Peroxymonosulfate Activation by Fe–Co–O-Codoped Graphite Carbon Nitride for Degradation of Sulfamethoxazole

Abstract

Graphite carbon nitride (g-C 3 N 4 ) has a stable structure but poor catalytic capability for activating peroxymonosulfate (PMS). In this study, the codoping of g-C 3 N 4 with bimetallic oxides (iron and cobalt) and oxygen was investigated to enhance its catalytic capability. The results showed that iron, cobalt, and oxygen codoped g-C 3 N 4 (Fe−Co−O−g-C 3 N 4 ) was successfully prepared, which was capable of completely degrading sulfamethoxazole (SMX) (0.04 mM) within 30 min, with a reaction rate of 0.085 min −1 , indicating the superior catalytic activity of Fe−Co−O−g-C 3 N 4 . The mineralization efficiency of SMX was 22.1%. Sulfate radicals and singlet oxygen were detected during the process of PMS activation. However, the role that singlet oxygen played in degrading SMX was not obvious. Surface-bound reactive species and sulfate radicals were responsible for SMX degradation, in which sulfate radicals contributed to 46.6% of SMX degradation. The superior catalytic activity was due to the synergistic effect of metal oxides and O−g-C 3 N 4 , in which O−g-C 3 N 4 could act as a carrier and an activator as well as an electron mediator to promote the conversion of Fe(III) to Fe(II) and Co(III) to Co(II). Four main steps of SMX degradation were proposed, including direct oxidation of SMX, bond fission of N−C, bond fission of N−S, and bond fission of S−C. The effect of the pH, temperature, PMS concentration, chloridion, bicarbonate, and humic acids on SMX degradation was investigated. Cycling experiments demonstrated the good stability of Fe−Co−O−g-C 3 N 4 . This study first reported the preparation of bimetallic oxide and oxygen codoped g-C 3 N 4 , which was an effective PMS activator for degradation of toxic organic pollutants.

Harnessing Paenarthrobacter ureafaciens YL1 and Pseudomonas koreensis YL2 Interactions to Improve Degradation of Sulfamethoxazole

“…Biological treatment uses microbial interaction to remove SMX, which is currently the most promising processing method [ 10 ]. To overcome the persistent toxicity and the high environmental mobility of SMX, various removal technologies have been reported, including biological treatment [ 11 , 12 , 13 , 14 ], adsorption [ 15 , 16 ], advanced oxidation [ 17 , 18 , 19 , 20 ], and electrochemical oxidation [ 21 , 22 ]. By comparison, biological treatment technologies have been widely used for their low treatment cost and environmental friendliness, which mostly rely on the metabolism of microbes [ 23 ].…”

Advanced Oxidation Processes Based on Sulfate Radicals for Wastewater Treatment: Research Trends

“…SR-AOPs have generated an increasing interest in the field of WW treatment due to their versatility, high oxidation potential and efficiency in the disinfection and degradation of persistent environmental pollutants and pathogenic load [7,[46][47][48][49].…”

Oxygen vacancy enhances the catalytic activity of trimetallic oxide catalysts for efficient peroxymonosulfate activation

“…17 Typically, cobalt (Co) was considered as the most effective transition metal for PMS activation, while the trimetallic spinel oxides containing Co were widely applied for electrodes or electrocatalysts. [18][19][20] Though, there are reports about the application of them in SR-AOPs and synergistic mechanisms among different metals have been found, 17,21 such catalysts still showed some shortcomings, such as low degradation efficiency under alkaline pH conditions or unavoidable secondary pollution. Recently, introducing defects such as dislocation or edge/ armchair sites, 22 anion/cation vacancy 23 and lattice defects 24 into catalysts has become a hot topic due to its merits in improving catalytic performance.…”