Removal of high concentrations of polycyclic aromatic hydrocarbons from contaminated soil by biodiesel

Abstract

Solubilizing experiments were carried out to evaluate the ability of biodiesel to remove polycyclic aromatic hydrocarbons (PAHs) from highly contaminated manufactured gas plant (MGP) and PAHs spiked soils with hydroxypropyl-β-cyclodextrin (HPCD) and tween 80 as comparisons. Biodiesel displayed the highest solubilities of phenanthrene (420.7 mg$L -1 ), pyrene (541.0 mg$L -1 ), and benzo(a)pyrene (436.3 mg$L -1 ). These corresponded to several fold increases relative to 10% HPCD and tween 80. Biodiesel showed a good efficiency for PAH removal from the spiked and MGP soils for both low molecular weight and high molecular weight PAHs at high concentrations. Biodiesel was the best agent for PAH removal from the spiked soils as compared with HPCD and tween 80; as over 77.9% of individual PAH were removed by biodiesel. Tween 80 also showed comparable capability with biodiesel for PAH solubilization at a concentration of 10% for the spiked soils. Biodiesel solubilized a wider range of PAHs as compared to HPCD and tween 80 for the MPG soils. At PAH concentrations of 229.6 and 996.9 mg$kg -1 , biodiesel showed obvious advantage over the 10% HPCD and tween 80, because it removed higher than 80% of total PAH. In this study, a significant difference between PAH removals from the spiked and field MGP soils was observed; PAH removals from the MGP soil by HPCD and tween 80 were much lower than those from the spiked soil. These results demonstrate that the potential for utilizing biodiesel for remediation of highly PAH-contaminated soil has been established.

Rhizosphere effect on removal and bioavailability of PAHs in contaminated agricultural soil

“…PAHs in the soil were extracted using a mechanical chemical extraction procedure (Wu et al 2010;Guo et al 2016). 5 g soil was put into a glass bottle, then 1.5 g of sodium chloride, 10 mL of distilled water, 15 mL of dichloromethane, and 20 mL of acetone were added.…”

Enhanced Degradation of Benzo[α]Pyrene in Coal Tar Contaminated Soils Using Biodiesel

“…Following biodegradation and biodiesel breakdown, toxic response was seen to increase significantly for the non-stepwise amended experiments, while increase was not significantly noticed in the stepwise amended treatments. This increased toxicity may have been induced by the possible occurrence of residual toxic intermediates from the cometabolic degradation or transformation of recalcitrant PAHs [51], high acidity from the hydrolysis of the fatty acid methyl esters [52] or increased bioavailability of PAHs from the solvency effect of biodiesel [53,54].…”

Selection of oxidant doses for in situ chemical oxidation of soils contaminated by polycyclic aromatic hydrocarbons (PAHs): A review

“…Therefore, prior to oxidation, solubilizing agents such as surfactants [40,44,170,171], vegetable oils [172], co-solvents [53,151] or cyclodextrins [173] can be used in order to enhance PAH desorption and increase PAH availability.…”