Purpose

This research developed an innovative strategy to concurrently achieve efficient remediation of PCS and high-value resource utilization of the remediated soil.

Materials and methods

The combined treatment method of Fe₃O₄-assisted ball milling pretreatment and oxygen-limited pyrolysis was used to treat PCS and convert it into Fe-loaded carbonized soil (Fe-CS) to adsorb heavy metals in wastewater. The thermodynamic and kinetic models were used to fit the adsorption capacity and behavior of Fe-CS. The adsorption mechanism of heavy metals was analyzed and the contribution of each material component to heavy metal adsorption was quantified.

Results and discussion

The obtained Fe-CS has a high and rapid adsorption capacity for heavy metals and shows good magnetic properties. Both residual total petroleum hydrocarbon (TPH) and dissolved organic matter in the Fe-CS were removed with high efficiency. The maximal adsorption capacities of lead, copper, zinc, and cadmium ions are 888.79, 69.33, 77.52, and 47.37 mg/g, respectively. The heavy metals adsorbed in Fe-CS are mostly bound to carbonates, followed by bound to iron-manganese oxides and organic matters. The adsorption mechanism of Me²⁺ by Fe-CS mainly includes carbonate binding, complexation by metal oxides and oxygen-containing functional groups, and π coordination of unsaturated bond.

Conclusions

The Fe₃O₄-assisted ball milling pretreatment significantly improves the heavy metal adsorption performance of carbonized soil derived from PCS treated by pyrolysis, which significantly improves the resource utilization value of the remediated soil, and has good application potential in PCS treatment.

中文翻译：

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氧化铁球磨热解作为重金属吸附剂的石油污染土壤资源增值利用

目的

本研究开发了一种创新策略，可同时实现 PCS 的高效修复和修复土壤的高价值资源利用。

材料和方法

_{采用Fe 3} O ₄辅助球磨预处理和限氧热解联合处理方法处理PCS，将其转化为载铁碳化土(Fe-CS)吸附废水中的重金属。热力学和动力学模型用于拟合 Fe-CS 的吸附容量和行为。分析了重金属的吸附机理，量化了各材料成分对重金属吸附的贡献。

结果与讨论

所得Fe-CS对重金属具有高而快速的吸附能力，并表现出良好的磁性能。Fe-CS 中残留的总石油烃 (TPH) 和溶解的有机物均被高效去除。对铅、铜、锌和镉离子的最大吸附容量分别为888.79、69.33、77.52和47.37 mg/g。Fe-CS中吸附的重金属主要与碳酸盐结合，其次是与铁锰氧化物和有机物结合。^{Fe-CS对Me 2+}的吸附机理主要包括碳酸盐键合、金属氧化物与含氧官能团的络合以及不饱和键的π配位。

结论

Fe ₃ O ₄辅助球磨预处理显着提高了热解处理PCS炭化土壤的重金属吸附性能，显着提高了修复土壤的资源利用价值，在PCS处理中具有良好的应用潜力。