Elsevier

Intermetallics

Volume 129, February 2021, 107030
Intermetallics

Efficient degradation of orange II dye using Fe-based metallic glass powders prepared by commercial raw materials

https://doi.org/10.1016/j.intermet.2020.107030Get rights and content

Highlights

  • The MG powders show high efficiency for the degradation of azo dyes wastewater.

  • The spongy porosity and metastable properties of powders improve the degradability.

  • The MG powders possess the good long-term stability and great application prospect.

Abstract

An efficient, economical and reusable Fe-based metallic glass (MG) powders were prepared for degrading Orange II solution. The influence parameters such as initial pH, temperature, recycle times and initial Orange II concentration were investigated for the degradation efficiency. The experimental result shows that 98.6% degradation rate was achieved within 2 min using low dosage Fe–Si–B–P–C glassy powders at acidic pH value. In addition to the metastable properties of glassy powders, the excellent degradation performance can relate to the spongy porosity of powder surface appeared during degradation treatment. We also found that the degradation rate improved obviously with the increase of temperature or acid strength in solution. After recycle experiment of six times, the glassy powders still maintained high degradation efficiency to Orange II solution. This work will contribute to the development of cheap and high quality glassy powders with excellent ability to degrade azo dyes.

Introduction

Azo dyes are widely used in textiles, dyestuff and leather industries, and produce a lot of residual dyes in effluents. This has attracted major attention because it is a serious threat to the environment if discharged without sufficient degradation [[1], [2], [3], [4], [5]]. Various treatment technologies have been searched for the purification of azo dye-polluted water, such as the traditional physical, photochemical, and biological methods. The physical methods include flocculation and absorption [6,7], but they merely transfer the azo dye rather than degrading them [8]. The biotic degradation methods are fail when in the effluents containing a wide variety of chemicals and only suitable for degradation of some special toxic azo dyes [9,10]. Recently, the zero-valent iron (ZVI) has been extensively studied as reducing agent because it is cheap and eco-friendly for wastewater treatment. By this method, the azo bonds will be cleaved with the reductive transformation of azo dyes [[11], [12], [13]]. Also, some innovative approaches, for example nano zero-valent iron (NZVI) powders, have been developed to enhance the degradation efficiency of Azo dyes by increasing the specific surface area of ZVI [14]. However, these ZVI powders will be oxidized easily and lose the high reactivity when in contact with water, which make it only applicable to low pH values and need longer reaction time to achieve the desired effect [15]. One way that can improve the chemical stability of ZVI is by adding noble metals, which raises the cost of degradation treatment, thus limiting its wide application [16]. Therefore, it is necessary to search for the efficient and cheap materials for the degradation of azo dyes.

Long range disorder metallic glasses obtained by rapid quenching result in constituent atoms not residing at the thermodynamic equilibrium positions [[17], [18], [19]]. The metastable nature with higher Gibbs free energy brings many special chemical properties such as good catalytic and chemical properties, which is superior to crystal alloys of the same composition and make the metallic glasses become a new competitive and promising catalysts for wastewater treatment [[20], [21], [22], [23], [24], [25]].

In this paper, by mechanical milling of glassy ribbons, we prepared Fe76Si7.6B9.5P5C1.9 metallic glass powders without noble metal using industrial raw materials. The intrinsic brittleness of the Fe-based metallic glasses is beneficial to the fabrication of fine powders. Eventually, the Orange II azo dye solution was effectively degraded by the Fe76Si7.6B9.5P5C1.9 metallic glass powders. Meanwhile, the effect of some parameters such as initial pH, initial dye concentration and solution temperature on degradation efficiency was investigated in detail. It was found that the low-cost Fe-based metallic glass powders almost completely degraded the azo dyes with low dosage in 2 min at acidic pH value. Furthermore, the glassy powders can be recycled at least six times by magnetic separation without major loss of activity.

Section snippets

Experimental

Alloy ingot with the nominal composition of Fe76Si7.6B9.5P5C1.9 was produced by arc melting commercial pure raw materials under argon atmosphere. The glassy ribbons were prepared by the single copper roller melt-spining method. Thickness of 22 μm and width of 0.5 mm were determined by a micrometer caliper and a vernier caliper respectively. Fe76Si7.6B9.5P5C1.9 glassy powders were obtained by mechanical ball milling for 16 h at 300 r/min rounding speed under argon atmosphere. The ratio of ball

Result and discussions

The structure of the MG powders was examined by XRD as presented in Fig. 1 (a). The amorphous nature of the powders can be verified by the broad peak in the XRD pattern. Meanwhile, the amorphous nature of Fe–Si–B–P–C powders can also be maintained after reuse of six cycles for the degradation of Orange II shown in the figure. The distribution of particle size was shown in Fig. 1 (b), which indicated the diameter was in the range of 0.5–20 μm. The average diameter was estimated to be about

Conclusion

In summary, we prepared the Fe-based MG powders with cheap industrial raw materials. The MG powders showed high efficiency for the degradation of azo dyes wastewater, which can be attributed to the metastable properties of glassy powders and the spongy porosity of powder surface appeared during degradation treatment. The influence of some reaction parameters such as temperature, initial Orange II concentration and initial pH value on the degradation of Orange II has been investigated and the

CRediT authorship contribution statement

Huaijun Sun: Project administration, Methodology, Writing - review & editing, Formal analysis. Hao Zheng: Writing - original draft, Investigation. Xiaohong Yang: Revision, Data curation, Software.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

Financial support was provided by the Scientific Research Foundation from Jiyang College of Zhejiang Agriculture and Forestry University of China (Grant No. JY2017RC04 and RQ2020A02) and the National Natural Science Foundation of China (Grant No. 52071165 and 51771083).

References (32)

Cited by (0)

View full text