Efficient microwave remediation on naphthalene contaminated soil using a multifunctional bluecoke-based conditioner.

The remediation of organic-contaminated soil using microwave heating is widely concerned because of its advantages of low-cost, high efficiency, and short processing time. In the present work, the bluecoke-based conditioner (KHCO₃@BC) prepared by ultrasonic impregnation was employed to further improve the removal efficiency of naphthalene. The removal efficiency of naphthalene and the characteristics of remediated soil and by-products were investigated via experimental calculation, analysis of physical and chemical properties of soils, field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and gas chromatography-mass spectrometry (GC–MS). Besides, the removal process of naphthalene in microwave remediation was presented. Results indicated that the maximal removal of naphthalene by using KHCO₃@BC-assisted microwave remediation reached 96.46% with the highest temperature of 575 ℃, when 4 wt% of KHCO₃@BC conditioner was added, microwave power was 700 W, and heating time was 25 min. The content of total K and available K in remediated soil rose to 2.03 and 0.51 g/kg, thus improving the inorganic fertilizer of remediated soil. The size of soil particles significantly decreased after microwave remediation, which optimized the mechanical component of remediated soil. The removal process of naphthalene in microwave remediation mainly contained the gas stripping and naphthalene vaporization. The prepared KHCO₃@BC conditioner could realize the removal of contaminants, and increase K fertilizer for acid organic-contaminated soils in microwave remediation. [ABSTRACT FROM AUTHOR]