Investiation on the pollution release characteristics of subgrade base materials prepared by thermal desorption residues of oil-based cuttings

The thermal desorption residues of oil-based drilling cuttings’ final destination managements are still strict because of the unclear pollution characteristics of its resource products. The thermal desorption residues were prepared into subgrade base materials, and the semi-dynamic leaching tests were used to simulate the leaching characteristics of pollutants under extremely acidic conditions. In the semi-dynamic test, the concentrations of pollutants such as naphthalene, anthracene, benzo(a)anthracene, dibenzo(a,h)anthracene, Cd, and Zn meet the Class III water quality requirements of “Standard for groundwater quality”(GB/T 14848-2017). According to Fick’s second law, the release of naphthalene, anthracene, benzo(a)anthracene, dibenzo(a,h)anthracene, and Cd of leaching is dominated by diffusion; the release of benzo(a)pyrene and Zn of leaching is mainly dissolution. The release law and characteristics of pollutants were explored when thermal desorption residues were applied as subgrade base materials, which provided an important reference basis for the resource and utilization of thermal desorption residues.