaelis–Menten kinetics. The kinetic parameters were calculated using particle swarm optimization algorithm, which were compared with the already reported data. The uncompetitive substrate inhibition kinetics was represented the experimental data in both the cases and the value of substrate inhibition constant was low in the case of neatsfoot oil compared with the synthetic fatty liquor.