Synthesis of carbon microsphere-supported nano-zero-valent iron sulfide for enhanced removal of Cr(VI) and p-nitrophenol complex contamination in peroxymonosulfate system

Carbon microspheres supported sulfurized nano zero-valent iron (CMS@S-nFe0) was successfully prepared. The interaction impact of different dosages on the removal of Cr(VI) and p-nitrophenol (PNP) complex contamination was explored by response surface method (RSM). The results showed both the C group and Fe2+ on the surface of carbon microspheres could be used as activators of peroxymonosulfate (PMS) decomposition, and •OH and SO4•- could be produced to promote the oxidative degradation of PNP. Among them, SO4•- was the main reactive oxygen species. The presence of PNP could further promote the reduction of Cr(VI). Besides, loading nFe0 and FeS compounds on the carbon base could significantly reduce the production of free iron ions, which could effectively remove Cr(VI) and PNP from polluted water. In terms of treatment results, CMS@S- nFe0 was a promising material for wastewater treatment because of its excellent performance in adsorption of heavy metals and degradation of organic pollutants.