In:
Clay Minerals, Mineralogical Society, Vol. 56, No. 3 ( 2021-09), p. 169-177
Abstract:
Hierarchical layered double hydroxide (HLDH) was synthesized by using sodium dodecyl sulfate (SDS) as a soft-template agent for the removal of two charged organic dyes (i.e. methylene blue (MB; cationic dye) and methyl orange (MO; anionic dye)). The experimental results based on response surface methodology (RSM) demonstrated distinct removal behaviours of HLDH towards these two dyes: (1) the maximum capacity was 416.7 mg g –1 for MO and 58.7 mg g –1 for MB at 25°C; (2) the increase in temperature could enhance MO removal significantly, whereas it had a negligible effect on the MB treatment process; and (3) rapid removal of MB (5 min) compared to MO (480 min) was observed. In addition, the removal process for both dyes was pH-independent. Multiple characterization techniques further revealed the removal mechanisms, demonstrating that SDS played a significant role in the removal of both dyes; that is, MO replaced SDS to be intercalated into the HLDH interlayer via anion exchange. MB could influence the –SO 3 group of SDS, resulting in it modifying the electrodensity of SDS. It could then be further combined with an SDS anion (DS – ) via hydrophobic and electrostatic interactions to form DS-MB monolayers. This work not only provides an efficient capture agent for charged dyes, but also offers a deep insight into the underlying removal mechanism.
Type of Medium:
Online Resource
ISSN:
0009-8558
,
1471-8030
Language:
English
Publisher:
Mineralogical Society
Publication Date:
2021
detail.hit.zdb_id:
2036186-5
detail.hit.zdb_id:
961059-5
SSG:
13
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