Aquatic assessment of the chelating ability of Silica-stabilized magnetite nanocomposite to lead nitrate toxicity with emphasis to their impact on hepatorenal, oxidative stress, genotoxicity, histopathological, and bioaccumulation parameters in Oreochromis niloticus and Clarias gariepinus.

BACKGROUND: In recent years, anthropogenic activities have released heavy metals and polluted the aquatic environment. This study investigated the ability of the silica-stabilized magnetite (Si-M) nanocomposite materials to dispose of lead nitrate (Pb(NO3)2) toxicity in Nile tilapia and African catfish. RESULTS: Preliminary toxicity tests were conducted and determined the median lethal concentration (LC50) of lead nitrate (Pb(NO3)2) to Nile tilapia and African catfish to be 5 mg/l. The sublethal concentration, equivalent to 1/20 of the 96-hour LC50 Pb(NO3)2, was selected for our experiment. Fish of each species were divided into four duplicated groups. The first group served as the control negative group, while the second group (Pb group) was exposed to 0.25 mg/l Pb(NO3)2 (1/20 of the 96-hour LC50). The third group (Si-MNPs) was exposed to silica-stabilized magnetite nanoparticles at a concentration of 1 mg/l, and the fourth group (Pb + Si-MNPs) was exposed simultaneously to Pb(NO3)2 and Si-MNPs at the same concentrations as the second and third groups. Throughout the experimental period, no mortalities or abnormal clinical observations were recorded in any of the treated groups, except for melanosis and abnormal nervous behavior observed in some fish in the Pb group. After three weeks of sublethal exposure, we analyzed hepatorenal indices, oxidative stress parameters, and genotoxicity. Values of alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), urea, and creatinine were significantly higher in the Pb-intoxicated groups compared to the control and Pb + Si-MNPs groups in both fish species. Oxidative stress parameters showed a significant decrease in reduced glutathione (GSH) concentration, along with a significant increase in malondialdehyde (MDA) and protein carbonyl content (PCC) concentrations, as well as DNA fragmentation percentage in the Pb group. However, these values were nearly restored to control levels in the Pb + Si-MNPs groups. High lead accumulation was observed in the liver and gills of the Pb group, with the least accumulation in the muscles of tilapia and catfish in the Pb + Si-MNPs group. Histopathological analysis of tissue samples from Pb-exposed groups of tilapia and catfish revealed brain vacuolation, gill fusion, hyperplasia, and marked hepatocellular and renal necrosis, contrasting with Pb + Si-MNP group, which appeared to have an apparently normal tissue structure. CONCLUSIONS: Our results demonstrate that Si-MNPs are safe and effective aqueous additives in reducing the toxic effects of Pb (NO3)2 on fish tissue through the lead-chelating ability of Si-MNPs in water before being absorbed by fish.

Effect of titanium oxide/reduced graphene (TiO2/rGO) addition onto water flux and reverse salt diffusion thin-film nanocomposite forward osmosis membranes.

Thin-film nanocomposite (TFN) forward osmosis (FO) membranes have attracted significant attention due to their potential for solving global water scarcity problems. In this study, we investigate the impact of titanium oxide (TiO2) and titanium oxide/reduced graphene (TiO2/rGO) additions on the performance of TFN-FO membranes, specifically focusing on water flux and reverse salt diffusion. Membranes with varying concentrations of TiO2 and TiO2/rGO were fabricated as interfacial polymerizing M-phenylenediamine (MPD) and benzenetricarbonyl tricholoride (TMC) monomers with TiO2 and its reduced graphene composites (TiO2/rGO). The TMC solution was supplemented with TiO2 and its reduced graphene composites (TiO2/rGO) to enhance FO performance and reverse solute flux. All MPD/TMC polyamide membranes are characterized using various techniques such as scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle measurements. The results demonstrate that incorporating TiO2/rGO into the membrane thin layer improves water flux and reduces reverse salt diffusion. In contrast to the TFC membrane (10.24 L m-2h-1 and 6.53 g/m2 h), higher water flux and higher reverse solute flux were detected in the case of TiO2and TiO2/rGO-merged TFC skin membranes (18.81 and 24.52 L m-2h-1 and 2.74 and 2.15 g/m2 h, respectively). The effects of TiO2 and TiO2/rGO stacking on the skin membrane and the performance of TiO2 and TiO2/rGO skin membranes have been thoroughly studied. Additionally, being investigated is the impact of draw solution concentration.

Fabrication of cerium titanate cellulose fiber nanocomposite materials for the removal of methyl orange and methylene blue from polluted water by photocatalytic degradation.

In this study, cellulose fibers (Cf), extracted from sunflower seed husk, and different molar ratios of cerium titanate (Ce-Ti) NPs were prepared from sunflower seed husk extract by a green biosynthesis approach. Cf and Ce-Ti NPs were reacted via cross-linking reaction to synthesize a novel nanocomposite photocatalyst of Ce-Ti/Cf. Using Fourier-transform infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM-EDX) spectroscopy, all manufactured materials were characterized. The results obtained from FTIR and EDX analyses indicated that Cf and its nanocomposites (0.1 Ce-Ti/Cf, 0.3 Ce-Ti/Cf, and 0.5 Ce-Ti/Cf) were successfully prepared by harnessing biomass extract from sunflower seed husk. Furthermore, XRD revealed that the degree of crystallinity of the nanocomposites was enhanced by increasing the molar ratios of the Ce-Ti NPs. The photocatalytic activity of as-fabricated 0.1 Ce-Ti/Cf, 0.3 Ce-Ti/Cf, and 0.5 Ce-Ti/Cf nanocomposite samples was investigated on methylene blue (MB) and methyl orange (MO) dyes as model organic compounds found in wastewaters. The effects of dose, contact time, and pH on the photocatalytic activity of the synthesized nanocomposites, the photodegradation kinetic parameters of MB, and MO degradation with/without the addition of H2O2 were also studied. The results revealed that high photodegradation efficiency could be obtained as the ratio of TiO2 in the Ce-Ti nanocomposite formula increases. Moreover, after sunlight irradiation, the adsorption capacity and the dye decomposition ratio significantly increase during the early contact time and reach equilibrium at about 240 and 120 min for 0.5 Ce-Ti/Cf nanocomposite photocatalyst in the absence and presence of hydrogen peroxide, respectively. In light of the obtained results and the practical wastewater treatment study conducted, the prepared photocatalyst from Ce-Ti/Cf nanocomposites could be a promising material for treating dye wastewater especially collected from Egypt.

Green synthesis of ZnO, MgO and SiO2 nanoparticles and its effect on irrigation water, soil properties, and Origanum majorana productivity.

The synthesis of different metal oxide nanoparticles (NPs) (e.g., ZnO, MgO and SiO2) using green methods is a promising alternative to traditional chemical methods. In this work, ZnO, MgO, and SiO2 NPs were prepared using lemon peel extract. The synthesized NPs were characterized using Fourier transform infrared spectroscopy, UV-Visible spectroscopy, X-ray diffraction, and transmission electron microscopy. Also, the effects of the green synthesis of different NPs on the irrigation water quality, the availability of some heavy metals in soil and plants, and the productivity of Origanum majorana (marjoram) were studied in detail. The obtained results showed that the addition of the NPs resulted in noticeable variations in the removal percentages of Cu2+ and Fe3+ from aqueous solutions. The maximum values obtained for the adsorption of Cu(II) on ZnO, MgO, and SiO2 NPs within the pH values of 3-5 were 89.9%, 83.3%, and 68.36%, respectively. Meanwhile, the maximum adsorption values of Fe(III) at pH 3.3 were 82%, 80%, and 65% for ZnO, MgO, and SiO2 NPs, respectively. Clearly, the application of the NPs effectively reduced the available Cu2+ in the studied soil samples in the following order: Zn2 > Zn1 > Mg2 > Si2 > Mg1 > Si1 > C (control). The highest values of available Cu2+ were observed in the control treatment, whereas the lowest values were obtained when Zn2 was added. The same tendencies were observed with substantial concentrations of Fe. The addition of NPs to the soil samples positively affected the plants' Cu2+ uptake. The effects of NPs and the additions of Cu2+ and Fe3+ on the availability of nitrogen, phosphorus, and potassium (NPK) in the soil system were very completed and osculated from one treatment to another. The same tendencies were observed with the total concentration of NPK in plants.

Utilization of rice husk and waste aluminum cans for the synthesis of some nanosized zeolite, zeolite/zeolite, and geopolymer/zeolite products for the efficient removal of Co(II), Cu(II), and Zn(II) ions from aqueous media.

In this paper, rice husk and waste aluminum cans were exploited as silicon and aluminum sources, respectively for the low-cost synthesis of some nanosized zeolite, zeolite/zeolite, and geopolymer/zeolite products. XRD confirmed that the synthesized geopolymer/zeolite products are geopolymer/zeolite A (has a crystallite size of 58.44 nm & abbreviated as G1) and geopolymer/faujasite (has a crystallite size of 25.58 and 20.26 nm & abbreviated as G2 and G3, respectively). Also, the synthesized zeolite products are sodium aluminum silicate hydrate (has a crystallite size of 27.65 and 41.85 nm & abbreviated as H1 and H2, respectively). Besides, the synthesized zeolite/zeolite product is sodium aluminum silicate hydrate/zeolite A (has a crystallite size of 66.01 nm and abbreviated as H3). Moreover, the synthesized products were characterized using other tools such as HR-TEM, FE-SEM, EDX, and FT-IR. The synthesized products were efficiently applied for removing Co(II), Cu(II), and Zn(II) ions from aqueous media and wastewater which was taken from Abuzaabal- Qalyubiyah-Egypt. The maximum uptake capacity of G3 sample toward Co(II), Cu(II), and Zn(II) ions is 134.24 ± 1.26, 126.26 ± 0.32, and 131.93 ± 0.87 mg/g, respectively. The uptake of the studied metal ions is spontaneous, chemical, exothermic, and fitted well with the Langmuir isotherm and pseudo-2nd-order kinetic model.

High-flux TFN nanofiltration membranes incorporated with Camphor-Al2O3 nanoparticles for brackish water desalination.

A new approach of highly fluxes thin film nanocomposite (TFN) nanofiltration (NF) membranes is reported. The fabricated module was made by incorporation of commercial-Al2O3 (CO.TFN) and camphor-Al2O3NPs (CA.TFN) into polyamide layers throughout the interfacial polymerization method. A simple biological reduction technique was adopted in preparation of camphor-Al2O3 NPs by using CinnamomumCamphora (CC) leaf extract. The crystallography of the commercial and camphor-Al2O3 NPs was examined by XRD and FTIR analyses. The CO.TFN and CA.TFN membranes were characterized by determining their surface roughness, pore size, porosity, zeta potential and contact angle parameters. The morphology and the cross-sectional of the NF membranes were studied by atomic force microscope (AFM) and scanning electron microscope (SEM). NF performance was investigated at various Al2O3 NPs loads, applied pressure, and time. The results, of the membranes fabricated at low cost, showed the high permeable flux and elimination of multivalent cations (Mg2+, Ca2+, and water softening). Incorporating 0.98 mM of camphor-Al2O3 NPs into the TFC membrane increased the water flux up to 4 times compared to only 1.5 times for commercial-Al2O3 NPs. Moreover, the salt rejection of CO.TFN and CA.TFN NF membranes increased to 95.1% and 96.5%, respectively for the feed solution (2 g/L Na2SO4 at 25 °C). The optimized NF membrane module of 0.98 mM camphor-Al2O3-NPs (CA.TFN) shows the maximum water flux 69.0,62.2, 60.5 and 55.4 L/m2.h for the feed solutions of following salts NaCl, Na2SO4, MgCl2 and MgSO4 with high salt rejections 92.4%, 96.5%, 91.7% and 95.3%, respectively. This proves that camphor-Al2O3 NPs have a significant role in increasing the membrane hydrophilicity. Hence, the CA.TFN membrane module proved to be a promising candidate for the real brackish water desalination as that collected from Marsa Alam, Egypt.

Facile synthesis of Fe2O3 nanoparticles from Egyptian insecticide cans for efficient photocatalytic degradation of methylene blue and crystal violet dyes.

In this study, Fe2O3 (hematite) nanoparticles with different crystallite sizes (40-59 nm) were synthesized from Egyptian insecticide cans using the combustion method. The organic fuels were urea, glycine, L-alanine, and L-valine. Fe2O3 nanoparticles were characterized utilizing different devices such as BET, PL, FT-IR, XRD, HR-TEM, FE-SEM, UV-Vis, and DTG. Crystal violet (CV) and methylene blue (MB) dyes were efficiently removed from aqueous solution by photocatalytic degradation under UV irradiation in the presence of Fe2O3 and H2O2. The % degradation of 50 mL crystal violet or methylene blue dye (20 mg/L) using 0.1 g Fe2O3 in the presence of H2O2 was 100% after 30 or 40 min, respectively. Also, the degradation processes are fitted well with the first order model. Besides, the photocatalytic activity of Fe2O3 unaltered even after it was reused three times. Hence, the synthesized Fe2O3 nanoparticles can be considered a promising and efficient photocatalyst for the degradation of crystal violet and methylene blue dyes.