Zhou et al., in BiocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More, investigated the synergistic mechanism of urea and sodium carbonate during biochar modification and peroxymonosulfate (PMS) activation for wastewater decontamination. Biochar co-modified with urea and an alkaline substance exhibited superior performance in PMS activation for wastewater decontamination.

However, the mechanism underlying the synergistic relationship between urea and alkaline substance to functional groups and electronic structure of biochar during modification, and its impact on PMS activation pathway remains understudied. In this research, a modified biochar (NABC) was successfully synthesized via the one-pot pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More of a mixture of urea, Na2CO3, and corncob. The synergistic effect of urea and Na2CO3 during pyrolysis was elucidated using various characterizations. Urea provided N sources and small aromatic rings, while Na2CO3 promoted the conversion of pyridinic N to graphitic N and signified the degree of graphitization. Na2CO3 also facilitated the retention of -COOH. Thus, NABC was porous and contained rich graphitic N and -COOH, along with a high graphitization degree, endowing it with 5.2 times higher first-order kinetics than that of pristine biochar. Moreover, NABC shifted the PMS activation mechanism by inhibiting the formation of •OH and promoting generation of 1O2 and O2•– to degrade aniline. DFT calculations further confirmed that graphitic N and -COOH functioned as critical active sites, synergistically activating PMS.

This research provides a theoretical foundation for optimizing the co-modification of biochar for more efficient wastewater purification.  

SOURCE: Zhou, T., Zhu, S., Li, X., Wang, X., Huang, R., Dong, W., Zhao, Z., & Wang, H. (2025). Unraveling the synergistic mechanism of urea and sodium carbonate during biochar modification and peroxymonosulfate activation for wastewater decontamination. Biochar, 7(2), 35. https://doi.org/10.1007/s42773-025-00433-7