Chauhan D, Kumar A, Warkar SG. Modified polymeric hydrogels for the detection of Zn
2+ in
E. coli bacterial cells and Zn
2+, Cd
2+ and Hg
2+ in industrial effluents.
ENVIRONMENTAL TECHNOLOGY 2022;
43:3600-3607. [PMID:
33977856 DOI:
10.1080/09593330.2021.1928294]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 04/30/2021] [Indexed: 06/12/2023]
Abstract
The article focusses on exploring the real-time application of meta-benziporphodimethene (m-BPDM) embedded polyacrylamide/carboxymethylguargum (PAM/CMG) hydrogel. The hydrogel-based sensor is highly selective for Zn2+, Cd2+ and Hg2+ with no significant response to other competitive cations including Na+, K+, Ca2+, Cr3+, Pb2+, Mg2+, Mn2+, Co2+, Cu2+ in aqueous medium. Initially, the stability of the hydrogel has been examined at different pH conditions. The sensitivity of the hydrogel was found to be 0.5, 1, and 2 ppm in 1, 2 and 3 h for Hg2+, Zn2+, and Cd2+, respectively, at pH 6. The sensor exhibits colour change from red to bluish-green with Zn2+, Cd2+ and Hg2+ in water over other ions. The modified hydrogel matrix displayed a unique naked eye turn-on colorimetric sensor selectivity for Zn2+, Cd2+ and Hg2+ ions in the aqueous solutions of Escherichia coli (E. coli) bacterial cells and industrial effluents. During the detection process, the zinc metal ions released because of cell lysis bind with hydrogel, in the former. The binding of Zn2+ causes the change in the colour of hydrogel from red to bluish-green, which was visually detected. The m-BPDM does not leach out and is stable in the hydrogel matrix. The sensing of Zn2+, Cd2+ and Hg2+ was achieved by directly adding hydrogel into industrial effluent without any pretreatment of effluent. The quantitative determination of Zn2+, Cd2+ and Hg2+ in industrial effluent was performed by the atomic absorption spectroscopy technique just to confirm the results obtained with the hydrogel.
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