Efficient activation of persulfate by Nickel-supported cherry core biochar composite for removal of bisphenol A.

In this study, low-cost and easily obtained biochar was chosen to prepare nickel-modified biochar materials (Ni/BC) through a one-step activation pyrolysis method. Characterization with X-ray diffraction, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy proved the existence of Ni and NiO nanocrystals in Ni/BC catalyst. The optimal Ni/BC exhibited excellent peroxymonosulfate (PMS) and peroxydisulfate (PDS) activation efficiency toward bisphenol A (BPA) degradation. The Ni/BC (0.03 g) reacted with 1.0 g L PMS or PDS could completely remove 20 mg L BPA in 10 min with the first-order kinetic constants (k) of 0.322 min (PMS) and 0.336 min (PDS). More importantly, the composite has better structural and functional attributes for the BPA degradation with universal applicability at wide pH and temperature range, proving as a better degradation mediator with high adaptation for numerous organic pollutants. Catalytic activity decreased slightly even after 4 cycles. Based on the quenching experiment and electron paramagnetic resonance, it was found that SO, •OH and O were the dominant active species in BPA degradation process. Therefore, this work not only supplies a promising catalyst for the removal of organic contaminants, but also is beneficial for the further development of alternative catalysts for sulfate radical based advanced oxidation processes.