Effect of magnetic field on nano-magnetite composite exhibits in ion-adsorption

Efficient degradation of orange II by core shell CoFe2O4-CeO2 nanocomposite with the synergistic effect from sodium persulfate

Novel core shell CoFe₂O₄-CeO₂ (CoFe-Ce) nanocomposite was synthesized and investigated as an efficient photocatalyst to activate sodium persulfate (Na2S2O8, PS) for orange Ⅱ (OⅡ) degradation. The CoFe-Ce nanocomposite was successfully designed and synthesized by a facile hydrothermal reaction followed by calcination and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), and vibrating sample magnetometer (VSM). Compared with pure CoFe₂O₄ and CeO₂, the photocatalytic efficiency of CoFe-Ce nanocomposite was significantly improved. Under the irradiation of visible light, the catalytic degradation efficiency of orange II could reach to 98.5% within 60 min. Additionally, the as-prepared material could be recycled for at least five times using magnetic separation ability of the nanocomposite, and during the cycling the dye degradation rate was almost unchanged. The active species produced during the degradation were studied by classical quenching experiments, and the different types of free radicals produced in the system were further confirmed by electron paramagnetic resonance (EPR) spectroscopy. This novel nanocomposite is expected to have potential application for degradation of organic pollutants in wastewater by utilizing solar energy.

Critical review on hazardous pollutants in water environment: Occurrence, monitoring, fate, removal technologies and risk assessment

Water is required for the existence of all living things. Water pollution has grown significantly, over the decades and now it has developed as a serious worldwide problem. The presence and persistence of Hazardous pollutants such as dyes, pharmaceuticals and personal care products, heavy metals, fertilizer and pesticides and their transformed products are the matter of serious environmental and health concerns. A variety of approaches have been tried to clean up water and maintain water quality. The type of pollutants present in the water determines the bulk of technological solutions. The main objective of this article was to review the occurrences and fate of hazardous contaminants (dyes, pharmaceuticals and personal care products, heavy metals, and pesticides) found in wastewater effluents. These effluents mingle with other streams of water and that are utilized for a variety of reasons such as irrigation and other domestic activities that is further complicating the issue. It also discussed traditional treatment approaches as well as current advances in hazardous pollutants removal employing graphite oxides, carbon nanotubes, metal organic structures, magnetic nano composites, and other innovative forms of useable materials. It also discussed the identification and quantification of harmful pollutants using various approaches, as well as current advancements. Finally, a risk assessment of hazardous pollutants in water is provided in terms of the human health and the environment. This data is anticipated to serve as a foundation for future improvements in hazardous pollutant risk assessment. Furthermore, future studies on hazardous pollutants must not only emphasize on the parent chemicals, as well as on their possible breakdown products in various media.