生物炭-硅酸钙联合修复铅镉污染土壤的持续性效应.

This study evaluated the remediation effect and stability of palm biochar combined with calcium silicate on lead-cadmium（PbCd）co-contaminated soil, by determining the pH, Pb content, and Cd content in soil solution and edible parts of vegetables in pot experiments. The results demonstrated that compared with the control, addition of a passivation agent could effectively increase the pH value, and substantially reduced the Pb and Cd content in soil solution, and in the edible part of Chinese cabbage by 62.20%–96.77% and 92.76%, respectively. Most of the Pb and Cd contents in the edible part met the National Food Safety Standards（GB 2762—2022）after soil remediation. The results of planting suitability analysis revealed that there were consistent trends of heavy metal concentration in the edible parts and enrichment coefficients of the five tested vegetables. Chinese cabbage and amaranth had the strongest accumulation ability for Pb and Cd, respectively. Soil with Pb<500 mg·kg-1, was more suitable for planting Chinese chives, amaranth, cabbage, and Chinese cabbage; whereas soil with Cd>0.6 mg·kg-1 and/or Pb>500 mg·kg-1, was not suitable for planting any of the five vegetables. This study proves that the continuous remediation effect of the passivator provides technical reference for soil remediation, as well as suggestions for suitable vegetable planting in low-medium pollution risk areas. [ABSTRACT FROM AUTHOR]