A soil remediation method for treating contaminated soil includes combining a dielectric carbonaceous nanomaterial with the contaminated soil to yield a composite contaminated soil, and irradiating the composite contaminated soil with microwave radiation to yield a remediated soil. The composite contaminated soil includes at least 1 wt % of the dielectric carbonaceous material, and the microwave radiation provides an energy input of at least 2.5 kWh per kilogram of the composite contaminated soil.