Efficient removal of methyl orange using magnesium oxide nanoparticles loaded onto activated carbon

ABSTRACT. In this work, an activated carbon composite made with magnesium oxide nanoparticles (MgONP-AC) was effectively utilized for methyl orange (MO) adsorption. The effect of pH (6-10), mass of MgONP-AC (0.1-0.3 g/L), initial MO concentration (10-30 mg/L), and temperature (283-323 K) on MO removal was investigated using a central rotatable composite experimental design based on the response surface technique (RSM) at an equilibrium agitation period of 60 min. The studies predicted the optimal MO removal of 98.99% at pH 7.68, MgONP-AC dosage of 0.24 g/L, and starting MO concentration of 15 mg/L, and temperature of 313 K. Furthermore, an artificial neural network (ANN) was utilized to simulate MO adsorption, and it properly predicted MO removal using mean squared error (MSE) and R2 for the testing data. The ANN predicts a maximum removal of 99.63% with ANN with R2 = 0.9926. The kinetic results suited the pseudo-second order kinetic equation, and the data from the equilibrium investigations corresponded well with the Langmuir isotherm (maximum uptake capacity qmax = 346 mg/g). Endothermic, spontaneous, and physical adsorption were discovered during the thermodynamic investigations.   KEY WORDS: Adsorption, Artificial neural network, Experimental design, isotherms, Kinetics, Methyl orange, MgONP-AC   Bull. Chem. Soc. Ethiop. 2022, 36(3), 531-544.                                                                DOI: https://dx.doi.org/10.4314/bcse.v36i3.

Investigation of structural and diffuse phase transition of new nano lead-free system xBAO – yBZT − (1 − x − y) BCT

We present in this article the latest development of single-phase nanocrystalline ceramics, x(BiAlO3) − y(BaZr0.2Ti0.8O3) − (1 − x − y) (Ba0.7Ca0.3TiO3), abbreviated as xBAO − yBZT − (1 − x − y) BCT with (x, y) = (0, 0.50), (0.01, 0.49), (0.03, 0.47) and (0.1, 0.4), which were prepared using a high-energy ball milling technique. In the current study, BZT − xBCT has been selected as a host system to be incorporated into BiAlO3. Their properties of structure, relative dielectric permittivity (ε), diffuse phase transition (γ), peak broadening (δγ) and deviation from Curie–Weiss law (ΔTC) were systematically investigated. However, the decreasing trend of Curie temperature (Tc) in the system does not obey the Vegard’s law. Analysis of X-ray diffraction patterns shows the solid solubility of (Bi3+, Ca2+) into A-site and that of (Zr4+, Al3+) into B-site of pure BaTiO3 lattice of tetragonal symmetry with space group P4mm. The values of γ (1.75 to 1.63) confirmed that the ceramic has intermediate behavior between the relaxor and normal ferroelectric, which is evaluated by modified Curie–Weiss law. The high value of quality factor (115), when x = 0.01, y = 0.49 at 1-kHz frequency and temperature 323 K (50°C), decreases with the increasing frequency

Carbon-Based Nanoadsorbents for the Removal of Emerging Pollutants

Emerging contaminants (ECs) are substances that have been detected in water but have not been thoroughly tested or regulated. Pesticides, cosmetics, pharmaceuticals, and other medications are examples of compounds in this category. Even at low quantities, these pollutants can harm human health and the environment; therefore, avoiding them is critical. The consequences of EC pollution on the endocrine, hormonal, and genetic systems are causing significant concern. Even with current best practices and available technology, it is difficult to totally eliminate ECs from municipal and industrial wastewater treatment plants. Adsorption has been the method of choice for EC removal since it is less costly, more effective, and easier to use. To treat ECs, newer generation nanoadsorbents are employed. Adsorption was greatly enhanced by functional changes to the adsorbent surface. Carbon nanostructures are widely used as adsorbents because of their outstanding surface properties, adaptability, large surface area, adjustable structural changes, and high chemical stability. This review reviews and examines recent research on the production and use of carbon-based nanoadsorbents. The emphasis is on carbon nanotubes, graphene, and graphene-derived adsorbents. It is being investigated if these adsorbents can be used to extract hormone-disrupting chemicals and other emerging pollutants. The sources and classification of these pollutants, treatment knowledge gaps, and novel prospects for increasing carbonaceous nanoadsorbent utilization were all explored. The environmental and health problems associated with EC use are also studied