Heterogeneous activation of persulfate by metal and non-metal catalyst for the degradation of sulfamethoxazole: A review

Carbon materials in persulfate-based advanced oxidation processes: The roles and construction of active sites

Herein, an electrochemical (EC) system was applied as “co-catalyst” to enhance the activation of peroxymonosulfate (EC/Fe(III)/PMS) for efficient Sulfamethoxazole (SMX) degradation. The cathodic reduction reaction can facilitate electron transfer to Fe(III) and trigger the sustainable Fe(III)/Fe(II) redox cycle. Unexpectedly, in addition to hydroxyl radical ( • OH) and sulfate radical (SO 4 •− ), non-radicals mechanism including singlet oxygen ( 1 O 2 ) and Fe(IV) were also found involved in EC/Fe(III)/PMS system. The degradation of SMX in EC/Fe(III)/PMS system was accomplished by the collaboration of radicals and non-radicals oxidation. The generation routes and mechanisms of involved reactive oxygen species (ROS) were explored. The relative contributions of • OH, SO 4 •− , and nonradical species for the degradation of SMX were calculated to 4.75 %, 25.31 %, and 69.94 %, respectively. Besides, multiple degradation pathways of SMX were proposed by identifying the formed byproducts. The EC/Fe(III)/PMS process could efficiently degrade SMX under the influence of co-existing ions and inactivate pathogens in the wastewater. • Electrochemical system was used as a “co-catalyst” to promote the Fe(III)/Fe(II) redox cycle. • SMX is effectively degraded with a weak electrical current consumption in EC/Fe(III)/PMS system. • EC/Fe(III)/PMS system is mainly a non-radical pathway dominated by 1 O 2 and Fe(IV). • EC/Fe(III)/PMS system demonstrated the ability to simultaneously eliminate contaminants and pathogens. 

Sustainable Fe(III)/Fe(II) cycles triggered by co-catalyst of weak electrical current in Fe(III)/peroxymonosulfate system: Collaboration of radical and non-radical mechanisms

The efficient activation and utilization of peroxymonosulfate (PMS) in PMS-based advanced oxidation processes is a high-priority target for the removal of organic contaminants. This work introduces a water vortex-driven piezoelectric effect from few-odd-layered MoS2 into the PMS activation to remove benzotriazole (BTR) and other organic contaminants from the water. Approximately 91.1% of BTR can be removed by the MoS2 piezo-activated PMS process with a reaction rate constant of 0.428 min-1, which is 2.09 times faster than the sum of the individual MoS2, water vortex, and piezocatalysis rates. Meanwhile, the PMS utilization efficiency reached 0.0147 in the water vortex-driven piezo-activation system, which is 3.97 times that of the sum from the vortex/PMS and MoS2/PMS systems. These results demonstrate that the presence of MoS2 under a water vortex can trigger a piezoelectric potential and generate abundant free electrons to activate PMS to generate various active species for degradation of organic contaminants. 

https://doi.org/10.1016/j.ese.2022.100165

Enhanced utilization efficiency of peroxymonosulfate via water vortex-driven piezo-activation for removing organic contaminants from water

Fe3C/Fe decorated N-doped magnetic carbon materials (denoted as Fe3C/Fe@N-C-x) were successfully fabricated via facile one-pot calcination of MIL-88B(Fe) with a green precursor of melamine. Benefiting from the co-existence of sp2-hybridized C–π moieties, oxygen-containing groups (CO and O–CO), N-doping species and ferreous nanoparticles (FNPs), the as-obtained Fe3C/Fe@N-C-9 exhibited excellent activation of peroxymonosulfate (PMS) for ultrafast elimination of various emerging organic contaminants with high mineralization capacities. Inspired by the unique nanotube morphology and encapsulation of FNPs, the Fe3C/Fe@N-C-9 possessed trace Fe leaching and can be magnetically separated for an easy recycling. Combining with competitive radical scavenging tests, electron spin resonance (ESR), electrochemical analysis and in-situ Raman spectra, the singlet oxygen (1O2) and electron-transfer can be accounted for the organic pollutant removal. Because of that, the Fe3C/Fe@N-C-9 exhibited good resistance to inorganic anions and natural organic matters (NOMs). It was fascinating that Fe3C/Fe@N-C-9 achieved satisfactory treatment efficiency for real pharmaceutical wastewater. 

Ultrafast degradation of emerging organic pollutants via activation of peroxymonosulfate over Fe3C/Fe@N-C-x: Singlet oxygen evolution and electron-transfer mechanisms

Yanshan Wang

Papers

Tunable active sites on biogas digestate derived biochar for sulfanilamide degradation by peroxymonosulfate activation.

Co/N co-doped carbonized wood sponge with 3D porous framework for efficient peroxymonosulfate activation: Performance and internal mechanism

Active sites decoration on sewage sludge-red mud complex biochar for persulfate activation to degrade sulfanilamide.

Hydrothermal carbonization of garden waste by pretreatment with anaerobic digestion to improve hydrohcar performance and energy recovery.