Catalytic Degradation of Bisphenol A in Water by Poplar Wood Powder Waste Derived Biochar via Peroxymonosulfate Activation

A series of biochar materials was prepared through pyrolyzing poplar wood powder waste under different pyrolyzing temperatures, which were afterwards characterized in detail. Then, the poplar powder biochar (PPB) was used to degrade bisphenol A (BPA) in water via activating peroxymonosulfate (PMS). The results indicate that the activation efficiency of the prepared PPB was correlated with its surface functional groups, which were regulated by its pyrolyzing temperature. Specifically, the biochar pyrolyzed at 600 °C (PPB-600) exhibited the optimal BPA removal activity, in which 0.5 g/L of PPB-600 could remove 0.02 mM of BPA within 120 min. From the results of scavenging tests, ESR analysis and probe pollutant degradation tests, it was inferred that the BPA was degraded by non-radical singlet oxygen in the PPB/PMS system. Since PPB consumed its surface oxygen functional groups and structural defects to activate PMS, the catalytic performance of PPB was gradually reduced after several cycles. This study can provide new insight for the design and preparation of metal-free biochar catalysts from waste wood precursor for the highly-efficient removal of refractory organic pollutants in water.