Thermal remediation has been widely used for the removal of polycyclic aromatic hydrocarbon (PAH) from contaminated soil. The method has a high removal rate for semi-volatile organic pollutants; however, soil functionality is affected by the method because of the alteration of the soil properties. In this study, experimental soil was impregnated with phenanthrene (Phe), pyrene (Pyr), and benzo(a)pyrene (BaP); after natural air-dry aging, the thermal remediation experiment was carried out, using a tube-furnace and thermal gravimetry–Fourier transform infrared (TG-FTIR) equipment. More than 84% of the Phe and Pyr were lost in the aging stage, whereas the BaP was stable with 41% retention in the soil. After the thermal treatment, the desorption and decomposition of the pollutants and organic matter led to the removal of the PAHs; about 1% of the PAHs remained in the soil treated at 400 °C. The presence of the PAHs can promote the thermal reaction by slightly reducing the reaction activation energy by ~7−16%. The thermal remediation had a significant influence on the physical properties of the soil and destroyed the bioavailability by reducing the organic matter content. Therefore, a comprehensive consideration of effective PAH removal while preserving soil functionality may require a low temperature (100 °C) method for thermal remediation.

Rapid industrial development increases soil contamination risks in suburban agricultural areas; however, the extent and sources of heavy metal(loid)s pollution in the soil during this process are not well understood. This study investigated the concentrations, spatial distribution, and potential risks of heavy metal(loid)s (As, Hg, Cd, Cr, and Pb) in soil and wheat samples from an agricultural area. The study found that soil Cd was the main pollutant with the highest enrichment factor of 15.9 with 21.6% of the wheat samples having Cd concentrations exceeding the China's limit of 0.1 mg/kg. Soil As, Cd, Hg, and Pb were concentrated in the northwest, while Cr was high in the southeast. Soil Cd contamination is more severe than other heavy metal(loid)s and poses a slight ecological risk. Monte Carlo simulations showed that the hazard quotient for all five heavy metal(loid)s in wheat was less than 1, with Cd being the highest. 1.35% of children and 0.87% of adults exceeded the carcinogenic risk level for Cd, while 0.54% of children exhibited above the threshold for Cr. Children were the most sensitive to heavy metal(loid)s exposure in contaminated areas, with heavy metal(loid)s) concentration in wheat being the key factor influencing health risks. Source apportionment via the PCA-APCS-MLR model and correlation analysis revealed that the soil Cd originated from agricultural activities and industrial-traffic. This study assessed soil heavy metal(loid)s pollution, ecological risks, sources, and health risks to residents from wheat consumption, providing evidence for managing soil contamination and food safety.