Characterization and use of activated carbon synthesized from sunflower seed shell in the removal of Pb(II), Cd(II), and Cr(III) ions from aqueous solution.

In this work, carbon-based nanomaterials such as active carbon which is prepared from common sunflower (Helianthus annuus) seed shell, and the characterization of the activated carbon NPs were studied using FTIR (Fourier transform infrared spectroscopy), XRD, SEM, EDS, and DTA techniques. Activated carbon NPs have been used in the adsorption of Pb(II), Cd(II), and Cr(III) ions from the aqueous phase. The results showed the highest adsorption efficiency was 99.9%, 92.45%, and 98% for Pb(II), Cd(II), and Cr(III) ions respectively at a temperature of 25 °C, pH = 7-9, and a time of 60 and 180 min, in addition to the accordance of the adsorption models for activated carbon with the Freundlich isotherm model at the value of R2 (0.9976, 0.9756, and 0.9907) and Langmuir isotherm model (0.966, 0.999, and 0.9873) of the Pb(II), Cd(II), and Cr(III) ions, respectively. We conclude the possibility of using activated carbon to have an extremely high sorption capacity across the conditions tested, with the highest adsorption efficiency having been >99% for Pb(II), Cd(II), and Cr(III) ions within the pH range 7-9 and a contact time of 60 to 180 min.

Investigation the effect of nanocarbon tube prepared from tea waste on microstructure and properties of cement mortar.

Environmental contamination and the massive high cost of waste disposal have been a huge concern for scholars throughout the globe, prompting them to alternatives of recycling waste materials in various implementation fields. The rising expenditure on disposal and the shortage of naturally main resources such as aggregate have increased interest in reusing recycled waste materials to manufacture concrete and mortar. The annual consumption of a country's population of hundreds of tons of black tea results in considerable numbers of discarded teabags. These huge quantities are disposed in landfills without being recycled or otherwise used. Moreover, such landfills are considered one of the country's biggest global issues. Therefore, the aim of this experimental work is to investigate the influence of nanocarbon tube produced from tea waste as cement replacement materials in mortar mixtures. Cement mortar mixes contain four replacement levels (1%, 2%, 3%, and 4%) of cement with nanocarbon tube produced from tea waste. The compressive strength, ultrasonic pulse velocity, and water absorption were tested to demonstrate the effect of the nanocarbon tube made from recycled tea waste on the mechanical properties of the mortar mix. The fresh properties such as flow rate were evaluated in accordance to specific standards. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDX) analyses were performed to demonstrate the microstructure of the mixtures. The results show that the fresh properties (flowability) of mortar containing nanocarbon tubes from tea waste were improved with the increase of the replacement ratio. In addition, the compressive strength was improved by substitution of up to 2%. For the other levels of substitution, it decreased with an increasing replacement percentage. In contrast, the density had increased with the increase of substitution levels of the tea waste. Based on the results of the experiments, it seems that the suggested biomixture could increase the compressive strength of the material by up to 2% of the replacement at 28 days of curing.

Biosynthesis and antibacterial activity of manganese oxide nanoparticles prepared by green tea extract.

Amongst chemical and physical techniques, the biosynthesis method of metal nanoparticles has received the interest of many researchers owing to its environmental safety, simplicity and inexpensiveness. Manganese oxide nanoparticles (MnO NPs) were successfully synthesised using green tea extract as the reducing agent and characterised by UV-Vis spectroscopy, X-ray diffractometry and Fourier transform infrared spectroscopy. The shape and size of the MnO NPs were obtained by scanning electron microscopy. The size of the MnO NPs was 20-30 nm. The MnO NPs exhibited strong antibacterial activity against pathogenic bacteria, namely, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa, with inhibition zones of 12, 14 and 18 mm, respectively. Moreover, the minimum inhibitory concentration (MIC) of the MnO NPs was 12.5 U/mL as determined by resazurin microtitre assay. The activities of some antibiotics remarkably increased when combined with MnO NPs (at MIC).