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http://hdl.handle.net/10773/31367
Title: | Water softening using graphene oxide/biopolymer hybrid nanomaterials |
Author: | Rocha, Luciana S. Nogueira, João Daniel-da-Silva, Ana Luísa Marques, Paula Fateixa, Sara Pereira, Eduarda Trindade, Tito |
Keywords: | Water hardness Graphene oxide Polysaccharide Softeners Water treatment |
Issue Date: | Feb-2021 |
Publisher: | Elsevier |
Abstract: | There is a growing interest in developing more environmentally friendly softeners for hardness reduction of water supplied for domestic consumption. This work focuses on exploring biopolymer-based softeners, through the surface modification of graphene oxide (GO) with the anionic biopolymer κ-carrageenan (GO-Si(κ)CRG). The performance of the modified GO to decrease the hardness of natural waters containing high levels of Ca2+ was assessed. The sorption efficiency was dependent on the initial Ca2+ concentration and on the sorbent dose, with 8–34% removal for GO and 21–100% for GO-Si(κ)CRG. The surface modification considerably improved the adsorptive efficiency and under certain experimental conditions, it was possible to convert very hard water (300 mg L−1 CaCO3) to soft water. Importantly, the performance was not affected by the presence of other ions typically found in natural bottled waters. The kinetics was well described by pseudo-first-order and diffusion models. The multi-linear nature observed in Boyd’s and Webber’s plots suggested that both film diffusion and pore diffusion controlled the sorption rate. The maximum Ca2+ sorption capacity at monolayer coverage of GO-Si(κ)CRG was 47.6 ± 3.2 mg g−1. The electrostatic attraction between sulfonate groups and calcium cations is likely to be the main mechanism involved in the sorption process of Ca2+ by GO-Si(κ)CRG. Overall, the results indicate good prospects for the development of a new class of softeners based on the GO modification described. |
Peer review: | yes |
URI: | http://hdl.handle.net/10773/31367 |
DOI: | 10.1016/j.jece.2021.105045 |
ISSN: | 2213-3437 |
Publisher Version: | https://www.sciencedirect.com/science/article/pii/S2213343721000233 |
Appears in Collections: | TEMA - Artigos CESAM - Artigos CICECO - Artigos DQ - Artigos REQUIMTE - Artigos |
Files in This Item:
File | Description | Size | Format | |
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Water-softening-using-graphene-oxide-biopolymer.pdf | 1.63 MB | Adobe PDF | View/Open | |
WaterSofteningSI.pdf | 358.88 kB | Adobe PDF | View/Open |
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