Study of Biochar with Different Cellulose/Lignin Ratios for Organic Pollutant Removal in Water Through Fenton-like Catalysis Assisted with Adsorption

In the present study, cellulose and lignin with different weight ratios were mixed and pyrolyzed to prepare biochars for organic dye pollutant removal in water via Fenton-like catalysis. The results indicated that a higher cellulose content in a biomass precursor could result in a lower biochar yield with a lower carbon content in the biochar. Moreover, with the increase in cellulose content, the resulting biochar had a higher graphitization degree with higher levels of crystallinity, as well as a richer porosity. When using Rhodamine B (RhB) as the dye probe, the biochar derived from a higher cellulose/lignin ratio precursor exhibited better adsorptive performance. It was further found that the biochar could act as a Fenton-like catalyst to activate peroxydisulfate (PDS) and accelerate RhB removal via a degradation route, in which single oxygen (1O2) was identified as the active species. Therefore, the biochar/PDS catalytic system exhibited prominent RhB removal stability in various water matrices with a wide pH application range. This study develops a new approach to prepare biomass-derived biochar with high organic removal capacity via Fenton-like catalysis assisted with adsorption synergy.