Removal of tetracycline by biochar synergistic with ferrate: Influencing mechanism on precursor biomass components.

Biochar can serve as an activator for potassium ferrate, significantly enhancing the treatment efficiency to antibiotics. However, the mechanism by which biochar activated potassium ferrate remained unclear, necessitating further investigation. Cellulose biochar (CBC) and lignin biochar (LBC) derived by two model compounds which were the highest proportion of content in biomass were adopted to be study object, to investigate the removal efficiency of tetracycline (TC) by ferrate synergetic with CBC and LBC, respectively for the first time, and thoroughly analyzed the adsorption and degradation processes within the reaction system. It is noteworthy that CBC contributed to this synergy primarily through the phenolic hydroxyl groups which facilitated the decomposition of ferrate and increase the generation of intermediate valence iron species, thereby improving removal rates. Whereas, LBC enhanced removal rates of TC mainly across its own adsorption capabilities. This also resulted in LBC manifesting excellent synergistic effects under various pH environments, while the CBC system was primarily suited for alkaline conditions. This study provided new theoretical support for the efficient utilization of ferrate in organic wastewater treatment and offered a novel perspective on the precise control of structure in the process of biochar material prepared by agricultural and forestry solid waste biomass.