The graph above shows that functionalized biochar has a regression coefficient (R 2 ) value of 0.975, which is a good result. Thus, the pseudo-second order model fits this data the best. The graph above shows that functionalized biochar has a regression coefficient (R2) value of 0.0086, which is a good result. Thus, the pseudo-second order model fits this data the best. This kinetic model made it very evident that the study's results justify the pseudosecond order kinetic model well.