Synthesis of Layered Double Hydroxides Containing a Biodegradable Amino Acid Derivative and Their Application for Effective Removal of Cyanide from Industrial Wastes

Abstract

In this work, we report ultrasonic-assisted synthesis of layered double hydroxides (LDHs) containing biodegradable amino acid derivative, N,N′-(pyromellitoyl)-bis-L-isoleucine diacid, and their application for removal of cyanide ions from industrial wastes. The structure of the modified Mg−Al LDHs was studied using transmission electron microscopy (TEM), field-emission scanning electron microscopy (FE-SEM), FT-IR spectroscopy, and X-ray diffraction (XRD) techniques. The ability of the prepared LDHs for adsorption of cyanide ions from aqueous solutions was examined, and the effects of the different parameters were investigated. It was found that, under optimum conditions, the proposed LDHs adsorbent can remove 98.7% of cyanide content of the aqueous solution in less than 35 min. Compared to the recently reported methods for removal of cyanide; the proposed method has several advantages. First, the adsorbent particles (LDHs) are synthesized via an environmentally acceptable route; because water is used as solvent under ultrasonic irradiation. Second, cyanide ions are exchanged with biodegradable anions, thus the proposed method does not produce toxic waste. Third, the prepared adsorbent has high adsorption capacity and the fast adsorption kinetics, thus it can be used for lowering the concentration of cyanide in the wastes to below regulatory limits in practically acceptable times.

Precursor Preparation to Promote the Adsorption of Mg‐Al Layered Double Hydroxide

“…This typical structure gives the sample some interesting properties such as base catalysis, memory effect, ion‐exchange capability and adjustable element compositions. Much attention has been paid to possible applications in wide ranges of catalysis, ion exchange, medical processes, pharmacy, and nanocomposite syntheses . Syntheses of LDH materials have been widely investigated for preparing elastomer composites, adsorbents, and intercalated drugs .…”

“…Much attention has been paid to possible applications in wide ranges of catalysis, ion exchange, medical processes, pharmacy, and nanocomposite syntheses. [1][2][3][4][5][6][7] Syntheses of LDH materials have been widely investigated for preparing elastomer composites, 8 adsorbents, 9 and intercalated drugs. 10 The commonly used method for LDHs synthesis is the coprecipitation of metal salts from a mixed solution at constant pH in the presence of anionic species which is to be intercalated into the layers of LDHs.…”

Using Mg‐Al‐layered double hydroxide intercalated with chiral dicarboxylic acid for the reinforcement of isoleucine amino acid containing poly(amide‐imide)

“…The band around 447 cm −1 results from the lattice vibration of the hydroxide sheet and the broad band in the range of 3,200–3,700 cm −1 mainly from O–H groups of the hydroxide layers are observed. A broad band or shoulder is observed in all modified samples in the range 1,600–1,640 cm −1 , which may indicate the presence of H 2 O molecules as bending vibration appears in this region . The absorption bands at 2,930–3,100 cm −1 correspond to the ν asym and ν sym (C‐H) modes of CH 2 group in the chiral dicarboxylate molecules.…”

“…Figure shows the FTIR spectra of MgAl‐LDH‐ , modified LDH and l‐ isoleucine containing diacid. For neat LDH, the broad band in the range 3,200–3,700 cm −1 is because of the O–H stretching vibration of the metal hydroxide layer and interlayer water molecules . The band characteristic to metal‐oxygen bond stretching appears below 700 cm −1 .…”

Silica@layered double hydroxide core–shell hybrid materials

“…chloride, hydroxide, and carbonate) to large surfactants and proteins. [14][15][16][17] Owing to their flexibility in composition and echangeable interlayer anions, LDHs have found application in drug delivery, 1,[18][19][20] waste water treatment, [21][22][23][24] Michael addition, 11,25 oxidation, [26][27][28] and transesterification. [29][30][31] An important characteristic of LDHs is the dispersion of metal cations in the layers.…”