Heterogeneous fenton oxidation of methylene blue with Fe-impregnated biochar catalyst

Abstract

Fe-impregnated biochar (Fe-BC) as high-efficiency heterogeneous Fenton catalyst was synthesized and evaluated in detail for its catalytic activity, stability and reusability under various conditions. The optimal conditions for the Fenton oxidation of methylene blue (MB) as model dye were determined as 0.075 g/L H 2 O 2 , 0.5 g/L Fe-BC for 0.1 g/L MB, which resulted in optimum Dye:Fe cat :H 2 O 2 ratio of 1:5:0.75 (on g/L basis) or [Dye]:[Fe total ]:[H 2 O 2 ] molar ratio of 1:6.2:7.0 respectively. The effective degradation of MB was identified over a wider pH range, and even after four consecutive runs Fe-BC maintained above 95% MB removal rate within 3 min of treatment with low Fe release, indicating strong stability and reusability. Under the optimum Dye:Fe cat :H 2 O 2 (g/L) condition at initial pH 4, the Fe-BC achieved 99.9% removal efficiency of MB within 3 min in heterogeneous Fenton reaction (HEFR) with much less H 2 O 2 concentration and low catalyst dosage, demonstrating its efficiency and cost-effectiveness compared to other Fenton reaction catalysts. The removal velocity of MB showed two rate steps: a fast first stage followed by a slow stage with the rate in the order of H 2 O 2 /Fe-BC ⋙ H 2 O 2 /biochar > biochar > H 2 O 2. Overall, the developed Fe-BC is more economical with strong stability and recyclability for use in HEFR for treating recalcitrant pollutants.

Catalytic Reaction Intensification by a Novel Cryogenic Auxiliary Synthesized Fe-PAN Membrane

“…The oxide layer might be regenerated on the surface of the NZVI, as shown in eqs –, , increasing the resistance of electron transport between the NZVI and the reactants. Thus, the reaction rate decreased …”

“…The oxide layer might be regenerated on the surface of the NZVI, as shown in eqs –, , increasing the resistance of electron transport between the NZVI and the reactants. Thus, the reaction rate decreased 4 F e 0 + 3 O 2 + 2 H 2 normalO → 4 γ ‐ F e O O H 8 γ ‐ normalF normale normalO normalO normalH + F e 0 → 3 F e 3 O 4 + 4 H 2 normalO 2 γ ‐ normalF normale normalO normalO normalH + F e 2 + → normalF e 3 O 4 + 2 H + 4 F e 3 O 4 + O 2 + 6 H 2 normalO → 12 γ ‐ F …”

“…With the rapid development of modern industry, the heterogeneous catalytic reaction has attracted the attention of researchers. However, due to the existence of an interface, it is hard for heterogeneous catalysts to fully contact the reactants, resulting in great restriction of reaction mass transfer . As a key factor of chemical engineering, restricted reaction mass transfer leads to low catalytic efficiency, side reactions, high material and energy consumption, and serious pollution. , In order to strengthen the heterogeneous catalytic reaction, it is urgent to develop novel catalysts with excellent mass transfer properties.…”

The degradation of methylene blue by microcubes catalyst -Fe2O3 via heterogenous Fenton process

“…However, the most challenge in design such heterogeneous catalyst is the low efficiency and stability as the nano catalyst tends to agglomerate leading to a reduce of catalyst surface area. Therefore, a development of catalyst with both high efficiency and stability is one of the major issues today [6].…”

A new neodymium complex on renewable magnetic biochar nanoparticles as an environmentally friendly, recyclable and efficient nanocatalyst in the homoselective synthesis of tetrazoles

“…and other inorganic compounds have been reported as catalyst supports in numerous articles. [1][2][3][4][5][6] Meanwhile, modern chemistry and green chemistry emphasize the use of renewable materials, so that one of the principles of green chemistry is waste recycling. [7][8][9][10][11][12][13] Therefore, in order to recycle agricultural waste, in this work we synthesized biochar nanoparticles from pyrolysis of chicken manure and used them as a recyclable support for the synthesis of a reusable and heterogeneous catalyst.…”