Adsorption of perchlorate from water using quaternary ammonium‐functionalized chitosan beads

Abstract

Perchlorate, one of the persistent inorganic pollutants, was efficiently removed from water using quaternary ammonium‐functionalized cross‐linked chitosan beads (QACB). This synthesized bead was found to be efficient in terms of perchlorate removal capacity, 100% regeneration of used beads (using HCl or NaCl) and selectivity in the presence of coanions, namely, chloride, sulfate, carbonate, and nitrate. QACB removes perchlorate by exchange of chloride ions. QACB was able to remove >95% perchlorate from brackish water. Batch studies were carried out in order to optimize the condition for maximum perchlorate removal. The perchlorate removal capacity of QACB from 1,000 mg/L of aqueous solutions was 153.0 mg/g. The outcome of pH variation studies indicated that QACB is able to remove perchlorate in the pH ranges of 2–11. Equilibrium isotherm data of adsorption of perchlorate at temperature 303, 313, and 323 K were well fitted to the linear Freundlich, Langmuir, and Dubinin–Radushkevich isotherm models. The adsorption kinetics data were best described by the pseudo‐second‐order kinetic model. FTIR was used to confirm the interaction of perchlorate with QACB. A small‐scale column test was carried out to evaluate the capacity of QACB for removing perchlorate from brackish water.

Synthesis of MgAl-LDH@ZIF-8 composites by in situ growth method for highly efficient phosphate removal

“…MgAl-LDH and MgAl-LDH@ZIF-8 showed a broad absorption peak at 3458 cm À1 , which could be attributed to the stretching vibration of interlayer O-H of MgAl-LDH particles and O-H of interlayer water molecules. 37 The absorption peak at 1360 cm À1 is caused by the stretching vibration of the interlayer anion NO 3 À . The absorption peaks in the range of 400-700 cm À1 (445, 544, and 660 cm À1 ) belong to the stretching vibration peaks of Al-O and Mg-O.…”

Influence of 2‐hydroxypropyltrimethyl ammonium chloride chitosan on sedimentation and volume change behavior of cohesive soil sediments

“…37,38 Quaternary ammonium (QA)-based materials introduce the QA groups to the Nitrogen-atoms position, resulting in a stable cationic charge. [39][40][41] HACC has good solubility and stable cationic charges, promoting the strong adsorption effect. The performance research of QA-functionalized Chitosan to solve soil problems is significant.…”

“…For example, carboxymethyl chitosan has a significant anti‐swelling effect on Na‐bentonite, and 2‐hydroxypropyltrimethyl ammonium chloride chitosan (HACC) also significantly controls the expansion of Na‐ bentonite 37,38 . Quaternary ammonium (QA)‐based materials introduce the QA groups to the Nitrogen‐atoms position, resulting in a stable cationic charge 39–41 . HACC has good solubility and stable cationic charges, promoting the strong adsorption effect.…”