Kinetic analysis and parametric optimization for bioaugmentation of oil from oily wastewater with hydrocarbonoclastic Rhodococcus pyridinivorans F5 strain

Bioaugmentation is the most coveted bioremediation technology in present days that is being widely quested around the world for the treatment of wastewater. The present study thus investigates the bioaugmentation capability of the isolated hydrocarbonoclastic bacterium Rhodococcus pyridinivorans F5 in polymeric entrapment to degrade hydrocarbons from oily wastewater. The strain showed high hydrocarbon tolerance ability as high as 8% (v/v) hydrocarbon concentration. Optimization of the growth conditions was simulated using response surface methodology (RSM), which was found and validated at the temperature 37 degrees C with neutral pH for a wide range of salinity. Maximum percentage degradation of hydrocarbon was seen as 79(+/- 0.03)% for the system comprising of both free and emulsified form of oil using the isolated strain in free bacterial suspension state. While the degradation percentage was increased to 86(+/- 0.028)% with the cell entrapped alginate bead without the presence of activated carbon as the doped agent. After doping activated carbon with the alginate bead the percentage degradation was further increased to 95(+/- 0.02)%. It was studied that with the entrapment technology the sustainability of the technology enhances because of the enhanced recyclability of the microbial cells in bioaugmenting the oil from oily wastewater. Statistical interpretation showed that the degree of hydrocarbon degradation was significantly sensitive to both the state of presence of oil in an oily-water system (F = 444.8 > F-critical = 6.9) and the presence of bacterial form (either free bacterial suspension or immobilized state) (F = 168.1 > F-critical = 6.9). (C) 2020 Elsevier B.V. All rights reserved.