Permanganate (Mn(VII)) is a traditional reagent used for water purification, but it is mild to deal with refractory organic contaminants of emerging concern. There is great interest in combination with effective and low-cost biochar to improve reaction kinetics of Mn(VII). Until recently, it still unclear how biomass composition and carbon structure of biochar influence the Mn(VII) oxidation performance. Herein, we prepared a series of biochar via pyrolyzing different sources of biomass, and their introduction enhanced 24 % of Mn(VII) oxidation of diclofenac (DCF) to 47.3 %∼100 % within 20 min. Particularly, Mn(VII)/walnut shell biochar (SBC) system achieved the highest reaction rate constant of 0.3817 min