Optimization of in Vitro Experimental Conditions for the Bioavailability of Polycyclic Aromatic Hydrocarbons (PAHs) in Soil

Amid rapid urbanization and industrial expansion, the ecological environment has suffered degradation, intensifying soil pollution. China's Soil Environmental Quality Standards reveal that polycyclic aromatic hydrocarbons (PAHs) surpass permissible levels in numerous areas, reaching as high as 36.3%. The presence of PAHs can trigger a chain reaction of pollution, affecting soil, water, and air due to their biological toxicity. This escalation poses a significant threat to the overall ecological equilibrium, ultimately jeopardizing the integrity of the entire environment. Contaminated soil impacts food safety. Thus, efficient extraction of four organic pollutants (benz(a)anthracenee, anthracene, chrysene, Benzo[k]tetraphene) is crucial for accurate site assessment. In this study, poly 2,6-diphenyl-p-phenylene oxide enhances PAHs' extraction accuracy through in vitro simulations, addressing soil bioavailability. The effects of solid–liquid ratio, tenax content and choline salt on PAHs extraction were evaluated by orthogonal test. The solid-to-liquid ratio had the greatest impact on the extraction of PAHs in the simulation experiments, with anthracene reaching optimal extraction at a solid-to-liquid ratio of 250 mL, 1.5 g poly 2,6-diphenyl-p-phenylene oxide, and 3.5 g bile salt; benz(a)anthracenee at a solid-to-liquid ratio of 250 mL, 1.5 g poly 2,6-diphenyl-p-phenylene oxide, and 3.5 g bile salt; chrysene at a solid-to-liquid ratio of 250 mL, 0.75 g poly 2,6-diphenyl-p-phenylene oxide, and 6.0 g bile salt; and Benzo[k]tetraphene at a solid-to-liquid ratio of 250 mL, 0.75 g poly 2,6-diphenyl-p-phenylene oxide, and 3.5 g bile salt.