Adsorption and Reduction of Aqueous Cr by FeS-Modified Fe-Al Layered Double Hydroxide

Shuangshuang Zhang,Wenhui Zhang,Yazhen Wan

doi:10.3390/su14010021

Shuangshuang Zhang, Wenhui Zhang + Show 1 more

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https://doi.org/10.3390/su14010021

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Journal: Sustainability	Publication Date: Dec 21, 2021
Citations: 5	License type: CC BY 4.0

Affiliation: Zhengzhou University

Abstract

To remedy the widespread chromium (Cr) pollution in the environment, this study mainly used the ultrasonic-assisted co-precipitation and precipitation methods to prepare FeS-modified Fe-Al-layered double hydroxide (FeS/LDH) composite material. The experimental results showed that FeS/LDH has higher removal efficiency of Cr in aqueous solution and stronger anti-interference ability than unmodified LDH. Under the same reaction conditions, the removal efficiency of total Cr(Cr(T)) using LDH was 34.85%, and the removal efficiency of Cr(VI) was 46.76%. For FeS/LDH, the removal efficiency of Cr(T) and Cr(VI) reached 99.57% and 100%, respectively. The restoration of Cr(T) and Cr(VI) by FeS/LDH satisfied the Langmuir adsorption isotherm. The maximum adsorption capacity of Cr(T) and Cr(VI) achieved 102.9 mg/g and 147.7 mg/g. The efficient removal of Cr by FeS/LDH was mainly based on the triple synergistic effect of anion exchange between Cr(VI) and interlayer anions, redox of Cr(VI) with Fe2+ and S2−, and co-precipitation of Fe3+ and Cr3+.

Highlights

Heavy metal pollution is a major pollution problem that threatens people’s health [1,2].Since heavy metal ions cannot be biodegraded, they can accumulate in an organism along with transfer to the ecosystem and have an indelible impact on human health [3,4].Chromium (Cr) is a common heavy metal pollutant in soil and water that has been identified as a human carcinogen by the International Agency for Research on Cancer [5]
FeS/layered double hydroxide (LDH) was mainly based on the triple synergistic effect of anion exchange between Cr(VI) and interlayer anions, redox of Cr(VI) with Fe2+ and S2−, and co-precipitation of Fe3+ and Cr3+
These are the characteristic peaks of LDH; in addition, there is a peak of SO bond at 1060 cm−1 and a peak at 2950 cm−1 caused by SH-stretching vibration on FeS/LDH3 [31,35,37]

Summary

Introduction

Heavy metal pollution is a major pollution problem that threatens people’s health [1,2].Since heavy metal ions cannot be biodegraded, they can accumulate in an organism along with transfer to the ecosystem and have an indelible impact on human health [3,4].Chromium (Cr) is a common heavy metal pollutant in soil and water that has been identified as a human carcinogen by the International Agency for Research on Cancer [5]. Heavy metal pollution is a major pollution problem that threatens people’s health [1,2]. Since heavy metal ions cannot be biodegraded, they can accumulate in an organism along with transfer to the ecosystem and have an indelible impact on human health [3,4]. Chromium (Cr) is a common heavy metal pollutant in soil and water that has been identified as a human carcinogen by the International Agency for Research on Cancer [5]. Exists in the form of Cr2 O3 , which can form precipitates or complexes into other substances and stably exists in water or soil [6]. The toxicity of Cr(VI) is 100 times greater than Cr(III) [8,9]

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Conclusion