Fe3O4 hollow nanospheres on graphene oxide as an efficient heterogeneous photo-Fenton catalyst for the advanced treatment of biotreated papermaking effluent.

Yecan Peng,Yangliu Du,Shuangfei Wang,Guirong Ye,Lingyu Zeng,Jiawen Hao,Jinghong Zhou

doi:10.1007/s11356-021-13458-9

Abstract

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 coprecipitating iron salts onto GO sheets in basic solution. The 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.

Highlights

Pulp and paper (P&P) production requires enormous amounts of fresh water and generates large quantities of heavily polluted effluents (Svensson and Berntsson 2014)
The removal efficiencies at pH 5, 7, and 9 were 41.3, 37.6, and 38.9%, respectively. These results indicated that the Fe3O4/graphene oxide (FGO) catalyst could be used under neutral conditions, and so can be employed in the advanced treatment of actual industrial wastewater containing organic pollutants
A maximum COD degradation efficiency of 89.6% was achieved after 80 min with 1.5 g.L− 1 FGO1 at pH 3

Summary

Introduction

Pulp and paper (P&P) production requires enormous amounts of fresh water and generates large quantities of heavily polluted effluents (Svensson and Berntsson 2014). Conventional P&P treatment processes (biological and physiochemical methods), including activated sludge processes, aerated lagoons, and biological reactors, have limited application in the case of refractory organic pollutants. These biologically treated effluents still contain many complex structural compounds, such as lignin and its derivatives (Elnakar and Buchanan 2019; Grotzner et al 2018; Toczylowska-Maminska 2017). To satisfy harsher environmental regulations and to avoid secondary wastewater pollution, it is necessary to search for environmentally friendly and efficient techniques for P&P industry wastewater treatment (Marques et al 2017; Sridhar et al 2011) In this context, the combination of biological and chemical treatment is an effective method to remove nonbiodegradable and toxic substances from industrial wastewater (Abedinzadeh et al 2018; Wang et al 2012)

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