College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, China.
Zhejiang Fangyuan New Material Co., Ltd., Taizhou 318000, China.
J Hazard Mater. 2022 Aug 15;436:129062. doi: 10.1016/j.jhazmat.2022.129062. Epub 2022 May 6.
Disposal of organic-contaminated soil through ceramsite production can not only generate ceramsite with acceptable properties but also completely remediate the organic-contaminated soil owing to high treatment temperature. However, the removal mechanism of organic pollutants and the gas-solid phase distribution of the pollutants remain unclear. In this study, coking contaminated soils with high concentrations of polycyclic aromatic hydrocarbons (PAHs) and petroleum hydrocarbon (PHC) were used to prepare ceramsite at 1160 °C. The quality of ceramsite met the required product standard when the disposal ratio of contaminated soil was up to 60%. The concentration of PAHs and PHC in the soil was 57.7 mg kg and 255 mg kg. After the experiment, almost no PAHs and PHC were found in the ceramsite. High-ring PAHs were dominant in the flue gas when using model soil spiked with PAHs. Computed tomography scanning indicated that cracks developed in the ceramsite when the temperature was higher than 200 °C. High-temperature in-situ thermal analysis showed that when the temperature was increased to 400 °C, the pollutant from the interior of ceramsite would flow into the flue gas with the released volatile matter. Thermal desorption and degradation of PAHs were the main mechanisms of pollutant removal.
通过陶粒生产处理有机污染土壤不仅可以生产出性能可接受的陶粒，而且由于处理温度高，还可以彻底修复有机污染土壤。然而，有机污染物的去除机制和污染物的气固相间分布仍不清楚。在这项研究中，使用高浓度多环芳烃（PAHs）和石油烃（PHC）的焦化污染土壤在 1160°C 下制备陶粒。当污染土壤的处理比例高达 60%时，陶粒的质量符合所需的产品标准。土壤中 PAHs 和 PHC 的浓度分别为 57.7mgkg 和 255mgkg。实验后，陶粒中几乎没有发现 PAHs 和 PHC。在用多环芳烃污染的模型土壤进行实验时，在烟道气中发现高环 PAHs 占主导地位。计算机断层扫描表明，当温度高于 200°C 时，陶粒内部会出现裂纹。高温原位热分析表明，当温度升高到 400°C 时，来自陶粒内部的污染物会与释放的挥发性物质一起流入烟道气中。热解吸和 PAHs 的降解是去除污染物的主要机制。
