Title : Bioremediation of Petroleum Refinery Wastewater Using Bacillus Subtilis IH-1 and Assessment of Toxicity
With the rapid expansion of the population and the modernization of civilization, environmental contamination from the petroleum refinery sector has surged, necessitating immediate repair.Petroleum pollutinh-degrading bacteria are common in nature and may use these molecules as carbon and energy sources. The microbial bioremediation of petroleum-related pollutuion. In this sttudy, a bacterial culture was obtained from petroleum-contaminated sludge in order to valorize PAHs and biodegrade petroleum waste water samples. Bacillus subtilis IH-1 was discovered as the bacterial strain after it was examined. After 6 days, the bacteria had degraded 20.3% naphthalene and 25.9% phenanthrene. The treatment of waste water samples was evaluated using physicochemical and Fourier-transform infrared spectroscopy (FTIR) analysis, which revealed that the level of pollutants was high and exceeded the allowable limits. However, after bacterial degradation there was a significant reduction in pollution parametres. The phytoxicity test using v. mungo revealed a concentration-dependent decrease in seed germination, root length, shoot length, and biomass when compared to the control. The mitotic index of A. cepa root tips planted in varied concentrations of petroleum refinery wastewater samples was significantly lower than thatof the control root tip exposed to tap water, indicating the induction of cytotoxicity. However, after treatment with a bacterial strain, both phytotoxicity and cytotoxicity dramatically decreased, indicating that the bacterium has the capacity to breakdown the harmful contamination of petroleum wastewater and might be employed in large-scale studies.