Heavy metals pose a serious threat and damage to ecological health when released into the environment. n-HFP is usually used to remediate soils contaminated with heavy metals, but its ability to solidify heavy metals is limited. FA has good ability to trap heavy metals due to its abundant oxygen-containing functional groups. However, the solubility of FA in water limits its application in the field of heavy metal removal. In this paper, n-HFP@FA was prepared by co-precipitation method. Through FT-IR and BET analysis, the oxygen-containing functional groups and specific surface area of n-HFP@FA increased due to the addition of FA. The adsorption behaviour of n-HFP@FA on Pb, Cd, and Cu followed the pseudo-second-order and Langmuir isotherm models. In addition, the maximum adsorption capacities of n-HFP@FA for Pb, Cd, and Cu were 371.1, 190.5, and 129.75 mg/g, respectively. As shown by FT-IR and XPS analysis, the main mechanisms of Pb, Cd and Cu removal by n-HFP@FA are: complexation, electrostatic and precipitation. The n-HFP@FA showed high removal rates of Pb, Cd, and Cu in soil leachates of different pH. In the soil remediation experiments, the BCR method and Pearson correlation analysis showed that the acid-soluble, reducible and oxidizable fractions of Pb, Cd, and Cu in the soil were effectively converted into a more stable residual fraction. This study opens up a prospect for the application of n-HFP@FA composites in the remediation of contaminated soil.
Soil pollution by diesel fuels is a worldwide environmental problem, but little research has been carried out into on-site techniques for remediation of soil polluted by waste solvents. This study compared chemical oxidation and soil washing methods for their efficiency and environmental and economic impacts. Soil was spiked with 0 # diesel to simulate an actual pollution level of about 1260 mg/kg total petroleum hydrocarbon (TPH). Fenton-like oxidation eliminated 90.4% of the TPH with a Fe 2+ :H 2 O 2 ratio of 1:10 in 5 d compared with 25.8% removal by the activated persulfate method under the same conditions. In washing tests, sodium dodecylbenzenesulfonate and Tween 80 were both unsuitable for TPH washing, while ultrapure water removed 36.1% of TPH in 75 min. Only the Fenton-like oxidation technique met remediation goals based on the screening values of the Guideline for Risk Assessment of Contaminated Sites. The environmental impact and economic assessment of techniques demonstrated the superiority of water washing for dealing with low-degree TPH contamination.
危险品化学品经营许可证（带存储）