Abstract:
The combination of bioremediation, biosurfactants and electrokinetic remediation as a hybrid system was evaluated for the possibility of enhancing the removal of petrochemical hydrocarbons from contaminated soil as a sustainable and effective replacement for ineffective conventional remediation methods in an optimized manner. To begin with, the toxicity of the biosurfactant was determined by examining the effect of the biosurfactant on plant growth and microbial growth. The independent effect of biosurfactant concentration, voltage, the distance between electrodes and multifactor interactions on the bio-electrokinetic remediation of petrochemical contaminated soil using a bench-scale electrokinetic system were then evaluated. The results revealed that the rhamnolipid biosurfactant did not have any observable inhibition effects on the growth of the test bacteria in 5 days since the growth under test solutions of 0 mg/L, 10 mg/L, 50 mg/L and 100 mg/L did not have any significant differences. On the other hand, the biosurfactant affected root elongation and germination of the three test vegetables. Still, SDS had more substantial adverse effects represented by extremely low values of germination index as compared to the biosurfactant. The bio-electrokinetic remediation of soil revealed that a combination of the highest voltage of 30 V, the lowest electrode spacing of 185 mm and the highest biosurfactant concentration of 84 g/L had the highest microbial growth of 11.52 CFU/mL and hydrocarbon removal of 92% as compared to other configuration combinations. Microbial growth and hydrocarbon removal were mainly affected by voltage and biosurfactant concentration as the independent variables.
