Influence of core-shell structure design on the preparation of oil-contaminated soil ceramsite and the pollutant decomposition effect

With the growing severity of oil-contaminated soil, its remediation technology has received increased attention. In this study, oil-contaminated soil is granulated into a core, covered with a layer of clean material, and sintered at a high temperature to make a core-shell structured ceramsite that can be used as building aggregates. The results showed that the cylinder compression strength, bulk density and 1 h water absorption of the sintered core-shell structure ceramsite is 9.1 MPa, 1134 kg/m³ and 4.36 %. Furthermore, in comparison with the conventional ceramsite, the core-shell structure process generated 26.9 % more CO₂. This indicates that the design of the core-shell structure makes it easier for the organic gases in the oil-contaminated soil to crack and release CO₂ and H₂O, reducing the tail gas pollution problem. After the process, the alkane organic matter in the ceramsite was removed, and the C content was significantly reduced. This method provides a new approach for the preparation of ceramsite for organic contaminated soil.