Fe incorporated mesocellular foam as an effective and stable catalyst: Effect of Fe concentration on the characteristics and activity in Fenton-like oxidation of acid red B

Study on the treatment of simulated azo dye wastewater by a novel micro-electrolysis filler

A new type of iron-copper-carbon (Fe-Cu-C) ternary micro-electrolysis filler was prepared with a certain proportion of iron powder, activated carbon, bentonite, copper powder, etc. The effect of the new type of micro-electrolysis filler on the simulated methyl orange dye wastewater was studied. The effects of various operational parameters, such as reaction time, initial pH value, aeration rate, filler dose and reaction temperature, on the degradation rate of methyl orange were studied to determine the optimum treatment conditions, and the micro-electrolysis filler was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The experimental results show that the degradation rate of 220 mL of simulated dye wastewater with a concentration of 100 mg/L reached 93.41% ± 2.94% after 60 mL/min of aeration, with an initial pH = 2, a dose of 45 g and 125 minutes of reaction at room temperature. The new micro-electrolysis filler has a high degradation rate for methyl orange solution, which is attributed to the iron and activated carbon particles sintered into an integrated structure, which makes the iron and carbon difficult to separate and affects the galvanic cell reaction. The addition of copper also greatly increases the transmission efficiency of electrons, which promotes the reaction. In addition, the surface iron is consumed, the adjacent carbon is stripped layer by layer, and the new micro-electrolytic filler does not easily passivate and agglomerate during its use.

Heterogeneous Fenton-like discoloration of organic dyes catalyzed by porous schorl ceramisite

Due to the difficult separation of superfine schorl powder (SSP) from solution after being used, millimetre-scale porous schorl ceramisite (PSC) was obtained through solid-phase sintering method and used as a heterogeneous catalyst for Fenton-like discoloration of organic dyes. SSP and PSC were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The results demonstrated that both SSP and PSC were mainly composed of schorl and there existed large amounts of micropores on the surface of PSC. A series of control experiments indicated that PSC exhibited higher Fenton-like catalytic activity than SSP. Methylene blue (MB) discoloration in both PSC-H₂O₂ and SSP-H₂O₂ systems followed pseudo-first-order kinetics and the reaction rate constant k₁ obtained in PSC-H₂O₂ system was 3.23 times as large as the one in SSP-H₂O₂ system. Then, the process optimization of MB discoloration in heterogeneous Fenton-like reaction catalyzed by PSC was operated by central composite design under response surface methodology. Based on the model prediction, the optimum conditions for MB discoloration in this system were determined.