Aluminum Substituted Cobalt Ferrite (Co−Al−Fe) Nano Adsorbent for Arsenic Adsorption in Aqueous Systems and Detailed Redox Behavior Study with XPS

Abstract

Arsenic [As(III) and As(V)] adsorption on aluminum substituted cobalt ferrite (Co-Al-Fe) ternary metal oxide adsorbent is reported by means of qualitative and quantitative spectroscopy tools. IR and Raman active signals were observed around 810-920 cm band indicate different As-OH and As-O stretching vibrations on to the adsorbent. The adsorption behavior of arsenic (III and V) onto these adsorbents is studied as a function of contact time, different concentrations, and pH conditions. The kinetics study on adsorption were performed to understand nature of adsorption which supports the Pseudo Second Order (PSO) model. The adsorption isotherms study indicates Freundlich type of adsorption. The maximum adsorption capacity of Co-Al-Fe adsorbent is observed around 130 and 76 mg g for As(III) and As(V) systems, respectively. Detailed XPS study of As 3d, Fe 2p, Co 2p, and O 1s spectra has been reported in explaining the redox behavior and ligand exchange reactions in supporting arsenic adsorption mechanism.

Fe3O4-Functionalized Boron Nitride Nanosheets as Novel Adsorbents for Removal of Arsenic(III) from Contaminated Water

“…Moreover, the survey and narrow spectra of As 3d in Figure confirms the presence of As­(III) in the adsorbed sample. The broad peak of As 3d depicts the presence of As­(III) and As­(V) at 43.20 and 44.6 eV, respectively. , The presence of As­(V) in the adsorbed sample is attributed to the oxidation of As­(III) during the adsorption of As­(III) on the BNNS-Fe 3 O 4 nanocomposite …”

Defective Bismuth Oxide as Effective Adsorbent for Arsenic Removal from Water and Wastewater

“…Bi 2 O 3 could be easy tailored through surface modifications both during and after its synthesis [ 26 , 52 , 53 ]. This property is very attractive for electrochemical applications but implies unneglectable consequences during contaminant adsorption in real groundwater and wastewater environments.…”

“…3 eV and 528.1 eV. Curiously, the signals of adsorbed As(V) and As(III) were both composed of two components centered at 44.7 eV and 43.0 eV, corresponding to As(V) and As(III), respectively [ 53 ]. The redox of arsenic compounds during adsorption process is generally due to electrochemical active sites as in the case of Fe(II) or Mn related compounds [ 55 , 56 ], but in the case of Bi 2 O 3 could be imputable to oxidative power of Bi(V) sites embedded into Bi 2 O 3 [ 57 ] leading to oxidation of As(V).…”

Designing bimetallic zeolitic imidazolate frameworks (ZIFs) for aqueous catalysis: Co/Zn-ZIF-8 as a cyclic-durable catalyst for hydrogen peroxide oxidative decomposition of organic dyes in water

“…34,42,43 This depiction conrms that cobalt ions should have a different coordination environment, [44][45][46] which subsequently allows consecutive redox electron transfer. 45,47,48 In addition, the presence of a mixed metal system, such as the present case (Zn/Co), rises the metal-heterogeneity mode of the mixed valence system that should enhance the redox activity a character that is essential for catalytic reactions. 49,50 Fig.…”