Magnetic nanocomposite adsorbents for abatement of arsenic species from water and wastewater

Humic Acid Glazed Magnetite Material for the Adsorptive Desulfurization of Model Fuel

Impact of climate change that stems from gaseous emissions require sustainable materials to eliminate sulfur. This study involves the modification of humic acid with magnetite nanoparticles (Fe₃O₄ NPs) by a microwave-assisted synthesis of an absorbent with reasonable pore volume and diameter for elimination of thiophenic compounds from fuel. The magnetic nano adsorbent designated Fe3O4@HA was characterized using advanced spectroscopic techniques, while their structure and morphology were analyzed through DLS, XPS, XRD, FT-IR, TGA, FESEM-EDX, VSM, and BET-N2 techniques. These findings indicated that the synthesized magnetic nano adsorbent (Fe3O4@HA) has appropriate oxygen functionalities with a specific surface area of 335 m2 g-1 and a mesoporous structure with a pore diameter of 9 nm. The adsorption capacity for sulfur was determined to be 62.73 mg g-1. The kinetic and isotherm models, coupled with thermodynamic characteristics, confirmed that the adsorption of sulfur onto the adsorbent was spontaneous, exothermic, and followed pseudo-first-order kinetics. The adsorbent material demonstrated reusability for sulfur adsorption for up to six cycles. The economic and environmental advantages of the preparation process provide humic acid modified with magnetite nanoparticles (Fe₃O₄ NPs) as an interesting candidate for real-world applications.

Magnetic biochar as a revolutionizing approach for diverse dye pollutants elimination: A comprehensive review

The term "biomass" encompasses all substances found in the natural world that were once alive or derived from living organisms or their byproducts. These substances consist of organic molecules containing hydrogen, typically oxygen, frequently nitrogen, and small amounts of heavy, alkaline earth and alkali metals. Magnetic biochar refers to a type of material derived from biomass that has been magnetized typically by adding magnetic components such as magnetic iron oxides to display magnetic properties. These materials are extensively applicable in widespread areas like environmental remediation and catalysis. The magnetic properties of these compounds made them ideal for practical applications through their easy separation from a reaction mixture or environmental sample by applying a magnetic field. With the evolving global strategy focused on protecting the planet and moving towards a circular, cost-effective economy, natural compounds, and biomass have become particularly important in the field of biochemistry. The current research explores a comparative analysis of the versatility and potential of biomass for eliminating dyes as a sustainable, economical, easy, compatible, and biodegradable method. The elimination study focused on the removal of various dyes as pollutants. Various operational parameters which influenced the dye removal process were also discussed. Furthermore, the research explained, in detail, adsorption kinetic models, types of isotherms, and desorption properties of magnetic biochar adsorbents. This comprehensive review offers an advanced framework for the effective use of magnetic biochar, removing dyes from textile wastewater.

Adsorption Behavior of Organoarsenicals over MnFe2O4-Graphene Hybrid Nanocomposite: The Role of Organoarsenic Chemical Structures

As a kind of emerging contaminant, organoarsenic compounds have drawn wide concern because of their considerable solubilities in water, and the highly toxic inorganic arsenic species formed during their biotic and abiotic degradation in the natural environment. Thus, the effective removal and studying of the adsorption mechanism of organoarsenic compounds are of significant urgency. In this work, MnFe2O4 and MnFe2O4/graphene were prepared through a facile solvothermal method. From the results of the Transmission Electron Microscope (TEM) characterization, it can be found that MnFe2O4 nanoparticles were uniformly distributed on the surface of the graphene. And the specific surface area of the MnFe2O4/graphene was about 146.39 m2 g-1, much higher than that of the MnFe2O4 (86.15 m2 g-1). The interactions between organoarsenic compounds and adsorbents were conducted to study their adsorption behavior and mechanism. The maximum adsorption capacities of MnFe2O4/graphene towards p-arsanilic acid (p-ASA) and roxarsone (ROX) were calculated to be 22.75 and 30.59 mg g-1. Additionally, the ionic strength, negative ions, and humus were introduced to investigate the adsorption performance of organoarsenic compounds. Electrostatic adsorption and surface complexation are the primary adsorption mechanisms on account of X-ray photoelectron spectroscopy (XPS) and the Fourier-transform infrared spectroscopy (FT-IR) analysis. This research extends the knowledge into studying the interaction between organoarsenic species and hybrid nanomaterials in the natural environment.