In this study, municipal waste pyrolytic char (PEWC) was prepared by pyrolysis from municipal solid waste extracted in landfills, and Fe-based modified pyrolytic char (Fe-PEWC) was prepared by modification. Focusing on the evaluation of the stabilization capacity of Fe-PEWC for vanadium (V) and chromium (Cr) in soils, the effects of PEWC addition on soil properties, bioavailability and morphological distribution of V and Cr, ryegrass growth, and V and Cr accumulation were thoroughly investigated. The results of pot experiment showed that the application of PEWC and Fe-PEWC significantly (P < 0.05) improved soil properties (such as pH, EC, total nitrogen, available phosphorus, available potassium, and organic matter). After 42 days of cultivation, Fe-PEWC has a better fixation effect on heavy metals, and the bioavailable V and Cr of 3% Fe-PEWC decreased by 14.96% and 19.48%, respectively. The exchangeable state and reducible state decreased, while the oxidizable state and residual state increased to varying degrees. The Fe-PEWC can effectively reduce the accumulation of V and Cr in ryegrass by 71.25% and 76.43%, respectively, thereby reducing their toxicity to plants. In summary, modified pyrolytic char can effectively solidify heavy metals in soil, improve soil ecology and reduce the toxicity to plants. The use of excavated waste as a raw material for the preparation of soil heavy metal curing agent has the significance of resource recycling, low price, and practical application.

中文翻译：

---

使用铁改性热解炭同时固定 V 和 Cr 的有效性、污染土壤中的形态以及黑麦草中的积累

本研究以垃圾填埋场提取的城市固体废物为原料，通过热解制备城市垃圾热解炭（PEWC），并通过改性制备铁基改性热解炭（Fe-PEWC）。重点评价Fe-PEWC对土壤中钒(V)和铬(Cr)的稳定能力，PEWC添加对土壤性质、V、Cr的生物有效性和形态分布、黑麦草生长以及V、Cr的影响积累进行了彻底调查。盆栽试验结果表明，施用PEWC和Fe-PEWC显着（P < 0.05）改善了土壤性质（如pH、EC、全氮、速效磷、速效钾和有机质）。培养42天后，Fe-PEWC对重金属有较好的固定效果，3%Fe-PEWC的生物有效性V和Cr分别下降了14.96%和19.48%。可交换态和还原态有所减少，而氧化态和残余态有不同程度的增加。 Fe-PEWC可有效减少黑麦草中V和Cr的积累，分别减少71.25%和76.43%，从而降低其对植物的毒性。综上所述，改性热解炭可以有效固化土壤中的重金属，改善土壤生态，降低对植物的毒性。利用挖掘废物作为原料制备土壤重金属固化剂，具有资源循环利用、价格低廉、实用化的意义。