Efficient Removal of Heavy Metal Ions in Wastewater by Using a Novel Alginate-EDTA Hybrid Aerogel

Min Wang,Zhuqing Wang,Xiaohong Zhou,Shikun Li

doi:10.3390/app9030547

Min Wang, Zhuqing Wang + Show 2 more

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https://doi.org/10.3390/app9030547

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Journal: Applied sciences	Publication Date: Feb 6, 2019
Citations: 23	License type: CC BY 4.0

Affiliation: Anqing Normal University, University of Bremen

Abstract

In this study, we prepared a novel calcium alginate-disodium ethylenediaminetetraacetate dihydrate hybrid aerogel (Alg-EDTA) by chemical grafting and vacuum-freeze-drying to remove heavy metal ions from wastewater. Experimental results show that the as-prepared Alg-EDTA adsorbent has a high affinity for heavy metal ions, such as Cd2+, Pb2+, Cu2+, Cr3+, and Co2+, and can adsorb >85% of metal ions from the corresponding solution. Alg-EDTA also exhibits high selectivity toward Cd2+, and the maximum adsorption capacity for Cd2+ reached 177.3 mg/g, which exceeds the adsorption capacity of most reported Cd2+-adsorbents. Adsorbent regeneration can be achieved by a simple acid-washing process, and adsorption performance of Alg-EDTA remains stable after repeated use. All these findings indicate that Alg-EDTA has a promising prospect in the treatment of heavy metal ions wastewater.

Highlights

With the rapid development of industries such as mining, metallurgy, electroplating, and battery manufacture, many heavy metal ions are released into natural waters [1]
We have used vacuum-freeze-drying technology and chemical-grafting technology to prepare a series of calcium alginate and modified calcium alginate aerogels [4,5,6,7]
To confirm whether saltwas wassuccessfully successfully modified alginate, we determined thethe salt modifiedtotosodium sodium alginate, we determined the IR spectra of sodium alginate, ethylenediaminetetraacetate dihydrate (EDTA) salt, Alg-EDTA, and Alg-EDTA loaded with Cd2+

Summary

Introduction

With the rapid development of industries such as mining, metallurgy, electroplating, and battery manufacture, many heavy metal ions are released into natural waters [1]. We have used vacuum-freeze-drying technology and chemical-grafting technology to prepare a series of calcium alginate and modified calcium alginate aerogels [4,5,6,7]. These synthesized aerogels provide good selectivity and adsorption capacity for Pb2+ ions. The maximum adsorption capacity of the chitosan-modified calcium alginate aerogel for Pb2+ ion is up to 468.5 mg/g, which is higher than most of the reported Pb2+ -adsorbents [5]

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