Synthesis of zero-valent iron/biochar by carbothermal reduction from wood waste and iron mud for removing rhodamine B.

Chao Chen,Wenzhi Qi,Xuetao Zhu,Qin Liu,Jianguo Liu,Fan Wang,Chao Gen

doi:10.1007/s11356-021-13962-y

Chao Chen, Wenzhi Qi + Show 5 more

Open Access

https://doi.org/10.1007/s11356-021-13962-y

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Abstract

This study proposes a new process to synthesize zero-valent iron/biochar (Fe0-BC) by carbothermal reduction using wood waste and iron mud as raw materials under different temperature. The characterization results showed that the Fe0-BC synthesized at 1200 °C (Fe0-BC-1200) possessed favorable adsorption capacity with the specific surface area of 103.18 m2/g and that the zero-valent iron (Fe0) particles were uniformly dispersed on the biochar surface. The removal efficiency of rhodamine B (RB) was determined to evaluate the performance of the prepared Fe0-BC. Fe0-BC-1200 presented the best performance on RB removal, which mainly ascribes to that more Fe0 particles generated at higher temperature. The equilibrium adsorption capacity reached 49.93 mg/g when the initial RB concentration and the Fe0-BC-1200 dosage were 100 mg/L and 2 g/L, respectively, and the pseudo-second-order model was suitable to fit the removal experimental data. LCMC and XRD analyses revealed that the removal mechanism included the physical adsorption of biochar and the redox reaction of Fe0. Moreover, copper existing in the iron mud was also reduced to Cu0, which was beneficial to catalyze the oxidation of iron; the degradation of RB was promoted at the same time.

Highlights

This study proposes a new process to synthesize zero-valent iron/biochar (Fe0-BC) by carbothermal reduction using wood waste and iron mud as raw materials under different temperature
Copper existed in the iron mud was reduced to Cu0, which was beneficial to catalyze the oxidation of iron, the degradation of rhodamine B (RB) was promoted at the same time
Wood waste and iron sludge were used as carbon and iron sources, respectively, and a new process was proposed to synthesize the zero-valent iron/biochar (Fe0-BC) by carbothermal reduction under the condition of oxygen isolation

Summary

Introduction

This study proposes a new process to synthesize zero-valent iron/biochar (Fe0-BC) by carbothermal reduction using wood waste and iron mud as raw materials under different temperature. The application of biochar in wastewater has some problems, such as difficult separation and incomplete removal (Chen et al, 2011; Du et al, 2020) To overcome these shortcomings, many researchers loaded zero-valent iron (Fe0) on biochar surface to synthesize zero-valent iron/biochar (Fe0-BC). Iron mud is usually disposed by stacking, landfilling, or sending to steel plants as a raw material of iron-making in China (Liu et al, 2014). For sending to steel plant, iron mud can block the furnace because of its fine particle size, thereby seriously reducing the product quality and complicating the recycling process

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