Highly efficient activation of peroxymonosulfate by cobalt ferrite anchored in P-doped activated carbon for degradation of 2,4-D: Adsorption and electron transfer mechanism

Xuetao Liang; Yujie Zhao; Jing Liu; Zhilin Yang; Qi Yang

doi:10.1016/j.jcis.2023.03.181

Highly efficient activation of peroxymonosulfate by cobalt ferrite anchored in P-doped activated carbon for degradation of 2,4-D: Adsorption and electron transfer mechanism

J Colloid Interface Sci. 2023 Jul 15:642:757-770. doi: 10.1016/j.jcis.2023.03.181. Epub 2023 Apr 5.

Authors

Xuetao Liang¹, Yujie Zhao¹, Jing Liu¹, Zhilin Yang², Qi Yang³

Affiliations

¹ Key Laboratory of Groundwater Circulation and Environmental Evolution (China University of Geosciences (Beijing)), Ministry of Education, Beijing 100083, China; China University of Geosciences (Beijing), College of Water Resources and Environment, Beijing 100083, China.
² Department of Biological and Agricultural Engineering, Texas A&M University, USA.
³ Key Laboratory of Groundwater Circulation and Environmental Evolution (China University of Geosciences (Beijing)), Ministry of Education, Beijing 100083, China; China University of Geosciences (Beijing), College of Water Resources and Environment, Beijing 100083, China. Electronic address: yq@cugb.edu.cn.

PMID: 37043936
DOI: 10.1016/j.jcis.2023.03.181

Abstract

The dispersing effect of carbon materials on nanoparticles can enhance the full exposure of their active sites. Herein, phosphorus (P)-doped activated carbon-supported trace cobalt ferrite composites (P-CoFe@BC_X) were achieved by two-step pyrolysis for efficient peroxymonosulfate (PMS) activation and water pollution remediation. The removal efficiency of 2,4-dichlorophenoxyacetic acid (2,4-D) was optimized by adjusting the coupling ratio of carbon substrate and cobalt ferrite. P-CoFe@BC₅/PMS oxidation system (0.10 g L^-1, 0.50 mM) eliminated 98.3% of 2,4-D (20.0 mg L^-1) within 60 min at unadjusted pH. The constructed adsorption enrichment and oxidative degradation pathways are highly efficient in utilizing reactive oxygen species (ROS), and the dual tracks of free and non-free radicals achieve the rapid degradation of 2,4-D. P-doped activated carbon acts as an electron shuttle to accelerate electron transfer between active sites and enhances the adsorption efficiency of 2,4-D and PMS onto the composites. In addition, the P-CoFe@BC₅/PMS oxidation system still exhibited strong 2,4-D removal performance at a wide pH range of 2.0-10.0. The inhibitory effect of environmental components was related to their concentration, such as chloride, bicarbonate, sulfate and humic acid. Density functional theory calculations show that ROS tends to attack the CO bond on the 2,4-D branch chain, and the degradation products show lower biological toxicity. Hence, the constructed cobalt ferrite anchored P-doped activated carbon activated PMS system has great potential in treating organic wastewater.

Keywords: Adsorption enrichment; Efficient degradation; Electron transfer; Pesticides; Phosphorus-doped activated carbon.