Persulfate activation by swine bone char-derived hierarchical porous carbon: Multiple mechanism system for organic pollutant degradation in aqueous media

Recent years, application of biochar in catalysis field has attracted increasing attention for it is an effective, inexpensive and environment friendly methods to solve the environmental issues. The aim of this work is to apply bone char (BBC) into persulfate (PS) activation system and achieve efficient 2,4-dichlorophenol (2,4-DCP) degradation. This work first applied de-fatted swine bone as the biochar precursor. The as-prepared BBC has considerable high surface area (1024.34m(2)/g) and wide porous distribution. Especially the hierarchical porous structure is supposed to accelerate the electrons transfer in this catalytic process. The results showed that over 85% of 2, 4-DCP can be removed in 30 min and almost 100% of 2, 4-DCP can be completely degraded in 2 h. Further research found that 2, 4-DCP was eliminated by both radical and non-radical pathway, and radical pathway dominated the catalytic process in BBC/PS system. (OH)-O-center dot, SO4 center dot-, O-2(center dot-) and O-1(2) all contributed to this system, among which the (OH)-O-center dot played the most significant role. Liner Sweep Voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) were taken to verify the non-radical pathway did exist in this system. Owing to the existence of multiple mechanisms, the BBC/PS system remained highly efficient in real surface water and it had remarkable adaptability to various environment conditions. This research commits to proposing a novel strategy for green remediation of contaminated water.