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Photoreduction of chromium hexavalent ions (Cr6+) from the aquatic environment is urgently needed due to its impairing effect on human health. Adsorption, photoreduction, and desorption of reduced trivalent chromium (Cr3+) at the photocatalyst surface are all significant factors for determining photocatalytic reduction efficiency. Herein, we report a facile, template-free hydrothermal approach to fabricate green and homogeneous mixed-phase (1 T/2H) molybdenum disulfide (MoS2) nanosheets for highly efficient removal of Cr6+ ions and pharmaceuticals from wastewater. The nanostructure and morphology of the obtained (1 T/2H) MoS2 are investigated; the calculated crystallite size of the (2H/1 T) MoS2 nanosheets is found to be 1.7 nm. The presence of surface functional groups adsorption, and photoreduction processes is confirmed by spectroscopic studies using Fourier transform infrared (FTIR) spectra. Additionally, Raman spectra confirmed the formation of 1 T/2H mixed-phase MoS2 which illustrates its crystal phases, structure, and chemical composition. Moreover, the point-of-zero charge analysis revealed the positively charged surface in the acid system. The obtained results revealed the non-toxicity of MoS2 nanosheets at doses lower than 1000 ppm. The results reveal that the (1 T/2H) MoS2 exhibited impressive reduction performance for Cr6+; the reduction efficiency of chromium Cr6+ is 100% under simulated sunlight, 90 min at pH (3). Further spectroscopic study results confirm the importance of the adsorption step in Cr6+ ions photoreduction. Different pharmaceuticals are also completely degraded over (1 T/2H) MoS2 nanosheets. Interestingly, complete removals of E. coli O157:H7, Listeria monocytogenes, and Candida albicans were observed at a dose of MoS2 nanosheets of 250 ppm after a contact time of 30, 30, and 45 min, respectively. The results of the current work could lead to a rational design of high-performance nanosheets for the efficient decontamination of heavy metals, pharmaceuticals, and pathogens from aquatic environments. [ABSTRACT FROM AUTHOR]

Inorganic polymeric ferric chloride (POFC) coagulant with proposed structure of Fen (Cl2.2OH0.8)n is synthesized using waste materials and characterized by XRD. In the current work scrutinized efficiency of POFC for paper mill wastewater (PMW) treatment using response surface methodology (RSM) with central Composite Design (CCD) modeling. Different factors; dose, rapid mixing speed, and rapid mixing time are used for optimize the coagulation process using POFC for treating PMW. The turbidity and chemical oxygen demand (COD) removals are the indicators for assessing POFC efficiency. The obtained result for XRD confirms the production of new material of inorganic polymeric coagulants. Based on RSM modelling, there is a high correlation between the experimental and predicated removals of turbidity and COD. Subsequently, the model is significantly applied for predicating COD and turbidity removals at different operation condition. Conclusively, the obtained results proposed for practical application of POFC coagulant for treatment of paper mill wastewater for COD and turbidity elimination. Furthermore, the applied RSM with CCD is talented model for optimizing treatment of PMW. [ABSTRACT FROM AUTHOR]

In this work, superparamagnetic Fe3O4/C core/shell nanoparticles (NPs) were synthesized using a room‐temperature and green route combining co‐precipitation method, followed by hydrothermal process. The prepared nanoparticle was utilized as an adsorbent for the removal of Pb+2 ions from a wastewater. The effect of various parameters; such as pH, dose of adsorbent, contact time and concentration of lead ions on the adsorption capacity were examined in details. The adsorption capacity (qm) of Fe3O4/C NPs was estimated from the Langmuir isotherm curve and was found to be 244 mgg−1. Interestingly, the produced Fe3O4/C NPs exhibited a rapid removal of toxic lead metal ions from wastewater effluents and the adsorption kinetics is well described by pseudo‐second‐order model. Furthermore, the data of Pb2+ adsorption is best fit for the Langmuir model. Moreover, the Fe3O4/C core/shell NPs were recycled and reused for at least five times without a significant loss of adsorption efficiency. A cconvenient and cost‐effective hydrothermal approach is developed for the synthesis of highly efficient superparamagnetic Fe3O4/C core/shell NPs as adsorbent materials for the removal of toxic lead metal ions from wastewater [ABSTRACT FROM AUTHOR]

Innovative simple method for the preparation of simonkolleite-TiO2 photocatalyst with different Zn contents was achieved. The prepared photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), FT-IR, Raman and diffuse reflectance spectroscopy techniques. The photocatalytic activities of the materials were evaluated for the simultaneous detoxification of hexavalent chromium (Cr(VI)) and oxidation of organic compounds commonly present in wastewater under simulated solar light. The best photoreduction efficiency of Cr(VI) has been achieved at 1000 ppm simonkolleite-TiO2 photocatalyst of 5% Zn/TiO2 weight ratio, and pH value of 2.5 to enhance the adsorption onto catalyst surface. Photoreduction was significantly improved by using formic acid as holes scavenger owing to its chemical adsorption on the catalyst surface. Finally, 100% photoreduction of Cr(VI) could be achieved using formic/simonkolleite-TiO2 systems under sunlight. [ABSTRACT FROM AUTHOR]