Journal of Material and Process Technologies

Phytochemical Screening and Antibacterial Activity of Stem Bark Extract of Maesa Lanceolate and Isolated Compounds

salah hamza sherif — 2024-12-30

Maesa lanceolate locally kmown as “Kowwaada” in Hadiya, and “Yekalaha zaf” in Amharic is one of the species in Primulaceae family whoseaerial and axial parts have been in wide use for the treatment of a variety of diseases in different parts of the world. Its stem bark in association with leaves or alone is employed for medicinal value among the Hadiya community of Southern Ethiopia. The stem bark of Maesa lanceolata was collected, chopped into pieces, air-dried, ground and extracted successively with dichloromethane (DCM) and methanol (MeOH) to afford 0.8% DCM and 12.26% methanol crude extracts, respectively. The methanol crude extract which showed clear TLC profile and yield, was subjected to silica gel column chromatography in n-hexane to ethyl acetate solvent system with increasing polarity and two compounds namely, 2, 5-dihydroxy-3-methyl-6-(nonadec-14-enyl)-1, 4-benzoquinone and isopropyl oleate were isolated. The methanol extract as well as the isolated compounds were investigated for their in vitro antibacterial activities against two gram-negative bacterial strains (P. aeruginosa (ATCC27853), E. coli (ATCC25922), and two gram-positive bacterial strains (S. pyogen (ATCC19615), S. aureus (ATCC25923) using ampicillin as a positive control. The results showed that the methanol crude extract and isolated compounds were all active against tested bacterial strain but 2,5-dihydroxy-3-methyl-6-(nonadec-14-enyl)-1, 4-benzoquinone was the most active among them. The later exhibited 8mm, 8.5mm, 8 mm, and 9 mm zones of inhibitions at concentrations of 350 µg/ml and 9.5mm, 10mm, 9mm, and 11mm at (400 µg/ml) against E. coli, S. aureus, P. aeruginosa and S. pyogen, respectively. The results further indicated the increase in the inhibition zone with concentration. This study supports the traditional medicinal uses of Maesa lanceolata for the treatment of infectious diseases.

Application of Portable X-Ray Fluorescence (PXRF) for compositional analysis of metallic heritages of Ethiopia and implications

Girma Woldetinsae — 2024-12-30

In this study data generated with Portable X-Ray Fluorescence (PXRF) through community service in one of the Ethiopian Orthodox Church (EOTC) museum is used. The PXRF was applied to determine the type, mineral content and quality of gold (karat) of heritages along with visual observations. Measurements of elemental compositions on more than 331 contemporary and antique museum items helped to know the proportions of major and minor trace elements. The hand and processional crosses in the museum indicated two or three elemental compositions of major elements (Gold (Au), Silver (Ag) and Copper (Cu); Gold and Copper; Silver and Copper; Silver and Nickel (Ni)). Minor elements include Chromium (Cr), Tungsten (W) and Titanium (Ti) and particularly observed on memorials and souvenirs (e.g., medals, pendants and watches). Minor amounts of Tungsten which can tolerate high temperatures are added as part of a jewelry practice to increase durability and toughness. The presence of Chromium indicated to avoid tarnishes on Silver made items. Some heritages are decorated with unidentified colored stones. Similar ones are seen in other Ethiopian museums. Documentation of the colored stones and associated metals in terms of (e.g. carat, color, cut, benefits) are not available. These gaps along with destructive goldsmith practices for identification of gold karats and the lack of modern visiting applications would expose the heritages for covert theft. The FDRE Mines proclamation to regulate transactions of minerals does not include specific articles about treatments and required declarations. The absence of national labs for identification, certification and proofing standards further exacerbates the challenge by making the regulatory process inept. The application PXRF is very crucial for quick feedbacks about the compositions of the heritages without damaging the physical appearance and protection of heritages in all Ethiopian museums.

Magnetically recyclable Activated Carbon Prepared from Brewer’s Spent Grain and Its Chromium (VI) Adsorption study

Getachew Adam Adam — 2024-12-30

Magnetic Activated carbon was prepared from a brewery spent grain (BSG) and magnetite using the sol-gel method. The crystal structure, molecular constituent, morphology, and specific surface area of the prepared magnetic activated carbon (MAC) were analyzed using XRD, FTIR, SEM, and BET techniques. The characterization results revealed the successful preparation of MAC material. Thereafter, the removal efficiency of MAC for Cr (VI) from synthetic wastewater and real wastewater was investigated. Parameters of adsorption processes were optimized numerically and found that solution pH of 2, initial concentration of 40 mg L^-1, an adsorbent dosage of 5 g L^-1, and a contact time of 30 min were the optimal conditions for removal of Cr (VI) with 97.5% efficacy. The adsorption studies were consistent with the pseudo-second-order kinetics and with Temkin isotherm models with a high regression coefficient (R²) of 0.995 and 0.996 respectively. Moreover, at the optimum conditions, the MAC adsorbent showed the removal of 318 ± 14 mg/L chemical oxygen demand (COD), and 41.3±7.8 mgL^-1 biochemical oxygen demand (BOD) of real wastewater collected from the local tannery industry in Ethiopia. Furthermore, the recycled MAC was used repeatedly and showed comparable removal efficiency for five consecutive cycles. As such, magnetic activated carbon made from BSG seems an alterantive adsorbent in wastewater treatment.

Keywords: Brewery spent grain, Magnetic Activated Carbon, Adsorption, Chromium (VI)

Synthesis And Characterization of Modified Silica Gel Supported Silver Nanoparticles using Batch Studies for Disinfection of Escherichia Coli and Staphylococcus Aureus for Drinking Water

Belete Tessema — 2024-12-30

AgNPs were synthesised using Vernonia amygdalina leaf extract as a reducing agent in an AgNO₃ solution. The synthesized AgNPs solution was characterized and used for the synthesis of modified silica gel (MSG)-supported AgNPs (MSG-AgNPs). After being treated with HCl, the grounded Filagot teff straw was calcined for 2 h at 500, 600, 700, 800, and 900 °C. The sol-gel method was used to create the silica gel, and NaOH solution was used to treat it. An 80.4% SG yield with a 99.39% purity and the largest surface area (807.163 m²/g) were obtained at 700 °C and were chosen for additional analysis. Trimethylchlorosilane (TMCS)/ethanol/hexane was then added to SG at volume/vol ratios of 15/25/100, 25/25/100, 35/25/100, and 50/25/100. A modified SG mixture of TMCS/ethanol/hexane with a maximum surface area of 510.4 m²/g was produced at 25/25/100 (vol/vol) of the mixture. Using the sol-gel process, the AgNPs that were produced with Vernonia amygdalina leaf extract were impregnated on the MSG. Prior to impregnating AgNPs onto the MSG, several quantities of AgNPs (1.5, 3, 6, and 9 mM) were made. The solutions were then supplemented by MSG. For 1.5, 3, 6, and 9 mM solutions, the MSG-AgNPs composites had surface areas of 475.0, 457.3, 438.5, and 410.9 m²/g, respectively. Finally, batch disinfection experiments against S. aureus and E. coli were conducted. In the batch research, MSG-AgNPs impregnated with 9 mM AgNPs reduced the concentration of E. coli from 10⁴ and 10⁵ to 0.0 CFU/mL in 10 min and from 10⁶, 10⁷, and 10⁸ to 0.0 CFU/mL in 60 min.