Removal of p-nitrophenol using persulfate activated by biochars prepared from different biomass materials

Three biochars from wheat straw(WSC), chicken manure(CMC) and rice husk(RHC) were prepared as persulfate(PS) activators for p -nitropheol(PNP) removal. RHC exhibitted the best adsorption performance, followed by WSC and CMC, which was consistant with the surface area value. PS addition further promoted the PNP removal, indicating that a synergistic effect existed in the biochar/PS combined system. The composition and textual properties of biochar had a significant effect on the reactivity of activator and the function groups containing oxgygen or nitrogen might play important roles in the reaction. WSC could perform efficiently over a pH range from 4.4 to 10.4. The decrease in activation performance in cycle experiments was possiblely related to the loss of oxgygen-containing groups.