Removal of Evans Blue by using Nickel‐Iron Layered Double Hydroxide (LDH) Nanoparticles: Effect of Hydrothermal Treatment Temperature on Textural Properties and Dye Adsorption

Abstract

Summary: The use of low‐cost adsorbent has been investigated as a replacement for the current expensive methods of removing dyes from wastewater. The sorption of acid dye (Evans Blue) from aqueous effluents onto anionic clays (hydrotalcite‐like) has been studied. Hydrotalcite may be an effective adsorbent of organic molecules due to its hydrophobic nature and the accessibility of its interlayer region. Ni/Fe layered double hydroxide (LDH), with a molar ratio of 3, were synthesised by coprecipitation followed by hydrothermal treatment at different temperatures (85, 100 and 140 °C) for 4 days. The materials were characterised by X‐ray powder diffraction (XRD), infrared spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2 adsorption‐desorption (BET). The diffractograms and FT‐IR spectroscopy of the fresh materials showed that the hydrotalcite is present in all samples. The XRD pattern obtained was typical of a hydrotalcite, where the interlayer anion is CO, XRD and Infrared spectroscopy complemented each other by showing that with treatment the degree of order increased regardless of the type of treatment. Furthermore, it was shown that aging at increased temperature and pressure increased crystallinity. TEM showed that crystal size increased with aging temperature, so that growth occurred on the edges resulting in the formation of hexagonal plate shaped hydrotalcite crystals. The surface area decreased with increasing the hydrothermal treatment temperature. The effects of various parameters such as hydrothermal treatment temperature, crystallite size, contact time and calcination on the extent of adsorption were investigated. The studies of the removal efficiency of the reactive textile dye: Evans Blue (Direct Blue 53) by NiFeCO3 HDLs showed that the effect of hydrothermal treatment temperature on adsorption increases with aging temperature. The Evans Blue (EB) removal percent increased with increasing contact time. Above the 70%, 50% and 20% of EB adsorption occurred in the first 2 min for HDL‐140, HDL‐100 and HDL‐85°C respectively. Furthermore, it was found that the calcined materials are much more effective than the original LDH in removing Evans Bleu dye from an aqueous solution.

Layered Double Hydroxide–Carbon Dot Composite: High-Performance Adsorbent for Removal of Anionic Organic Dye

“…6−8 The inherent structure feature allows LDH to become promising adsorbents to capture a range of anionic pollutants in aqueous solutions. 9−12 In general, three different mechanisms of LDH have been proposed to control the removal of contaminants from aqueous solutions, namely electrostatic attraction, 13,14 ion exchange, 15−17 and van der Waals force. 18 In addition, hydrogen bonding interactions are formed between hydroxyl groups of LDH and the nitrogen or oxygen-containing groups from adsorbates.…”

Ni–Al layered double hydroxides modified with citrate, malate, and tartrate: Preparation by coprecipitation and uptake of Cu2+ from aqueous solution

“…; and x is the M 3 þ /(M 2 þ þM 3 þ ) molar ratio (0.20%x%0.33) [1]. For conservation and remediation of water environments, LDHs and calcined LDHs have received attention for application to the removal of inorganic and organic anions such as terephthalate, benzoate, 4-methyl-benzoate, 2,4-dichlorophenoxyacetate, fluoride, chromate, bromide, and dyes from aqueous solutions [2][3][4][5][6][7][8][9][10].…”

Adsorption of reactive dyes from aqueous solutions by layered double hydroxides

“…The application of layered double hydroxides to the removal of dyes has been reported: i.e. indigo carmine dye,15 acid dyes like Green Bezanyl‐F2B,16 Evans Blue,17 C.I. Acid Blue 9,18 benzopurpurine 4B,19 or a basic dye 20.…”