Abiotic humification of biomass wastes for production of artificial humic acids: A concise review

Humification process is a major carbon sequestration strategy that can be enhanced using many biotic and abiotic catalysts. Artificial humic acids (AHAs) can be synthesized through a abiotic humification process, where certain catalysts containing metal oxides, such as manganese, iron, aluminum, or silicon minerals, catalyze the transformation of precursor compounds into humic molecules. AHAs have an advantage over natural-sourced humic acids (NHAs) in that their structural properties which can be controlled by adjusting the reaction conditions, including the type and amount of starting materials (lignocellulose composition, species of precursors, phenolic pollutants, etc.), pH, temperature, and type and dosage of catalysts and oxidants. While most research has centered on biotic humification pathways, there has been little exploration of abiotic humification pathways. This research will provide a concise review of the latest findings on the production of AHAs from lignocellulosic waste using abiotic humification pathways, along with the their reaction mechanisms. Understanding and optimizing abiotic humification can significantly contribute to more resilient agricultural practices, increased crop productivity, and enhanced environmental stewardship, paving the way for a more sustainable future in agriculture.

Keywords:

Artificial humic acids , Abiotic humification , Humic precursors , Reaction mechanism , Oxidation