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This study focused on the feasibility of using Fe 3 O 4 /graphene oxide (FGO) nanocomposites as heterogeneous catalysts for the advanced treatment of real industrial wastewater. FGO nanocomposites with different graphene oxide (GO) ratios were synthesized by co-precipitating iron salts onto GO sheets in basic solution. Characterization of the resulting material structures and functionalities was performed using a range of analytical techniques. A low GO loading afforded a good Fe 3 O 4 nanoparticle dispersibility and resulted in a higher Brunauer-Emmett-Teller surface area and pore volume. The FGO nanocomposites and pure Fe 3 O 4 were used to treat papermaking wastewater in a heterogeneous photo-Fenton process. The results suggested that the nanocomposite designated FGO1 (GO loading of 25 mg) exhibits a higher photocatalytic e ciency than other FGO nanocomposites and pure Fe 3 O 4 . A maximum chemical oxygen demand degradation e ciency of 89.6% was achieved in 80 min with 1.5 g.L − 1 FGO1 at pH 3. The degradation of different pollutants present in wastewater was evaluated with the aid of gas chromatography-mass spectrometry and 3D excitation-emission-matrix analysis. Inductively coupled plasma atomic emission spectroscopy and magnetic measurements con rmed that the FGO1 nanocomposites possess a low iron leachability and a high reusability. Thus, a comprehensive advanced treatment of real industrial wastewater using a magnetic FGO catalyst is demonstrated.

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This study focused on the feasibility of using Fe3O4/graphene oxide (FGO) nanocomposites as heterogeneous catalysts for the advanced treatment of real industrial wastewater. FGO nanocomposites with different graphene oxide (GO) ratios were synthesized by co-precipitating iron salts onto GO sheets in basic solution. Characterization of the resulting material structures and functionalities was performed using a range of analytical techniques. A low GO loading afforded a good Fe3O4 nanoparticle dispersibility and resulted in a higher Brunauer–Emmett–Teller surface area and pore volume. The FGO nanocomposites and pure Fe3O4 were used to treat papermaking wastewater in a heterogeneous photo-Fenton process. The results suggested that the nanocomposite designated FGO1 (GO loading of 25 mg) exhibits a higher photocatalytic efficiency than other FGO nanocomposites and pure Fe3O4. A maximum chemical oxygen demand degradation efficiency of 89.6% was achieved in 80 min with 1.5 g.L− 1 FGO1 at pH 3. The degradation of different pollutants present in wastewater was evaluated with the aid of gas chromatography–mass spectrometry and 3D excitation–emission-matrix analysis. Inductively coupled plasma atomic emission spectroscopy and magnetic measurements confirmed that the FGO1 nanocomposites possess a low iron leachability and a high reusability. Thus, a comprehensive advanced treatment of real industrial wastewater using a magnetic FGO catalyst is demonstrated.

The secondary treated effluents of pulp and paper mills contain high chemical oxygen demand (COD) that is associated with organic matter. Therefore, this study explores the adsorption of substances contributing to COD using CoFe2O4 and quartz sand-coated CoFe2O4 in batch and fixed-bed column experiments. X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller analysis, and X-ray photoelectron spectroscopy were used to characterize the adsorbents. The quartz sand-loaded CoFe2O4 exhibited a larger pore volume and average pore size. Batch experiments revealed that adsorption on CoFe2O4 closely fit the pseudo-second-order model. To explore the effects of bed depth, feed flow rate, and initial solution pH on the breakthrough characteristics of CoFe2O4-coated sand, fixed-bed column experiments were conducted, and the breakthrough curves were drawn from the ratio of influent COD concentration to effluent COD concentration. The breakthrough time decreased with an increase in the feed flow rate and initial pH but increased with the bed depth. According to the X-ray photoelectron spectroscopy analysis, CoFe2O4-coated sand showed excellent stability due to negligible leaching of metallic elements. These findings have important implications for the advanced treatment of industrial wastewater.