Highly effective oxidation of roxarsone by ferrate and simultaneous arsenic removal with in situ formed ferric nanoparticles

Front. Environ. Sci. Eng.

Shao

Qiao

et al. 2020

The past two decades have witnessed the rapid development and wide application of Fe(VI) in the field of water de-contamination because of its environmentally benign character. Fe(VI) has been mainly applied as a highly efficient oxidant/disinfectant for the selective elimination of contaminants. The in situ generated iron(III) (hydr)oxides with the function of adsorption/coagulation can further increase the removal of contaminants by Fe(VI) in some cases. Because of the limitations of Fe(VI) per se, various modified methods have been developed to improve the performance of Fe(VI) oxidation technology. Based on the published literature, this paper summarized the current views on the intrinsic properties of Fe(VI) with the emphasis on the self-decay mechanism of Fe(VI). The applications of Fe (VI) as a sole oxidant for decomposing organic contaminants rich in electron-donating moieties, as a bi-functional reagent (both oxidant and coagulant) for eliminating some special contaminants, and as a disinfectant for inactivating microorganisms were systematically summarized. Moreover, the difficulties in synthesizing and preserving Fe(VI), which limits the large-scale application of Fe (VI), and the potential formation of toxic byproducts during Fe(VI) application were presented. This paper also systematically reviewed the important nodes in developing methods to improve the performance of Fe(VI) as oxidant or disinfectant in the past two decades, and proposed the future research needs for the development of Fe(VI) technologies.

Section: Organophosphorus and Organoarsenic Compoundsmentioning

confidence: 99%

Section: Organophosphorus and Organoarsenic Compoundsmentioning

confidence: 99%

Application of Fe(VI) in abating contaminants in water: State of art and knowledge gaps

Front. Environ. Sci. Eng.

Shao

Qiao

et al. 2020

“…14,15,21 Therefore, compared with the pure adsorption, the combination of adsorption and chemical oxidation is recognized as a more promising strategy because the removal efficiency of total arsenic could be improved after the oxidative transformation of p-ASA. 22,23 For example, both Fenton reaction and ferrate are effective for the oxidation of p-ASA and subsequent removal of the total arsenic species via the in situ flocculation of the newly formed ferric ions. 23−25 However, the non-recyclability of the Fe-based reagents makes the processes costly for application.…”

Section: ■ Introductionmentioning

confidence: 99%

Interface-Promoted Direct Oxidation of p-Arsanilic Acid and Removal of Total Arsenic by the Coupling of Peroxymonosulfate and Mn-Fe-Mixed Oxide

Huang

Mei

et al. 2021

Environ. Sci. Technol.

As one of the extensively used feed additives in livestock and poultry breeding, p-arsanilic acid (p-ASA) has become an organoarsenic pollutant with great concern. For the efficient removal of p-ASA from water, the combination of chemical oxidation and adsorption is recognized as a promising process. Herein, hollow/porous Mn–Fe-mixed oxide (MnFeO) nanocubes were synthesized and used in coupling with peroxymonosulfate (PMS) to oxidize p-ASA and remove the total arsenic (As). Under acidic conditions, both p-ASA and total As could be completely removed in the PMS/MnFeO process and the overall performance was substantially better than that of the Mn/Fe monometallic system. More importantly, an interface-promoted direct oxidation mechanism was found in the p-ASA-involved PMS/MnFeO system. Rather than activate PMS to generate reactive oxygen species (i.e., SO4 ·–, ·OH, and 1O2), the MnFeO nanocubes first adsorbed p-ASA to form a ligand–oxide interface, which improved the oxidation of the adsorbed p-ASA by PMS and ultimately enhanced the removal of the total As. Such a direct oxidation process achieved selective oxidation of p-ASA and avoidance of severe interference from the commonly present constituents in real water samples. After facile elution with dilute alkali solution, the used MnFeO nanocubes exhibited superior recyclability in the repeated p-ASA removal experiments. Therefore, this work provides a promising approach for efficient abatement of phenylarsenical-caused water pollution based on the PMS/MnFeO oxidation process.

“…[ 1 ] Arsenic pollution mainly results from the discharge of industrial production, agricultural production, natural volcanic eruption, and some natural phenomena. [ 2 ] In most arsenic‐contaminated groundwater, arsenic concentrations range from 0.5 to 2.5 mg·l −1 . [ 3, 4 ] In some industrial wastewater, it can reach more than 100 mg·l −1 .…”

Section: Introductionmentioning

confidence: 99%

“…[ 11, 12 ] Among these methods, adsorption is one of the most promising methods because of its high efficiency, low cost, and simple operation. [ 12, 13 ] However, traditional adsorbents such as activated carbons, goethite, carbon nanotubes, and iron and aluminum oxides [ 2, 7, 11, 12 ] did not possess the adequate adsorption capacity. Therefore, it is of great significance to synthesize new adsorbents with high efficiency and high adsorption capacity for removing organic arsenics from the environment.…”

Section: Introductionmentioning

confidence: 99%

A new one‐dimensional coordination polymer synthesized from zinc and guanazole: Superior capture of organic arsenics

Zhang

et al. 2020

Applied Organom Chemis

Organic arsenic compounds in the environment are a global threat to human health. This threat has created the urgency to develop highly efficient adsorbents with both high adsorption capacity and versatile removal of different arsenic compounds. A novel 1D zinc(II) coordination polymer, formulated as Zn2(datrz)2(bpy)Cl2 (BUC‐70) (datrz = guanazole, bpy = 4,4′‐bipyridine), was successfully synthesized through slow evaporation at room temperature. BUC‐70 exhibited an excellent adsorption capacity toward p‐arsanilic acid (p‐ASA) and roxarsone (ROX) in water, which could be ascribed to As–O–Zn bonding interactions and strong hydrogen‐bonding interactions between the organic arsenics and BUC‐70. The maximum adsorption capacities toward p‐ASA and ROX were 738 and 937 mg·g−1, respectively. BUC‐70 was effective in the removal of p‐ASA and ROX at low concentrations (<5 mg·l−1) from the simulated p‐ASA and ROX wastewater. Furthermore, the as‐synthesized BUC‐70 exhibited good adsorption property toward p‐ASA and ROX in wastewater simulated by lake water and tap water. After adsorptive treatment using BUC‐70, the concentrations of both p‐ASA and ROX were lower than the required concentrations of the drinking water standard of the World Health Organization and the surface water standard of China. Continuous‐flow, fixed‐bed column experiments were performed using BUC‐70 loaded on cotton as packing material to explore the potential large‐scale application.