Recyclable NiO/sepiolite as adsorbent to remove organic dye and its regeneration

Shu Gao,Xiangfeng Lin,Dahua Wang,Zhi Huang,Chengyuan Su,Menglin Chen

doi:10.1038/s41598-022-06849-6

Shu Gao, Xiangfeng Lin + Show 4 more

Open Access

https://doi.org/10.1038/s41598-022-06849-6

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Journal: Scientific Reports	Publication Date: Feb 21, 2022
Citations: 8	License type: open-access

Affiliation: Guangxi Normal University

Abstract

In this study, the impregnation synthesis of NiO/sepiolite and its application for dye removal during wastewater treatment is introduced. The NiO/sepiolite materials act as an adsorbent/catalyst. It comprises a unique combination of adsorption and high-temperature gas flow regeneration (the NiO/sepiolite acts as a catalyst at this stage, using regeneration rate as evaluation index of catalytic activity of NiO/sepiolite) in a single unit, in which the NiO/sepiolite was regenerated and reused for the next round adsorption of dye. An aqueous solution of methylene blue was used to evaluate the adsorption and regeneration performance of the adsorbent/catalyst. The regeneration rate reached 74% when the reaction time and temperature were 7 min and 350 °C, respectively. The effects of the regeneration temperature and volume fraction of O2 on the regeneration rate were investigated. And the regeneration reaction kinetics was provided. The combination of adsorptive and catalytic properties in the NiO/sepiolite composites received interesting results for removing refractory biodegradable organic pollutants. This work provides new insights for the removal of dye from wastewater using Ni catalysts supported on natural low-cost clay.

Highlights

In this study, the impregnation synthesis of nickel oxide (NiO)/sepiolite and its application for dye removal during wastewater treatment is introduced
We can see that the amount load of NiO is 2.1032% from the XRF analysis, which is in agreement with the X-ray diffractometry (XRD) result that the signal of 2θ = 37.2° is not obvious
The methylene blue that adsorbed on the NiO/sepiolite was oxidized by oxygen with volume fractions of 21%, 50% and 99.5%, the gas flow rate was 6 L/min, and the temperature was maintained at 350 °C to record the TG data

Summary

Introduction

The impregnation synthesis of NiO/sepiolite and its application for dye removal during wastewater treatment is introduced. The adsorption of dye on the NiO/sepiolite and the subsequent high-temperature gas flow regeneration behavior are studied.

Results

Conclusion