木质素衍生腐植酸制备与应用最新进展

Latest Development in the Fabrication and Use of Lignin-derived Humic Acid

腐殖质(HS)来源于自然腐烂的生物质。HS的主要产物是腐植酸、黄腐酸和腐黑物。HS是从自然资源(如煤、褐煤、森林和河流沉积物)中提取的。然而,从这些资源生产HS并不环保,可能会对生态系统造成影响。早期的理论认为HS可以通过酶促或有氧氧化从木质素转化而来;另一方面,木质素是纸浆和纸张生产过程的副产物,可通过商业获得,然而它仍未得到充分的利用。为了解决环境友好型HS生产和适应木质素增值化进程的挑战,木质素衍生HS的生产引起了人们的关注。目前木质素转化为类HS物质的化学改性途径有碱性有氧氧化、碱性氧化消化、氧化氨解等。本文全面论述了木质素转化为HS的基本要素。综述了天然HS和木质素衍生HS在土壤富集、肥料、废水处理、水净化、医药等领域的应用。此外,还介绍了目前木质素生产和利用HS所面临的挑战。

Humic substances(HS)are originated from naturally decaying biomass.The main products of HS are humic acids,fulvic acids,and humins.HS are extracted from natural origins(e.g.,coals,lignite,forest and river sediments).However,the production of HS from these resources is not environmentally friendly,potentially impacting ecological systems.Earlier theories claimed that the HS might be transformed from lignin by enzymatic or aerobic oxidation.On the other hand,lignin is a by-product of pulp and paper production processes and is available commercially.However,it is still under-utilized.To address the challenges of producing environmentally friendly HS and accommodating lignin in valorized processes,the production of lignin-derived HS has attracted attention.Currently,several chemical modification pathways can be followed to convert lignin into HS-like materials,such as alkaline aerobic oxidation,alkaline oxidative digestion,and oxidative ammonolysis of lignin.This review paper discusses the fundamental aspects of lignin transformation to HS comprehensively.The applications of natural HS and lignin-derived HS in various fields,such as soil enrichment,fertilizers,wastewater treatment,water decontamination,and medicines,were comprehensively discussed.Furthermore,the current challenges associated with the production and use of HS from lignin were described.