Wastewater Treatment Using Novel Magnetic Nanosponges

Fe3O4@SiO2@NiAl-LDH microspheres implication in separation, kinetic and structural properties of phenylalanine dehydrogenase

Fe3O4@SiO2@NiAl-LDH three-components microsphere contains a Fe3O4@SiO2 magnetic core and a layered double hydroxide with nickel cation provide the binding ability to (His)-tagged-protein and exhibits high performance in protein separation and purification. The morphology and chemistry of the synthesized Fe3O4@SiO2@NiAl-LDH microspheres were characterized by energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), vibrating sample magnetometer (VSM), Dynamic light scattering (DLS). Purified enzyme was assesed with SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis and intrinsic fluorescence spectroscopy. In this study, the separation of phenylalanine dehydrogenase (PheDH) by Fe3O4@SiO2@NiAl -LDH was performed and the effect of microsphere was investigated on the kinetic and structural properties of PheDH. After purification, kinetic parameters such as Km, Vmax, Kcat, kcat/Km, optimum temperature, thermal stability, and and activation energy were evaluated and compared according to the mentioned methods. The interaction between the enzyme and the microsphere displayed a high performance in protein binding capacity. The results also revealed that the kinetic parameters of the enzyme changed in a dose-dependent manner in the presence of a microsphere. Moreover, the results of intrinsic fluorescence and Circular Dichroism (CD) confirmed the structural changes of the protein in the interaction with the microsphere.

Application of Bioelectrochemical Systems and Anaerobic Additives in Wastewater Treatment: A Conceptual Review

The interspecies electron transfer (IET) between microbes and archaea is the key to how the anaerobic digestion process performs. However, renewable energy technology that utilizes the application of a bioelectrochemical system together with anaerobic additives such as magnetite-nanoparticles can promote both direct interspecies electron transfer (DIET) as well as indirect interspecies electron transfer (IIET). This has several advantages, including higher removal of toxic pollutants present in municipal wastewater, higher biomass to renewable energy conversion, and greater electrochemical efficiencies. This review explores the synergistic influence of bioelectrochemical systems and anaerobic additives on the anaerobic digestion of complex substrates such as sewage sludge. The review discussions present the mechanisms and limitations of the conventional anaerobic digestion process. In addition, the applicability of additives in syntrophic, metabolic, catalytic, enzymatic, and cation exchange activities of the anaerobic digestion process are highlighted. The synergistic effect of bio-additives and operational factors of the bioelectrochemical system is explored. It is elucidated that a bioelectrochemical system coupled with nanomaterial additives can increase biogas-methane potential compared to anaerobic digestion. Therefore, the prospects of a bioelectrochemical system for wastewater require research attention.

Synthesis and Characterization of Functional Magnetic Nanomaterials

Nanoscale materials have grabbed the attention of researchers from a fundamental and application point of view for over a century [...]

Nanosponges for Water Treatment: Progress and Challenges

Nanosponges have shown promising capabilities for efficient removal of organic/inorganic pollutants from water based on absorption/adsorption and disinfection processes. The application of nanosponges (especially cyclodextrin-based nanosponges) can be considered a cost-effective strategy with minimal energy and time requirements in comparison to other routinely deployed water treatment modalities. These polymers with unique physicochemical properties, architectures, and highly cross-linked three-dimensional networks need to be further explored for removing pollutants with simultaneous eliminations of microbial contaminants from wastewater. Additionally, the surface functionalization of these nanosponges utilizing magnetic, titanium dioxide, and silver nanomaterials can significantly improve their properties for water remediation purposes, although nanosponges altered with carbon nanotubes and metallic nanomaterials/nanocatalysts for water treatment appliances are barely explored. Notably, crucial factors such as adsorbent type/dosage, contact time, competing ions, adsorption isotherm models, kinetics, thermodynamics, and reaction/experimental conditions (e.g., molar ratios, temperature, and pH) are important aspects affecting the adsorption and removal of pollutants using nanosponges. Furthermore, the nanotoxicity and biosafety of these nanosponge-based systems utilized for water treatment should be comprehensively evaluated. Herein, recent advancements in the design and deployment of nanosponge-based systems for removing organic/inorganic pollutants from water and wastewater are deliberated with an emphasis on challenges and perspectives.