A Study on the Interaction Between Dissolved Organic Matter and Heavy Metals Based on the Derwent and IncoPat Patent Databases: A Bibliometric Analysis

Heavy metal pollution remediation faces bottlenecks such as low efficiency of physical methods, secondary pollution risks from chemical approaches, and scaling limitations of microbial techniques. Dissolved organic matter (DOM), leveraging its green resource potential and high-efficiency chelation properties, has emerged as a core innovation direction in pollution remediation. Addressing existing patent metrics research issues such as single-database bias, fragmented classification systems, and insufficient policy-technology coupling analysis, this study employs a synergistic analysis of the Derwent and IncoPat databases to systematically reveal the technological innovation landscape in DOM-heavy metal interactions. Covering the period from 2004 to 2024, a differentiated strategy centered on “DOM-heavy metal interactions” was implemented. After processing steps including family-based deduplication, classification calibration, and citation normalization, analysis was conducted within a three-dimensional framework of “time-region-technology.” Results indicate: Chinese patents account for 46.6% and 55.0% of the two databases respectively, establishing global dominance. IncoPat exhibits an “early lead-platform fluctuation” pattern, while Derwent shows “late explosive growth.” Precise policy-technology coupling forms a closed-loop system of policy tools, R&D investment, and technological output. Technological evolution shows significant divergence: Derwent focuses on foundational digital innovation, while IncoPat emphasizes engineering applications. Core patents enabled domain innovation through “foundational technology-cross-domain adaptation.” The landmark patent CN101168852A established the “solid waste resource utilization-process controllability-material functionalization” paradigm, validating its engineering value. This study corrected single-database biases, clarified global versus local technological evolution differences and core driving mechanisms, and provides support for interdisciplinary integration, engineering transformation, and policy optimization.