Combinations of Surfactant Flushing and Bioremediation for Removing Fuel Hydrocarbons from Contaminated Soils: Fid-Bau Portal

Combinations of Surfactant Flushing and Bioremediation for Removing Fuel Hydrocarbons from Contaminated Soils

Yan, Guangxu / Ma, Wenfeng / Chen, Chunmao / Wang, Qinghong / Guo, Shaohui / Ma, Jie

A laboratory study was conducted to evaluate the contaminant removal efficiency of four soil flushing approaches (water flushing, surfactant flushing (Tween‐80), bioremediation + water flushing, and bioremediation + surfactant flushing) in remediating diesel‐contaminated soil. Two types of soil (sandy loam and silt loam) were studied. Bioremediation was conducted by the combination of bioaugmentation (adding a diesel‐degrading microbial mixture) and biostimulation (adding nitrogen and phosphorus nutrients). Sandy loam, with lower organic carbon content and higher permeability, had higher total petroleum hydrocarbon (TPH) removal efficiency than silt loam for all four flushing treatments. Compared to water flushing, surfactant flushing significantly enhanced the TPH removal efficiency for both sandy loam and silt loams. In contrast, bioremediation alone (without combining with surfactant flushing) failed to enhance the TPH removal efficiency for sandy loam and silt loam. The likely reason was that migration and delivery of the inoculated TPH‐degrading microorganisms was constrained by the soil porous matrix, preventing the microorganisms from spreading over the entire contaminated area. Surfactants can enhance bioremediation efficiency by facilitating the migration of degrading microorganisms and increasing contaminant bioavailability. A combination of surfactant flushing and bioremediation had the highest TPH removal efficiency (77.1% for sandy loam and 46.9% for silt loam) among the four flushing treatments. Overall, combining surfactant flushing with bioremediation appears to be a promising remediation strategy for sites contaminated by fuel hydrocarbons.