Unlocking nature-based solution potential: Life cycle assessment of groundwater remediation at operating industrial sites

While life cycle assessment (LCA) has been extensively applied for environmental impact quantification in brownfield remediation, its systematic implementation in guiding groundwater contamination control at operational industrial facilities, where large-scale in-situ remediation is often constrained by ongoing activities, remains less explored. This study seeks to deal with this challenge by conducting a cradle-to-grave LCA of three benzene-contaminated groundwater remediation strategies at an operational industrial site in northeastern China: (1) vertical barriers (VB), (2) pump-and-treat (PT), and (3) a novel nature-based solution (NBS) leveraging phytoremediation with integrated biomass valorization. Results reveal that the baseline NBS scenario (2.63 × 10⁴ kg CO₂-eq, excluding biomass valorization) reduces life cycle greenhouse gas (GHG) emissions by three orders of magnitude compared to traditional VB (1.01 × 10⁷ kg CO₂-eq) and PT (1.44 × 10⁷ kg CO₂-eq) scenarios, showcasing its remarkable sustainability potential. Process-specific optimization pathways, particularly enhanced biomass utilization and carbon storage strategies, further lower GHG emissions to achieve net-positive carbon impacts (−180 kg CO₂-eq/m³ fiber), thus amplifying green sustainability. The LCA also identified critical process contributors for each of these remediation alternatives and proposed targeted optimization strategies to further minimize environmental burdens across life cycle stages. Overall, by bridging material innovation, adaptive wellfield design, biomass valorization, and life cycle carbon quantification, this study provides scientific support, new perspectives and practical approaches to advance green and sustainable remediation for benzene-contaminated groundwater.