Departments of Chemistry

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PHYTOCHEMICAL INVESTIGATION AND ANTIBACTERIAL ACTIVITY EVALUATION OF THE ROOT EXTRACTS OF OTOSTEGIA INTEGRIFOLIA
(HAWASSA UNIVERSITY, 2023-05) FELEKE TIGABIENEH MOGES
Medicinal plants have been the oldest and most widely used system of medicine to treat diseases caused by different pathogens and fight infections worldwide since ancient times. Recently, including in Europe and America, there has been a growing interest in medicinal plants. Traditionally, O. integrifolia leaves have been used in Ethiopia & Eritrea as insecticides, to treat tonsillitis, uvulitis, hypertension, etc. Its roots have also been used as an anthelmintic and for the treatment of lung conditions. Thus, this study was aimed at phytochemical investigation and antibacterial activity evaluation of the root extracts of Otostegia integrifolia. The roots were collected, washed, chopped into pieces, air-dried, ground and extracted successively with CHCl3, CHCl3/CH3OH (1:1 v/v), and CH3OH to obtain 0.4, 3.77, and 1.27 % of crude extracts, respectively. The phytochemical screening test revealed the absence of alkaloids and anthraquinones and the presence of terpenoids, phenols, flavonoids, saponins, tannins, steroids, coumarins, carbohydrates, and glycosides in all extracts except phenols, which is absent in CHCl3 extracts. The CHCl3/CH3OH (1:1 v/v) extract was subjected to gradient elution of silica gel column chromatography in n-hexane/EtOAc solvent system. The elution was result in a total of 122 fractions, and fractions 48-51 (FT1) and 59-65 (FT2) had single spots on TLC. Based on the spectral data obtained from IR, 1H NMR, 13C NMR, and DEPT-135, the compounds were proposed to be hystroxene-I for FT1 and Angustanoic acid E for FT2. The extracts and isolated compounds were evaluated for their antibacterial activities against two gram positive bacterial strains (S. pyogen (ATCC19615), S. aureus (ATCC25923)) and two gram negative bacterial strains (P. aeruginosa (ATCC27853), E. coli (ATCC25922)) using ampicillin as a positive control, and all showed positive effects. Among FT1 and all the extracts FT2 exhibited the most effective antibacterial activity and the CHCl3 extract showed the least. The 400 μg/ml of isolate FT2 showed comparible effects (11.5, 12, 11, and 10.5 mm) with Ampicillin (13, 14, 12.5, and 12 mm) on S. aureus, S. pyogen, E. coli, and P. aeruginosa respectively
DETERMINATION OF SELECTED METALS AND NUTRITIONAL COMPOSITION IN PAPAYA (CARCIA PAPYA) AT SAJA DISTRICT, YEM SPECIAL WOREDA, SOUTHERN ETHOIOPIA
(HAWASSA UNIVERSITY, 2023-07) ZEKARIAS ZERFU
Papaya is commonly known for its food and nutritional values throughout the world. The study was aimed to determine the level of selected metals as well as nutritional value of Papaya samples collected from six kebeles of Yem Special Woreda, SNNPRS. The optimized wet digestion method was used in the analysis. The results revealed that papaya has the ability to accumulate relatively higher amounts of Ca and Mg among the determined essential metals. The result of metal analysis revealed that papaya contains appreciable level of essential metals and the level of toxic heavy metals (Pb and Cd ) were below maximum permissible value set by WHO/FAO indicating that the given fruit was safe to use The concentration ranges in dry weight basis in decreasing order were: Ca (7.13 -24.51) >Mg (9.76-10.87) > K (3.83 – 4.64) > Fe (1.18 – 5.76) >Mn (0.19-0.49) > Zn (0.14-0.45)>Pb(0.16-0.24) > Cu (0.14-0.16) >Cd (0.01) mg/kg. The proximate compostion results indicated that the percentage of nutritional value in papaya ranges from (5.90 to 6.37), (70.56 to 72.42), (6.47 to 13.90), (2.08 to 2.85), (1.40 to 2.20), (6.21 to 11.45), (85.44 to 105.28); for ash, moisture, crude protein, crude fat, crude fiber, carbohydrates and total energy respectively. The efficiency of digestion methods was revealed that the excellent recoveries obtained which were found within the acceptable range for the analyzed metals. Regarding the proximate analysis, papaya was a good source of carbohydrate, fat, protein, and fiber and energy contents.
ADSORPTIVE REMOVAL OF LEAD ION FROM AQUEOUS SOLUTION USING CRYSTALINE NANOCELLULOSE PREPARED FROM MAIZE COBS
(2024-03) GETAHUN ESHETU
Heavy metals significantly impact the environment due to their non-biodegradable, toxic, and carcinogenic behaviors. Lead contaminants impose severe health impacts on humans and the water environment. Therefore, eco-friendly and efficient lead ion removal practices such as nanotechnology are an urgent requirement for the abatement of lead pollution. The aim of this study was to evaluate the removal of lead from an aqueous solution using maize cob cellulose Nano crystals. In the present study, crystal Nano cellulose was synthesized from maize cob. The crystal Nano cellulose synthesized was characterized by using FTIR, XRD and SEM. FTIR analysis reveals presence of functional groups with a high chelating capacity, as identified via FTIR. From SEM analysis the crystal Nano cellulose was noticed to be disordered and irregular in shape. The adsorption capacity of the crystal Nano cellos was 3.85 mg/g. The adsorption process was evaluated by adjusting the pH, dose, initial concentration and temperature. Optimum conditions were dose of 0.16 gram initial concentration of 10 ppm, contact time of 115 minute, pH of 6 and temperature of 450 c. Based on the optimal parameters, the kinetics were evaluated using the pseudo first and pseudo second order models based on that pseudo second order more fit than pseudo first order model. Equilibrium data were represented better by the Freundlich model than the Langmuir model which describes multilayer adsorptions. The adsorbent-formulated from crystalline Nano cellulose presented a good capacity to remove lead from aqueous media.
Phytochemical and Antibacterial activity study of the root extract of Ehretia cymosa
(Hawassa University, 2024-05) SITOTA ASAMINEW
Ehretia cymosa is a medicinal plant that is used for traditional medicine in many African countries including Ethiopia. The different plant parts of E. cymosa are used in traditional medicine for the treatment of several health problems such as Toothache, tetanus, dysentery, gastric ulcers, wound healing, and skin diseases. The aim of this study was to investigate chemical constituents, partially characterize isolated compounds of root extract of E. cymosa and testing antibacterial activities of crude extracts and isolated compounds. The successive extraction of the roots 500g powder was carried out using solvent systems n-hexane, dichloromethane, dichloromethane: methanol (50:50 % by volume), and methanol that afforded 2.5 g (0.5%), 3.5 g (0.7%), 15.5 g 3.1%) and 5 g (1%) of crude extracts respectively. Phytochemical screening that was carried out by employing standard procedures revealed the presence of secondary metabolites such as alkaloids, tannins, saponins, steroids, flavonoids, phenols, glycosides, and terpenoids. Thus, dichloromethane: methanol (50:50 % by volume) extract was subsequently subjected to chromatographic separation which led to the isolation of three compounds EC-1, EC-2, and EC-3. Crude extract of dichloromethane/methanol (1:1) was subjected to column chromatography and afforded three compounds partially characterized using spectroscopic UV-Vis and IR analysis. The in vitro antibacterial activity evaluation of the crude extracts and isolated compounds was done on four different bacterial strains S. auras, E. coli, P. aeruginosa, and S. pyogen using the gar diffusion method. Among the bacteria strains used in the study, S. pyogene showed the widest zone of inhibition for methanol extract even though other extracts were antibacterial active enough. The observed antibacterial activities of the crude extracts and isolated compounds justified the traditional use of plants for the treatment of different bacterial infections. Thus, further testing is recommended on a large number of bacterial strains to decide their potential as candidates in the development of antibacterial agents.
MICROBIAL FUEL CELL WITH GREEN SYNTHESIZED CuO BASED POLYANILINE COMPOSITE AS EFFICIENT BIOANODE MODIFIER CATALYST
(HAWASSA UNIVERSITY, 2024-05) BETELEHEM GUTA
Microbial fuel cell is a new technology device that converts chemical energy stored in organic waste into electrical energy by using microorganisms as a catalyst with simultaneous waste water treatment. In this study, low-cost phyto-synthesized CuO nanoparticles integrate with conducting polyaniline (PANI) matrix to form CuO/PANI hybrid nanocomposite was synthesized by in situ polymerization methods and PANI was synthesized by oxidative polymerization method. The synthesized sample were characterized through UV-Vis spectroscopy, FTIR, SEM, and XRD, instruments to examine their optical properties, intermolecular bonding and the existence of functional groups, morphology and crystalline structural respectively. Four single chambered microbial fuel cells (MFCs) was constructed with bare pencil graphite anode, pencil graphite anode modified with CuO, PANI, CuO/PANI nanocomposites and PGEs cathode for all four devices. The average crystalline size for CuO NPs, PANI and CuO/PANI NCs was 28.05 nm, 3.2 nm and 20.6 nm respectively. It was found that the maximum open circuit voltage (OCV) obtained by bare PGE, CuO/ PGE,PANI/PGE and CuO/PANI/PGE was 229 ± 11.3 mV, 315 ± 35.3 mV, 485± 15.5 mV, and 630 ± 10.6 mV respectively. The maximum power density and corresponding current density obtained by CuO/PGE, and PANI/PGE have a value 265.75 mWm−2 & 2134.34 mA m−2 and 387.91 mWm−2 & 2418.06 mAm−2 respectively. A maximum of 416.01 mWm-2 , and 2429.56 mAm-2 power density at corresponding current densities was produced by CuO/PANI/PGE respectively. This was 6.3and 4-fold higher in power and current densities than unmodified PGE have values of 65.67 mWm-2 and 580.21 mAm-2 . From above results modifying anode of MFC with CuO nanoparticles based PANI composite gives a better output as compared with bare PGE in the MFC energy conversion system
PHOTOCATALYTIC DEGRADATION OF CRYSTAL VIOLET UNDER SOLAR IRRADIATION USING A BIOSYNTHESIZED ZnOBASED POLYANILINE
(HAWASSA UNIVERSITY, 2024-05) BELAYNESH SIRIYE TALILA
A morphologically modified PANI/ZnO Nanocomposite was synthesized using leaf extract from Solanecio gigas (S. gigas) a reducing and capping agent for the photocatalytic degradation of Crystal Violet (CV) under natural sunlight irradiation. Additionally, PANI and pure ZnO NPs were synthesized via a green route, and the nanomaterials were characterized using spectroscopic techniques such as UV-Vis, FT-IR, SEM, and XRD. The blue-shift in the absorption peak of PANI/ZnO NCs suggests a change in electronic structure, potentially due to a type-II heterojunction between PANI and ZnO. FTIR analysis revealed red-shifted peaks, indicating hydrogen bonding between ZnO and PANI. Morphologically, the composite material combines the roughness of ZnO NPs with the smoothness of PANI. XRD patterns showed overlapping peaks from the composite with a crystalline size of 5.577 nm, which is smaller than the crystalline size of ZnO NPs (9.455 nm). This reduction in size is likely due to the formation of a polymer-Zn complex on the nanoparticle surface. The photocatalytic activity of the polyaniline/ZnO nanocomposite in degrading CV in aqueous solution under natural sunlight irradiation was evaluated and compared with that of ZnO nanoparticles. The effects of experimental conditions such as pH, photocatalyst dosage, and CV concentration were investigated with 91.20% and 99.06% at pH 11, 99.47% and 99.97% at 0.12 g, and 94.93% and 96.20% at 20 ppm for both ZnO NPs and PANI/ZnO NCs. The ZnO/polyaniline nanocomposite exhibited higher photocatalytic activity at 98.25% compared to ZnO nanoparticles at 92.76% under optimal conditions after 60 minutes of sunlight exposure. Kinetics studies indicated that the degradation rate fit well with the pseudo-first-order kinetics model, showing an R2 value of 0.968 for PANI/ZnO NCs. The composite demonstrated good catalytic activity with four cycles of reusability time compared to non-coated ZnO NPs. These findings highlight the potential of S. gigas plant-assisted PANI/ZnO NCs as effective and sustainable nanocatalysts with promising applications in catalytic decomposition of organic contaminants for environmental remediation
DESIGN AND SYNTHESIS OF SOME NOVEL HYBRID MOLECULES CONTAINING INDOLE AND OXADIAZOLE RING FOR EVALUATION OF ANTIBACTERIAL AND ANTIOXIDANT ACTIVITIES
(HAWASSA UNIVERSITY, 2024-05) AMANUEL ABRIHAM BUDE
Indole-containing oxadiazole compounds have emerged as a versatile class of nitrogencontaining heterocyclic compounds with a wide range of biological activities. These compounds and their derivatives exhibit a diverse array of properties such as antiviral, anticancer, anti-HIV, antioxidant, antimicrobial, antidiabetic, and antimalarial activities. The aim of the study was to design and synthesize some novel hybrid molecules containing an indole and oxadiazole rings, followed by partial characterization of the synthesized compounds using UV-vis and FT-IR spectroscopic techniques, and assessment of their antibacterial and antioxidant activities. The synthetic methodology was initiated by esterification of 2-(1H-indol-3-yl) acetic acid (105aʹ) and 4-(1H-indol-3-yl) butanoic acid (105bʹ) using a catalytic amount of sulfuric acid and excess methanol. This process resulted in the formation of methyl 2-(1H-indol-3-yl)acetate (106aʹ) and methyl 4-(1H-indole-3-yl)butanoate (106bʹ) respectively. These esters were further converted to 2-(1H-indol-3-yl)acetohydrazide (107aʹ) and 4-(1H-indole-3-yl)butaneydrazide (107bʹ) respectively. Finally, the compounds (107aʹ) and (107bʹ) underwent a reaction with substituted carboxylic acids in the presence of POCl3 to produce the desired targeted compounds: 110aʹ, 111aʹ, 110bʹ, and 111bʹ. The synthesized compound yields were as follows: 110aʹ (62%), 111aʹ (55%), 110bʹ (57%), and 111bʹ (53%). The chemical structures of these synthesized compounds were partially characterized by using spectroscopic techniques like UV-Vis and FT-IR. The synthesized compounds were evaluated for their in vitro antibacterial activity test against four bacterial strains: E. coli, P. aeruginosa, S. pyogenes and S. aureus by the disk diffusion method. Among synthesized compounds, compound 111bʹ showed potent inhibitory activity against Gram-negative, E. coli with 11.57 ± 0.15 mm zone of inhibition compared to the standard drug tetracycline (13 ± 0.5 mm) at 150 mg/mL. The RSA of synthesized compounds were assessed through DPPH radical assay, revealing that compounds 111aʹ and 110aʹ demonstrated higher %RSA (91.83% and 89.9%, respectively) with IC50 values of 4.95 and 5.03, respectively, compared to the standard ascorbic acid of %RSA (87.5%) with an IC50 of 31.44 and than other synthesized compounds. Hence, the studies have indicated that all the synthesized compounds could be considered as potential candidates for further investigation in antibacterial and antioxidant research.
PHYTOCHEMICAL INVESTIGATION AND ANTIBACTERIAL ACTIVITY TESTS ON ROOT EXTRACT OF EUPHORBIA CANDELABRUM
(Hawassa University, 2024-06) KIFLE JILO JEGO
Euphorbia candelabrum is a medicinal plant that is known to be used for the treatment of various diseases such as coughs, tuberculosis, malaria, and wound healing and for treating various skin disorders in different communities. This study aimed to investigate the chemical constituents and characterize the compounds isolated from the root extract of Euphorbia candelabrum using UV-Vis and FT-IR spectroscopy as well as to test its antibacterial activity. Due to its medicinal importance, the plant material was collected from, the Sika kebele, Bule woreda, Gedeo zone, Southern Ethiopian region. The plant material was air dried and sequentially extracted with n-hexane, dichloromethane, dichloromethane/methanol (1:1 v/v) and methanol. Phytochemical screening of the dichloromethane, dichloromethane/methanol (1:1 v/v) and methanol crude extracts revealed the presence of alkaloids, flavonoids, phenols, glycosides, terpenoids, tannins, saponins and steroids, whereas the n-hexane crude extracts contained alkaloids, glycosides, terpenoids, steroids and saponins. The total contents of flavonoids, phenolics, alkaloids, and steroids in the dichloromethane/methanol (1:1 v/v) crude extract were 10.47 mg QE/g, 13.4 mg GAE/g, 1.426 mg AE/g, and 2.91 mg DE/g , respectively. The methanol extract contained 11 mg QE/g, 19 mg GAE/g, and 2.1 mg AE/g of extract for the total of flavonoid, phenolic, and alkaloid contents, respectively. Column chromatographic separation of dichloromethane/methanol (1:1 v/v) resulted in the isolation of three compounds (KJ-1, KJ-2 and KJ-3) and structure of the isolated compounds were not fully characterized due to lack of NMR instrument. The crude extracts and isolated compounds were tested against four bacterial strains in vitro (E. coli, P. aeruginosa, S. aureus and S. pyogen) using the disc diffusion method. The antibacterial activity tests revealed that the isolated compounds had greater activity than did the crude extracts. Notably, compound KJ-3 demonstrated the highest antibacterial activity against all tested bacterial strains than crude extracts and isolated compounds but slightly lower than that of the reference drug tetracycline. The present study indicated that the root of Euphorbia candelabrum could be a good source of compounds for the discovery of antibacterial agents because in vitro tests were carried out on several bacterial strains.
BIOSYNTHESIZED NITROGEN-ZINC-CODOPED COPPER OXIDE NANOPARTICLES FOR PHOTOCATALYTIC DEGRADATION OF METHYLENE BLUE
(HAWASSA UNIVERSITY, 2024-06) YOHANNES SHUKA JARA
Herein, nitrogen-zinc-codoped copper nanoparticles (N-Zn-CuO NPs) was successfully synthesized by using Pycnostachys Abyssinica Fresen plant leaf extract as a bioreducing and capping agent for the photocatalytic degradation of methylene blue under natural sunlight irradiation. Additionally, pure CuO NPs, N-CuO NPs, and Zn-CuO NPs were also biosynthesized for comparison. Characterization techniques of UV-Vis, XRD, SEM, FT-IR revealed that N-Zn-codoping narrowed the band gap (1.72 to1.07 eV), reduced the crystallite size (25 to11.23 nm), distortion of monoclinic crystal lattice (rhombus and diamond like shape with an average diameter of 2.25 µm to irregular shape with an average size of 2.75 µm), and towards redshift of the Cu-O characteristic peaks (617 to 529 cm-1 ) of CuO NPs, respectively, confirmed the successful incorporation of dopants into CuO NPs. The effects of key parameters on the photocatalytic degradation efficiency of all biosynthesised NPs were investigated. The optimal conditions with maximum degradation for N-Zn-CuO NPs were determined to be 3% dopant concentration for both N and Zn, 120 mg of photocatalyst dosage, pH of solution at 11, 20 ppm of Initial dye concentration and 30 minutes of reaction time. Photocatalytic activity towards methylene blue (MB) dye degradation under 30 minutes exposure to sunlight was 99.75% for N-ZnCuO NPs, outperforming pure CuO NPs (95.76%), N-CuO NPs (97.93%), and Zn-CuO NPs (98.26%) under optimal conditions. The enhanced photocatalytic performance of NZn-CuO NPs is attributed to their tailored optical properties, leading to improved charge separation and reduced recombination. Kinetic studies revealed a strong fit (R2=0.99799) with the BMG kinetic model for N-Zn-CuO NPs, indicating surface-mediated degradation of MB. Furthermore, the nanocatalysts exhibited excellent reusability and stability over four cycles. This finding highlights the potential of biosynthesized N-Zn-CuO NPs as highly efficient, simple, eco-friendly and sustainable solutions for the degradation organic pollutants.
PHYSICOCHEMICAL CHARACTERIZATION OF THREE WHOLE GRAIN TEFF CULTIVARS GROWN IN ENOR ENER MEGER WEREDA, GURAGHE ZONE, CENTRAL ETHIOPIA REGIONAL STATE, ETHIOPIA
(HAWASSA UNIVERSITY, 2024-06) FETENE BAYLIE
Enor Ener Meger wereda is one of teff [Eragrostis teff (Zucc.) Trotter] growing and producing wereda’s in Guraghe zone, Central Ethiopia Regional State, Ethiopia. However, there is no information regarding the chemical composition of ‘teff’ grown in this wereda. Thus, this study was conducted to generate information on the chemical composition (proximate and mineral content) of ‘teff’ grown in Enor Ener Meger wereda and compare the result among the selected whole grain ‘teff’ samples and with the national standards for ‘teff’ flour specifications. A total of 5.0 Kg of ‘teff’ grain composite samples for each type of ‘teff’ were collected from ten farmers selected randomly from two kebeles in Enor ener meger woreda and were analysed for their physicochemical composition and mineral content. The proximate composition of whole grain ‘teff’ flours was determined using Standard methods of analysis and Flame Atomic Spectrometer was used to measure minerals content of samples. The mean ranges of values for pH, moisture, total solids, total ash, crude protein, crude fiber, crude fat, total carbohydrate, and energy were 6.36–6.77, 10.78–14.19%, 85.80–89.22%, 1.73–2.53%, 9.64–10.94%, 2.08–2.60%, 2.39–2.57%, 67.92–72.58%, and 336.56–350.36 kcal, respectively for the three whole grain ‘teff’ samples. Similarly, the mean ranges of values for calcium, magnesium, copper, and manganese were 153.29–248.54 mg/Kg, 123.93–180.20 mg/Kg, 11.66–27.20 mg/Kg, and 45.47–170.27 mg/Kg, respectively for the three whole grain ‘teff’ samples. Results indicated that there were significant differences in most of the evaluated physicochemical composition and minerals content among the three whole grains ‘teff’ samples. The results showed that key whole grain ‘teff’ samples contains relatively high amount of protein, fat and fiber than white whole grain ‘teff’ flour samples. Furthermore, minerals such as Ca, Mg, and Mn were found to be the lowest in white whole grain ‘teff’ samples. This might suggest that key whole grain ‘teff’ varieties are nutritious than the white whole grain ‘teff’ varieties. However, key whole grain ‘teff’ varieties have lower market price and social values in the community to the contrary
PREPARATION OF BIOSORBENTS FROM JATROPHA CURCAS LEAF FOR THE REMOVAL OF MALCHITE GREEN FROM AQUEOUS SOLUTION
(Hawassa University, 2024-10) AYUB HAJI
Malachite green used in textile and dyeing industries is a common persistent pollutant in wastewater and the environment causing major hazards to human health and aquatic organisms. The main objective of the study was to prepare biosorbent from Jatropha curcas leaf for the removal of malachite green from aqueous solution. Biosorbent was prepared from Jatropha curcas leaf using chemical activation method. Characterization techniques including FTIR and SEM analysis of biosorbent was evaluated. The FTIR analysis showed the presence of phenols, aromatic compound, lignin, ketone and aldehyde on biosorbent surface and after adsorption spectra revealed the great interaction of malachite green with the surface functional group of biosorbent. SEM analysis revealed that biosorbent was irregular, porous and heterogeneous, and after adsorption shows that great affinity of malachite green on the surface of biosorbent. The removal percentage and adsorption capacities of malachite green from aqueous solution was 99.6% and 49.8 mg/g was obtained at optimal condition of pH 8, 10 mg/L of initial concentration, 0.2 g/L of adsorbent dosage, 90 minutes of contact time and 45 . Freundlich model was best fit for removal of malachite green from aqueous solution than Langmuir due to its higher correlation coefficients and lower mean standard error (MSE) (R 2 : 0.99993, MSE:0.000055). Pseudo second order was well fitted for the adsorption of malachite green from aqueous solution than pseudo first order due to its higher coefficients and lower sum square error (SSE) (R2 :0.99999, SSE: 0.000051). Thermodynamic analysis presented that the adsorption process of malachite green from aqueous solution was employed spontaneous process and endothermic reaction. These findings suggest that the use of biosorbent prepared from Jatropha curcus was cost-effective for the removal of malachite green from contaminated environment.
LEVELS OF SELECTED ESSENTIAL AND NON-ESSENTIAL METALS IN THE SOIL AND GINGER (ZINGIBER OFFICINALE) CULTIVATED IN KAMBATA ZONE, HADERO TUNTO WOREDA CENTERAL ETHIOPIA
(2024-10) BEYENE BADEBO BATAMO
Ginger is a common spice and condiment for many foods and beverage. Its extracts are widely utilized in the culinary, beverage, and confectionary industries for making product like liquors, biscuits , pickles, chutney, marmalade and ginger beer. The levels of essential (Ca, Zn, Cu, Co, Cr, Mn, and Ni) and non-essential (Pb) metals in ginger cultivated in four different sites of kembata zone Ethiopia and the soil where it was grown were determined by flame atomic absorption spectrometry. 0.5 g of oven dried ginger and soil samples were digested using 3 mL of HNO3 and 2 mL of HClO4 at 230°C for 2:30 h and a mixture of 6 mL aqua-regia and 2 mL H2O2 at 250°C for 3 h, respectively. The mean metal concentration (mg/Kg dry weight basis) ranged in the ginger and soil samples, respectively, were: Ca (874–1253, 801–1550), Zn (4.16– 7.1, 48–110), Cu (3.3–5.4, 8.4–13.3), and Mn (231–321, 527– 673), the other metals like Pb, Cr, Ni and Co were not detected in both the ginger and soil samples. There was good correlation between some metals in ginger and soil samples. This study revealed that gingers samples taken from sample site are good source of essential metals and free from toxic metal Pb, Cr, Co and Ni.
PHYTOCHEMICAL INVESTIGATION OF THE STEM BARK OF STEREOSPERMUM KUNTHIANUM
(Hawassa University, 2024-10) ABATIHUN SHITIE
The traditional medicinal system continues to play an essential role in health care, with about 80% of the world’s inhabitants relying mainly on traditional medicines for their primary health care. The genus Stereospermum is known to possess medicinal properties in every part of the plant. Stereospermum kunthianum is one of the medicinal plants that has been claimed to be used traditionally to treat several illnesses such stomachaches, toothache, snake bitze, gonorrhea, evil eyes, diarrhea, skin diseases, and headaches. This study was conducted to investigate “Phytochemical constituents of stem bark of Stereospermum kunthianum”. The stem bark (500 g) of Stereospermum kunthianum was extracted with n-hexane, chloroform/methanol (v/v, 1:1) and methanol solvent systems sequentially using maceration technique and resulted in 1.8 g, 9.8 g and 15 g crude extract respectively. Phytochemical screening was carried out by standard procedures and the result showed the presence of the classes of secondary metabolites such as alkaloids, tannins, saponins, steroids, flavonoids, phenols, glycosides, and terpenoids.The chloroform/methanol (v/v, 1:1) crude extract was subjected to column chromatography that resulted in three compounds coded as SK1,SK2 and SK3. The structures of the isolated compounds was partially characterized by generating UV and IR data,systematically interpreting the data,melting point and comparing the data with literature.The FTIR analysis revealed that SK1, SK2 and SK3 are in good agreement with solanidanes, α-amyrin and Betulin respectively
REMOVAL OF METHYLENE BLUE DYES FROMAQUEOS SOLUTIONBYUSING ACTIVATED CARBON PREPARED FROMSTEMPARTOFCROTON MACROSTACHYUS (BISANA)
(Hawassa University, 2024-10) HUSSIEN MAMA MIDASSO
In this study activated carbon was prepared from Stem part of Croton macrostachyus andutilizedas adsorbent to study its adsorption ef iciency towards removal of Methylene blue dye fromaqueoussolution. The AC was prepared by acid treatment and calcinated in muf le furnace at dif erenttemperature ranging from 400 0C to 700 0C. The prepared AC was characterized by usingFT-IRandscanning electron microscope (SEM).FT-IR results showed that dif erent functional groupslikehydroxyl, aldehydes, and carbon-carbon double bond functional groups were observed at dif erentwave numbers. The amount of MB dyes adsorbed was determined using UV-Vis spectrometeryat itsλ max of 664 nm. It was found that the adsorption of MB on adsorbent obeys the Langmuiradsorption isotherms. The Values of the equilibrium parameter ‘RL’ from the Langmuir isothermwas0.040. These results confirmed that the adsorption process of MB dye on the preparedActivatedcarbon is favorable.The ef ects of some working parameters like pH, dye initial concentration, temperature and contact time on the adsorption of MB dyes were also studied. The optimumconditions were maximum removal ef iciency occur was at dose of 0.1 gram, initial concentrationof10 ppm, contact time of 90 minutes, pH of 8 and temperature of 45 0C. The dye adsorptionwas foundto decrease with increasing initial dye concentration and the percentage removal of the dyeandtheamount adsorbed on the surface of the adsorbent both showed significant increase with increaseintemperature up to 45 oC. The ef ect of contact time on the percent removal of MBdyeshowedincreasing trend as the reaction time increase. It was observed that the pseudo-second-order kineticmodel fits better with good correlation coef icient and the equilibrium data fitted well withlangmuirmodel.
Phytochemical Analysis of The Stem Bark Extract of Eucalyptus globules Labill
(Hawassa University, 2024-10) KIDIST BEYENE BAYOU
The traditional medicinal system continues to play an essential role in health care, with about 80% of the world’s inhabitants relying mainly on traditional medicines for their primary health care. The genus Eucalyptus is known to possess medicinal properties in every part of the plant. Eucalyptus globules is one of the medicinal plants that has been claimed to be used traditionally to treat several illnesses such as stomachaches, toothache, snake bite, gonorrhea, evil eyes, diarrhea, skin diseases, and headaches. The aim of this study was to investigate the phytochemicals of the stem bark of Eucalyptus globules. The stem bark was chopped into small pieces, and air dried under shade, at room temperature. The complete air-dried stem bark was pulverized into fine powder. The powdered stem bark was extracted successively with three different solvents: hexane, CHCl3:MeOH (v/v, 1:1) and methanol using cold maceration method. The percentage yield shows 0.42%, 2.4%, and 3.22% of hexane, CHCl3:MeOH (v/v, 1:1) and methanolic extracts respectively. Phytochemical screening tests of the crude extracts of theCHCl3:MeOH (v/v, 1:1) and methanolic extracts revealed the presence of the classes of secondary metabolites namely alkaloids, flavonoids, phenols, glycosides, terpenoids, saponins, and tannins. The crude n-hexane extract showed the presence of phenols, cardiac glycosides, terpenoids, steroids, and saponins. The CHCl3:MeOH (v/v, 1:1) extracts were further fractionated with various composition of hexane:ethyl acetate and ethylacetate:methanol solvent systems which resulted in three compounds,EG-1, EG-2, and EG-3. The UV-Vis and IR spectral data of the isolated compounds were generated in addition to their melting points. The structures of the isolated compounds were partially illustrated because of the absence of NMR data. The experimental UV-Vis and IR spectroscopic data were interpreted and compared with literature in order to propose the structure and the identity of the compounds. Hence the isolated compounds EG-1, EG-2 and EG-3 were proposed to be chrysin (5,7-dihydroxyflavone), purpurin (1,2,4-trihydroxy 9-10 anthraquinone) and 1,2-Dimethoxy-6-methyl-9,10-anthraquinone ,respectively.
DETERMINATION OF SELECTED PHYSICOCHEMICAL AND MINERAL CHARACTERISTICS OF DRINKING WATER IN ANASORA DISTRICT, GUJI ZONE, OROMIA REGIONAL STATES, ETHIOPIA
(HAWASSA UNIVERSITY, 2024-10) DEREJE JANBOARARSO
Drinking water should be free unwanted constituent, contaminant, or impurity and fulfil quality requirements (desirable and permissible limits) recommended national and international organizations. This study was done to determine the levels of selected physicochemical parameters (temperature, pH, Electrical Conductivity, Total hardness, Total Alkality, and chloride), and minerals such as (Ca, Mg ,Cr and Pb), trace elements (Cu, Mn, Ni, and Co) in drinking ground water samples sampled from selected Kebeles such as Bube Korsa, Hiyo Komele, and Irba Buliyo of Ana Sora district, Guji zone, Oromia regional state, Ethiopia. The temperature, pH, electrical conductivity, and TDS were measured using an AD8000 pH/mV/EC/TDS/Temp meter; TH, TA, and chloride were determined by titration method, while the mineral content was determined by flame atomic absorption spectrometry (FAAS). The average values of the physicochemical parameters investigated in this study were found to be in the range: temperature (20.8 – 23.1) °C, EC (3.7 – 23.7) 𝜇S/cm, TDS (8.5 – 12.8) mg/L, TH (14.7 – 42.4) mg/L, TA (23.3 – 38.3) mg/L and chloride (2.3 – 3.8) mg/L. The average concentrations of the minerals were found to be in the range of temperature: Ca (2.32 – 9.62) mg/L, Mg (11.9 –24.6) mg/L, and Cu (0.13 – 0.30) mg/L. Metals such as Mn, Ni, Co, Cr, and Pb were found to be below the detection limit of the instrument. The accuracy of the method of recovery experiment the analysis was evaluated by analyzing the digest of the spiked samples. The recoveries of the metal were in the range of 96.0to 110.0%.OneWay-ANOVA analysis showed that there were significant variations (p < 0.05) in the physicochemical parameters and metals investigated among the drinking groundwater samples. However, all the values of the physicochemical parameters investigated were found to be within the acceptable standard specified in Compulsory Ethiopian Drinking Water Specifications. Therefore, the drinking ground water supplied to the community in Ana Sora district was deemed to be safe for human consumption according to the selected parameter and, mineral set as standard.
REMOVAL OFHEAVY METALS FROM RIVER WATER USING ACTIVATED CARBON OF EUCALYPTUS GLABULUS BARK (BAHIRZAF)
(HAWASSA UNIVERSITY, 2024-10) YIDAGNU FEREDE
Heavy metal pollution has become one of the most serious environmental problems nowadays. The removal of heavy metals from the environment is of special concern due to their persistence. Batch experiments were conducted to test the ability of activated carbon for the removal of lead, nickel, copper and zinc from water Heavy metal pollution in the marine system has become a seriousthreattodayandofgreatenvironmentalconcernastheyarenon-biodegradableandthuspersistent. Eucalyptus glabulus bark locally named as ‘Bahirzaf’ collected aleta wendo town from area around were used for activated carbon preparation. Dumps and polluted water Activated carbon wasprepared synthesized from bio-waste materials of the plant Eucalyptus barks. This work deals with the preparation of activated carbon from Eucalyptus leave store move heavy metal ions: such as Cu(II),Pb(II),Zn (II),and Ni(II)from aqueous solution. Chemical activation of the carbon was done by H3PO4, H2SO4, KOH and Characterization includes pH. The optimum temperature used to prepare activated carbon of Eucalyptus leaves was 500 oC while the optimum pH value and contact time for activated carbon of Eucalyptus leaves was determined as6and60minrespectively.Theoptimumenvironmentsforadsorbentsdosewasdetermined0.041 g in 25 ml solution. Thermodynamic analysis asserted endothermic and spontaneous nature of the system with involvement of chemical adsorption process. Equilibrium data were represented better by the Freundlich model than the Langmuir model which describes a multilayer adsorption.
ASSESEMENT OF THE LEVEL OF HEAVY METALS IN DIFFERENT VARIEETIES OF KHAT (CATHA EDULIS) AND SUPPORTING SOIL SAMPLES COLLECTED FROM TULLA AREA, SIDAMA REGION; ETHIOPA
(2024-11) GETAHUN MENGIST GELLA
Heavy metal pollution of the environment has been a global concern due to its acute and chronic health effects. The consumption of contaminated food and beverages is among the major route of exposure. Khat (Catha edulis) is one of the major cash crops that are widely cultivated and consumed as stimulant in the study area (Tulla Sidama regional state).This work focuses on the physicochemical analysis and determination of selective heavy metals (Cu, Co, Ni, Cr and Pb) concentration in chewable parts of the leaves of the selected Khat varieties (Nole, Dume and Megala) and its support soil samples. Samples were randomly collected from the selective kebeles of the study area and digested using mixture of acids. Analysis of the physicochemical parameters (pH, electrical conductivity and ash content) was carried out by standard method. The determination of the heavy metals was carried out using Flame Atomic Absorption Spectroscopy (FAAS). The physicochemical analysis showed pH (6.21-6.82), electrical conductivity (1.42-1.86), and ash content (1.72-2.17) in soil samples and pH (5.93-6.43), electrical conductivity (1.17-1.54), and ash content (0.63-0.93) in khat samples. The heavy metal analysis showed concentration of Cu, Ni and Co to be 4.33-4.93mg/kg, 2.52-3.26mg/kg and 1.84-2.85mg/kg respectively in khat samples. The levels of these metals in the corresponding soil samples were (8.54-9.96mg/kg), (3.67-4.95mg/kg) and (3.37-4.85mg/kg for Cu, Ni and Co respectively. Pb and Cr were not detected in soil and khat varieties samples. Among the analyzed heavy metals Cu was detected relatively at the highest concentration followed by N and Co in both soil and Khat samples. These findings indicated a positive correlation between the levels of the heavy metals in the soil and the Khat samples. Although Pb, Cr, Cu and Ni were detected below the permissible level, Co was detected above the permissible level stipulated by WHO. Therefore, it can be concluded that continuous consumption of Khat as stimulant might lead to health risks associated with heavy metals.
THE EFFECT OF IRRIGATION AROUND ZIWAY ON HEAVY METAL CONTENT OF MAIZE GRAIN AND SOIL
(Hawassa University, 2024-11) SILESHI TEFERRA
The aim of the current study was to determine the metallic concentration of maize of irrigated versus rain fed and soil of irrigated versus rain fed and the water used for irrigation. This is to investigate the influence of irrigation on the concentration of heavy metals in the maize grains and soil. This was done by comparing with rain fed farms. The concentrations of copper (Cu), zinc (Zn), chromium (Cr), nickel (Ni), and lead (Pb) in acid digested sample were determined using flame atomic absorption spectrometry. A composite purposive sampling method was used to collect samples from sample site of ziway city, Ethiopia. Microsoft Excel was used for Descriptive statistical analysis of the results and one way ANOVA was employed to compare the mean difference of heavy metals concentration between irrigated and rain fed. In maize samples (rain fed and irrigated maize) the mean concentrations of Pb, Cr, Ni, Cu and Zn were (0.42 – 1.25) for rain fed and irrigate maize, (not detected (nd) – 0.42) for rain fed and irrigated maize, (0.62 –0.93) for rain fed and irrigated maize, (10.8 – 12.3) for rain fed and irrigated maize and (20.23 – 24.3) for rain fed and irrigated maize. In soil samples mean concentration of Pb, Cr, Ni, Cu and Zn were in the range of (9.46 – 12.36) for rain fed and irrigated, (4.4 – 5.36) for rain fed and irrigated, (4.3 – 6.4) for rain fed and irrigated, (56.4 – 66.3) for rain fed and irrigated and (74.26 – 86. 35) for rain fed and irrigated. The mean concentrations of metals in water used for irrigation were (mg/L) of Pb (0.24), Cr (0.065), Ni (0.051), Cu (1.23) and Zn (0.92) in the irrigated water samples were above the limit set by US EPA (2004). The study show that irrigated (maize and soil) contained higher concentration of heavy metals and were above the limit set by US EPA which show that it was contaminated and would be unsave for human consumption.
PHYSICOCHEMICAL CHARACTERIZATION, PROXIMATE ANALYSIS AND DETERMINATION OF SELECTED HEAVY METALS IN COW’S MILK AND COW’S FEED “ATELLA” SAMPLES COLLECTED FROM ARSI NEGELLE TOWN, OROMIA REGION; ETHIOPIA.
(Hawassa University, 2024-11) TAJURA USMAN
Arsi Negele, also known as NegeleArsi, is primarily known for its production of Areki,a traditional alcoholic beverage, and its byproduct atella, which is widely used to feed cows to enhance milk production. However, concerns about heavy metal contamination from agricultural practices associated with Areki's raw materials have emerged, highlighting potential health risks linked to cow's milk and feed in the area. This study focuses on physicochemical characterization, proximate analysis and determination of selected heavy metals (Cr, Zn, Cu, Ni, Fe, and Pb) in milk and atella samples. Samples of milk and atella were collected purposively from five sites: meja kiltotasefar, kiltu demasefar, melka shayitsefar, Agip sefar, and mobile sefar. In ArsiNegelle town, and homogenized. The physicochemical properties and proximate analyses were performed by following the AOAC method. The concentrations of the heavy metals were analyzed using Flame Atomic Absorption Spectrometry (FAAS). All the samples were analyzed in replicates, and the mean values are presented. The obtained results showed that the (temperature, pH) were (20.3 ± 0.26, 6.74 ± 0.01) for the composite milk sample and (20.7 ± 0.01, 4.07 ± 0.02) for atella sample. The results of proximate analysis such as moisture, dry matter, crude protein ,crude fat, crude fiber, total ash, carbohydrate and gross energy contents of milk samples were 78.5 ± 0.486 % , 3.84 ± 0.03 %, 4.53 ± 0.251 %,3.35 ± 0.02 %,1.7 ± 0.1 %,0.436 ± 0.015 %, 7.23 ± 0.02 % and 64.34 ± 0.023 kcal/g, respectively. On the other hand, the respective mean values of proximate analysis of atella sample were 11.36 ± 0.20 %, 17.56 ± 0.01 %, 14.7 ± 0.2 %, 11.36 ± 0.20 %,, 17.56 ± 0.01, 14.7 ± 0.2 %, 42.36 ± 0.23 % and 276.71 ± 0.23 kcal/g respectively. From the analyzed metals Pb, Cr and Ni were not detected whereas the mean concentrations of Fe, Cu, and Zn were in the range of (0.037 – 1.363), (0.0983 – 0.853), and (0.926 – 0.971) mg/L respectively for the (milk, atella) samples. While the physicochemical and proximate analysis reinforced the claims of the traditional community that atella is nutritious feed for cows as evidenced by the proximate composition of milk. Although the levels of the heavy metals in both atella and milk samples were in the permissible range as stipulated by WHO, the study further revealed implications of carryover of the heavy metals from the cow’s feed atella to the milk.