Integrating environmental, economic, and technological assessments for modified biochar materials in complex contaminated soil remediation.

Life cycle assessment (LCA) and life cycle cost (LCC) analysis were integrated to evaluate four modified biochars (acid/base-modified, magnetically modified, nano-modified, and organically modified) for complex, contaminated soil remediation. LCA ranked modified biochars in term of environmental impacts as follows: organic > nano > acid/base > magnetic. LCC analysis ranked biochars in terms of total costs as nano > organic > magnetic > acid/base. In physicochemical improvement, biochars ranked as magnetic > nano > organic > acid/base. Comprehensive assessment recommends acid/base-modified biochar for agricultural pollution, magnetically modified biochar for industrial sites (due to high adsorption and recyclability), organically modified biochar for domestic waste dumping areas, while nano-modified biochar is not primarily recommended owing to high cost and performance variability. The findings support decision-making by balancing environmental friendliness, cost effectiveness, and material properties across different contamination scenarios.