Optimization of a textile dye degradation in a recirculating fluidized-bed reactor using magnetite/S2O82- process

Advancements of the Fluidized Bed Fenton (FBF) Technology for wastewater treatment: Mechanism, mass and heat transfer

Fluidized Bed Fenton (FBF) technology, a fusion of the Fenton method and fluidized bed reactor, has emerged as a superior alternative to conventional Fenton technology for treating organic industrial wastewater. This innovative approach has garnered significant attention from researchers in recent years. While earlier studies primarily focused on pollutant degradation in simulated wastewater and catalyst development, there has been a growing interest in examining the alterations in mass or heat transfer performance attributed to fluidized beds. This paper explores the factors that contribute to the effectiveness of Fluidized Bed Fenton technology in efficiently degrading various challenging organic pollutants, while also reducing iron sludge production and expanding the applicable pH range, through an analysis of reaction kinetics. Meanwhile, combined with the related work of fluid dynamics, the research related to mass and heat transfer inside the reactor of Fluidized Bed Fenton technology is summarized, and it is proposed that the use of computers to establish a suitable model of Fluidized Bed Fenton and solve it with the assistance of computational fluid dynamics (CFD) and other software will help to further explore the process of mass and heat transfer inside the fluidized bed, which will provide the basis for the future of the Fluidized Bed Fenton from the laboratory to the actual industrial application.

Synthesis of Nano-Fe@NdFeB/AC magnetic catalytic particle electrodes and application in the degradation of 2,4,6-trichlorophenol by electro-assisted peroxydisulfate process

The coupling of electrolysis and the peroxydisulfate (PDS) activation was selected in this study to degrade solution-phase 2,4,6-trichlorophenol (TCP). To enhance the PDS activation efficiency and catalytic recycling ratio, a novel magnetic activator, nano iron coated on neodymium iron boron/activated carbon nanocomposite (Nano-Fe@NdFeB/AC), was synthesized and utilized as catalytic particle electrodes. To increase the mass transfer ability, a novel magnetic internal circulation electrolytic reactor (MICE) was established. The results indicated that globular Fe, with sizes ranging from 25 nm to 300 nm, is present on the surface of the catalyst. This catalyst has sufficient magnetism to be separated by the magnetic separation method and its specific saturation magnetization and residual magnetization were 1.48 and 0.26 emu/g, respectively. At the optimal condition of [pH]₀= 9.0, [Na₂S₂O₈]₀= 2.0 mmol/L, [Nano-Fe@NdFeB/AC]₀= 5.0 g/L and I = 50 mA, the TOC percentage of removal could reach 84% after 30 min of reaction. The TCP mineralization follows pseudo-first-order kinetics. The intermediate products of 2,6-dichloro-2,5-cyclohexadiene-1,4-dione, Tetrachloro-hydroquinone, and 2,3,5,6-tetrachloro-p-benzoquinone were found during the reaction. TCP mineralization was confirmed to have a hybrid mechanism involving reductive dechlorination with Fe, •OH addition oxidation and electron capture by SO•₄ ^-. This study provides a new method for the treatment of degradation-resistant pollutants.