Enhanced Arsenic Removal from Aqueous Solution by Fe/Mn-C Layered Double Hydroxide Composite

Abstract

A novel material named Fe/Mn-C layered double hydroxide composite (Fe/Mn-C-LDH) was synthesized to remove arsenic from an aqueous solution. The removal performance of the composite toward arsenic ions was studied through the batch experiments. The experiment results showed that Fe/Mn-C-LDH exhibited a high adsorption capacity of 46.47 mg/g for As(III) and 37.84 mg/g for As(V) at 318 K, respectively. In addition, the investigation of the release of Fe3+ and Mn2+ in the process of arsenic adsorption revealed that the Fe/Mn-C-LDH exhibited better stability than Fe/Mn-layer double hydroxide (Fe/Mn-LDH) with fewer Mn2+ and Fe3+ releasing under the same condition. The BET results showed that the specific surface area of Fe/Mn-C-LDH decreased after adsorption of As (III) and As (V). Furthermore, the Density Functional Theory (DFT) calculation results proved that the adsorbent combining arsenic by T-site to produce a better adsorption effect for arsenic. Possessing better stability and adsorption capacity, Fe/Mn-C-LDH could potentially serve as a perfect adsorbent for arsenic removal from an aqueous environment. It would provide a promising approach for removing heavy metal from the aquatic environment in the future.

Hydroxymethyl-Functionalized Polymer Nanospheres with a Hollow Mesopore Structure for Efficient Acteoside Adsorption

“…Table S6 presents the results of calculations made about the thermodynamic characteristics of the adsorption of ACT onto HPN-2. The negative Δ G values at all temperatures showed the spontaneity of the ACT adsorption process onto HPN-2 . The Δ H > 0 of the ACT adsorption process demonstrated that the adsorption onto HPN-2 was an endothermic process .…”

“…The negative ΔG values at all temperatures showed the spontaneity of the ACT adsorption process onto HPN-2. 47 The ΔH > 0 of the ACT adsorption process demonstrated that the adsorption onto HPN-2 was an endothermic process. 48 Furthermore, the positive values of ΔS indicated the increasing randomness and the good binding affinity of HPN-2 for the adsorption of ACT.…”

Adsorption-Desorption Surface Bindings, Kinetics, and Mass Transfer Behavior of Thermally and Chemically Treated Great Millet Husk towards Cr(VI) Removal from Synthetic Wastewater

“…(S7)-(S10) mentioned in Table S4 (supplementary material). The negative estimation of ∆ G listed in Table 4 indicates the spontaneous adsorption of Cr(VI) onto the adsorbent and thermodynamic feasibility of the adsorption process [44]. A positive value of ∆ H indicates that the process is endothermic in nature.…”

Removal of Toxic Metals from Water by Nanocomposites through Advanced Remediation Processes and Photocatalytic Oxidation

“…The Fe/Mn-C-LDH was more stable than the Fe/Mn-layer twofold hydroxide (Fe/Mn-LDH), with less Mn 2+ and Fe 3+ being released under the same conditions. According to the BET data, the adsorption of arsenic(III) and arsenic(V) onto Fe-Mn-C-LDH reduced its specific surface area [108]. Among both composites, HNTs/C/Fe 3 O 4 showed the best performance because of their unique heterojunction.…”