Department of Chemistry

URI for this collectionhttps://rps.wku.edu.et/handle/987654321/2335

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SYNTHESIS AND CHARACTERIZATION OF MORINGA OLEIFERA WITH REDUCED GRAPHENE OXIDE NANOCOMPOSITE FOR ADSORPTIVE REMOVAL OF IRON FROM GROUND WATER
(Wolkite University, 2023-01-30) FELEKE GUADIE
Treatment of potable ground water in rural areas is still a serious problem in Ethiopia. This studywas conducted to investigate low-cost, environmental friendly and innovative composite adsorbent(rGO/MO) for the removal of elevated ferrous iron (Fe2+) from three randomly selected shallowwell water samples. All water samples were analyzed by different parameters like pH, temperature,electrical conductivity, turbidity, TDS, TSS, hardness, chlorides, alkalinity and Fe2+Concentration. The results of the study were ranged as pH (6.52-–7.22), Temperature (21.3–22.7 ℃), E.C (76.8–151.3 µS/cm), turbidity (15–22 NTU),TDS (79.2–121.3 mg/L), TSS (50–100mg/L), hardness(120–280 mg/L), chlorides(93–125 mg/L), alkalinity (200–550 mg/L) andFe2+(0.62–0.66 mg/L). The values of most of the parameters such as pH, conductivity, temperature,TDS, hardness, and chloride content were within the permissible limit of WHO and EEPA.However, the concentration of Fe2+ was above the maximum permissible limit set by WHO.Similarly, the values of physicochemical parameters such as turbidity, TSS, and alkalinity wereabove the acceptable range for drinking water limit set by WHO and EEPA. Thus, the resultshowed that the potable ground water collected from rural areas pose a risk to human healthunless a proper water treatment system is implemented. The investigated adsorbents (MO, rGO,and rGO/MO) were characterized by FTIR, SEM, XRD and UV-Visible techniques. An adsorptionresults showed remarkable adsorption capacity (qmax) of 44.6 mg/g as obtained from theexperiment. The adsorption efficiency of rGO/MO adsorbent for elevated ferrous iron removal wasaffected by parameters like initial metal concentration, contact time, pH, and adsorbent dose. Thehighest adsorption efficiency was observed (99.2 %) at pH 9. The optimum contact time for theadsorption process was found to be at 50 minutes. The amount of Fe2+ ions adsorbed decreaseswith increasing in initial metal ion concentration. FT-IR data indicated that the adsorption ofmetal ions occurs on the surface of rGO/MO powder as the main functional groups that areresponsible for metal ions binding are involved in the process. The Langmuir isotherm data Fe2+has good fit with the experimental data (R2=0.994) than Freundlich isotherm data Fe2+(R2=0.979)
CHEMICAL DEPOSITION OF POLYANILINE ON THE SURFACE OF MORINGA OLIFERA SEED FOR WASTEWATER TREATMENT
(Wolkite University, 2023-06-19) AYANSA FIKADU G/MARIAM
Water technology advancement coupled with environmental concern, increasing water demand, and the living standards of society led to the technology that provides clear water to the ecosystem. This study was give best alternative that surface modification of PANI on MO in which low-cost, effective, and environmentally friendly adsorbents new and innovated for water treatment technology. Thus, PANI/MO was synthesized by in situ oxidative polymerization of aniline on moringa olifera seed for wastewater treatment applications and study the physico- chemical parameter of wastewater generated from Enamor Woreda, Gurage Zone, SNNPR, Ethiopia. The values of most of the physicochemical parameters, and heavy metals were above the acceptable range for wastewater discharge limits set by WHO. The correlation coefficient of physico-chemical parameter between the four wastewater sampler was strong, and moderate correlation between all parameter(TDS,EC,TSS, pH, TA, and TH), while weak correlation between turbidity TDS, EC, TSS, pH, TA, TH, and Temp. The prepared nano-composites were characterized by powder XRD, FT-IR, UV spectroscopy and conductimeter. SEM and XRD studies reveal that the crystal structures of embedded MO were amorphous with semi-crystalline, while PANI, PANI/MO nanoparticles distorted and become porous with polycrystalline. Vibrational spectra analysis confirms that adsorbed PANI nanoparticles on the surface of MO acts as a compensator for positively PANI nanoparticles in the formation of PANI/MO nano composites. UV-visible spectroscopy showed that PANI/MO has a smaller band gap compared with MO; this implies that PANI/MO has a higher probability of absorbing light, being optically active, or being chemically reactive. The experiment found that the PANI/MO composites had a best adsorption capacity for copper (10.01 mg/g) and lead (23.01 mg/g) in simulated wastewater solutions. When all parameters were optimized (pH at 5, contact time at 30 minutes, temperature at 250c, and 2 gram of PANI/MO) removal adsorption efficiency for Pb2+ (99%), and Cu2+ ions(97.77%). The Freundlich isotherm data for Cu2+ and Pb2+ have a good fit with the experimental data (R2 = 0.99 and 0.98), respectively. Cu2+ and Pb2+ Langmuir isotherm data (RL=0.18 & 0.19). The pseudo second order kinetic isothermal was more fit with physic-sorption at (R2=0.99 for Cu2+ and R2=1 for Pb2+ ). The PANI/MO composite shows antibacterial activity against the bacterial species.
IMPACT OF CLASS SIZE ON ACADEMIC ACHIEVEMENT IN CHEMISTRY AT PUBLIC SECONDARY SCHOOLS OF SEBETA AWAS WOREDA, OROMIA REGION
(Wolkite University, 2024-01-01) FIKADU EJETA TUFA
This study assessed the impact of class size on academic achievement of chemistry in secondary schools in Sebeta Awas Woreda. The study used descriptive survey research design whereby both qualitative and quantitative approaches were the basis of data collection and data analysis. A sample of three public secondary schools was selected using the simple random sampling technique. The population of the study comprised all the eight chemistry teachers, three principals, one vice principal, one supervisor and one hundred sixty-two students. Data was collected using questionnaire, interview, observation and document review and the analysis of the questions was done using descriptive statistics, frequency, percent, mean and standard deviation. The research questionnaires were validated by advisor, supervisor and two senior science teachers in secondary schools of Tefki and Awash Melka and the pilot-test method was used to ascertain its reliability with coefficients of 0.92 for the teachers’ questionnaires and 0.98 for the students’ questionnaires. The findings revealed that class size had negative impact on academic achievement in chemistry. It was also observed that class size has psychological and social impact on students’ academic achievement and negatively influence teacher’s quality of work and assessment, whereas, they are improved by small class size. It was recommended, among other suggestion, that governments should prioritize the construction of more building of additional classrooms and the employment of more teachers to provide solution to the problem of high students-teachers ratios. The students-teacher ratio should be 45:1 as suggested by National Policy on Education as against 70-112 and above as discovered from the study. As a long-term measure, the government should increase budget allocation to improve schools’ infrastructural facilities.
ASSESSMENT OF PHYSICOCHEMICAL PROPERTIES AND HEAVY METAL CONTAMINATION IN HORA HARSADE WATER, BISHOFTU, EAST SHOA ZONE, OROMIA, ETHIOPIA.
(Wolkite University, 2024-01-01) Naol Assefa
Hora is a type of ground natural mineral water which are used as a source of mineral supplement for livestock. It has the medicinal value to protect the animals from different diseases and useful for their health growth. The aim of this study was to assess Physicochemical Properties and Heavy Metal Contamination in Hora Harsade Water, Bishoftu, East Shoa Zone, Oromia, Ethiopia. The Hora water samples were analyzed for physicochemical parameters and heavy metal concentration using a DR/2400 UV-vis spectrophotometer, flame photometry and ICP OES by following standard methods and laboratory procedures. The experimental procedures were set according to the international drinking water standards set by American Public Health Association (APHA). The study was carried in Winter, Spring and Summer, 2024. A total of 15 physicochemical properties and 5 heavy metal concentrations were analyzed in order to understand the characteristic and quality status of the Hora natural mineral water with temperature, pH, turbidity, electrical conductivity (EC), total dissolved solids (TDS), total suspended solids (TSS), Total solids (TS), Total Alkalinity (TA), Total hardness (TH), Dissolved solids (DO), Na, K, Ca, Mg, Chloride ion (Cl-); and heavy metals like: Cu, Fe, Zn, Mn and Cr. The results were evaluated with national (NDWQS, 2013) and international (WHO, 2018) drinking water standard values for human and livestock. The recorded mean concentration of temperature 19.37±0.15 0C higher than 15 0C WHO, TSS (91.33±1.15 mg/L) which is above WHO (30 mg/L), Na (318.39±11.35 mg/L) is above 200 mg/L (NDWQS and WHO), and Mn (0.56±0.05 mg/L) which is above permissible limits of NDWQS (0.5 mg/L) and WHO (0.1 mg/L). All the rest listed above properties of water were observed within the recommended permissible limits of CES and WHO standards that agreed with domestic water quality level. Based on the current study result the Hora Harsadee spring water is suitable for domestic purposes after moderate treatment of temperature, TSS, Na & Mn. For more detail quality monitoring, other physicochemical, toxic metals and microbial analysis have to be done in order to have a broader picture of those spring water quantity.
FACTORS AFFECTING 10TH GRADE STUDENT ACEDAMIC PREFORMANCE IN CHEMISTRY
(Wolkite University, 2024-01-01) URGESSA OLANA TERFA
Chemistry has been identified as a very important school subject and its importance in scientific and technological development of any nation within the context of science education. This study aims at investigating factors that influence performance of Chemistry in Fincha secondary schools in Abay Chomen District of Oromia regional state, Ethiopia. The data was collected using questionnaires to both students and teachers; class observation schedule and interview to principal. Descriptive and inferential statistics was used to analyze the collected data. The descriptive survey was employed to identify students attitude, assess the professional qualification of teachers; and analyze the teaching and learning methods used and learning resource needed in teaching the subject. The inferential statistics was used to support these descriptive survey of the study. The finding of the result revealed that, attitude of students towards chemistry; professional qualification of Chemistry teachers; teaching and learning methods used in teaching Chemistry subject and teaching and learning resources needed in teaching of Chemistry subject were the factors identified that hinders the students’ performance toward the subject. Moreover, the result indicate that, eventhough majority of the students were very positive toward learning Chemistry subject, their performance is far below average and they seem to score low grade in Chemistry subject. Therefore, chemistry teachers should use student centered method of teaching, the school should strive to provide adequate resources to increase students’ performance in chemistry subject in the study area and teachers should organize symposium to sensitize students on the practical applications related to the subject and carrying out continuous evaluation test were recommended.
Green Synthesis, Characterization and Antibacterial Activity of Copper Nanoparticle from Xanthium Strumarium L. (Deha-Nikel) Plant Leaf Extract
(WOLKITE UNIVERSITY, 2024-04) Temesgen Alem Tsegaw
The green nanotechnology is generating interest in researchers for the synthesis of nano particles a simple, cost-effective and eco-friendly manner. This research is focused on the bio-synthesis of copper nanoparticles (CuNPs) using Xanthium strumarium L. plant extract. The biomolecules present in Xanthium strumarium L. plant extract act as self-reducing and stabilizing agents. The copper nanoparticles were synthesized by the addition of 100 mL of the aqueous plant leaf extract with 400 mL of copper nitrate solution (0.02M). The biosynthesized CuNPs were characterized by using UV-Vis analysis, Fourier Transform Infrared analysis (FTIR) and X-ray diffraction analysis (XRD) analysis. The maximum absorbance, λmax, was found to be 672 nm for CuNPs due to surface Plasmon resonance. The presence of important functional groups associated with biomolecules is well characterized by Fourier Transform Infrared spectroscopy (FTIR). The X-ray diffraction pattern showed the formation of purely crystalline nature of CuNPs with face-centered cubic geometry and the average crystalline size is found to be 26.88 nm. The antibacterial activity of the synthesized CuNPs and Xanthium strumarium L. plant leaf extract was established using both Gram-positive bacteria (Staphylococcus aureus) and Gram negative bacteria (Escherichiacoli, Klebsiella pneumoniae and Pseudomonas aeruginosa) by using agar well diffusion method. The synthesized CuNPs have strong anti-bacterial activity against gram-negative bacteria as compared to gram-positive bacteria
A CASE STUDY AT BURKA SEBETA 10 TH GRADE AND BURKA, SEBETA 12TH GRADE SECONDARY SCHOOL AT SEBETA SUBCITY SHEGER CITY OROMIA ETHIOPIA.
(Wolkite University, 2024-05-01) BACHA DEBELE CHALA
Chemical bonding is a topic that students commonly find abstract and problematic and for which they develop a wide range of misconceptions . Thus, chemical bonding is considered as difficult topic and students had misconception about bond polarity, intermolecular force, intramolecular force, the octet rule, conductivity, Solubility shapes and lattice energy. The purpose of this study was to identify the major misconceptions of grade 12 and 10 students’ on the chemical bonding and to identify the sources of these misconceptions. The nature of the study is a descriptive method. Participants of the study were 67 grade 12 students and 75 grade 10 students. The FTMCT was developed after their prior conceptions about the selected topics of the study were collected from students through review of related literature, observation of lessons on chemical bonding, common mistakes of focus class students during different assessment techniques (answering class tests) and individual interview questions with volunteer students. Data was collected by using FTMCT and Interview questions were employed to gather the relevant data. Data was analyzed by using Statistical Package for the Social Science program (SPSS). The results from SPSS (bivariate and reliability analysis) showed that average value of reliability coefficient and correlation between 1 st tier and 2nd tiers, 3 rd tiers and 4 th tiers, 2nd tier and 4 th tier were .99, .75, .68, .67 of grade 12 students and .96, .73, .79, .74, of grade10 student respectively. The significances also shown that chemistry daily experiences, text books, language difficulty and chemistry instructional methods were the major source of students’ misconception about chemical bonding. The result showed that the majority of the students had high level of misconceptions about chemical bonding. In this study the common misconceptions were identified on chemical boding which was categorized into: bond polarity, solubility, intermolecular force, intramolecular force, the octet rule, shapes, conductivity and lattice energy.
TEACHER AND STUDENT PERCEPTIONS TOWARD PRACTICAL ACTIVITY IMPLEMENTATION IN CHEMISTRY TEACHING AND LEARNING IN SOME SELECTED SECONDARY SCHOOL
(Wolkite University, 2024-07-01) NAOL NAMOMSA DABA
This study investigates the perceptions of teachers and students regarding the practical implementation and activities in chemistry classrooms. The study aimed to explore the factors influencing the effectiveness of chemistry education and identify strategies to improve student engagement and learning outcomes. To achieve these objectives, data were collected from three secondary school (Kolobo, Talacho and Suba) students, teachers and directors. In doing this study, quantitative and qualitative research methods and descriptive survey design were used. Stratified random and purposive sampling was used in the selection of study participants. The data were obtained through questionnaires, observation, and interviews. Based on the analyzed data, the findings of the study revealed that students, teachers and directors perceived that chemistry practical courses (experiments) are relevant to students learning. Additionally, the findings of this study also showed that despite its relevance, the practice of laboratory work is very low. Furthermore, the lack of resources (such as laboratory equipment), the lack of time to practice laboratory work, and students’ lack of engagement in laboratory activities were the major factors that affected the implementation of laboratory work. The study provides valuable insights into the importance of effective communication, hands-on experiments, and real-world applications in chemistry education. Finally, it recommends that this study can inform curriculum development and instructional practices to enhance student learning and satisfaction in chemistry classrooms. It provides educators can implement strategies to enhance the learning experience in chemistry classrooms.
DENTIFYING AND MINIMIZING STUDENTS’ MISCONCEPTIONS IN CHEMICAL BONDING: THE CASE OF GRADE 9 STUDENTS IN KUTERE SECONDARY SCHOOL, SILTE ZONE, CENTRAL ETHIOPIA, ETHIOPIATHE CASE OF GRADE 9 STUDENTS IN KUTERE SECONDARY SCHOOL
(Wolkite University, 2024-09-01) HASSEN MAHMUD ALI
Children do not come to school as a “tabula rasa, but rather with knowledge gained from different sources and through daily life. These different sources can help or hinder learning. This situation is said to be misconception. The main purpose of this study was to identify and minimize students’ misconceptions about chemical bonding. The study was carried out in Kutere Secondary School in Silte Zone, Central Ethiopia with special reference to grade 9 students’ focus. Descriptive survey, especially a case study was employed to address the problem. To conduct this study 72 students were selected through stratified sampling technique from the total population of 360 students. To achieve the objectives of the study employed data gathering tools were the conceptual understanding tests (pre-and post-test) in the chemical bonding topic. Each question in the conceptual understanding test was designed to previous students’ knowledge and understanding about chemical bonding. All data collected were analyzed quantitatively. The study described the causes for these misconceptions. These were students’ personal experience, inappropriate use of laboratory, misinformation, inattentiveness, selective attention, and unevaluated text books. Replacing those misconceptions with scientifically accepted conceptual views is necessary and efforts should be made to create awareness continuously for students, teachers, school principals and educational experts. Conducting training and different workshop with those concerned bodies is more advisable to increase the understanding and to avoid (minimize) misconceptions in chemical bonding. Thus, to improve the situation, it is recommended that every educator should be aware of students background, daily life experience, pre conceptions before providing lessons on chemistry teachers should spend more time to produce more conceptual talk about the topic to bring conceptual understanding, different instructional methods should be applied to support conceptual understanding of chemical bonding.
THE EFFECT OF ACTIVE LEARNING METHOD ON GRADE TEN STUDENTS IN THE ACHIEVEMENT OF CHEMISTRY: THE CASE OF ROMAN DEGA SECONDARY SCHOOL, KEDIDA GAMELA, KAMBATTA ZONE, CENTERAL ETHIOPIA REGION, ETHIOPIA
(WOLKITE UNIVERSITY, 2024-12) SEWUNET SAMUEL WANORE
Active learning requires students to do meaningful learning activities and think about what they are learning. This study aimed to investigate the effect of an active learning method on Grade 10 students in the achievement of Chemistry. The research was conducted at Roman dega Secondary School, kedida Gamela, Central Ethiopia Region. For the study purpose, a quasi-experimental design was employed. By using simple random sampling technique, 72 students were selected as a sample size from a total population of 360. Also 7 chemistry teachers, 3 the school principals and 1 supervisor were included in the study .A stratified sampling technique was used to maintain the proportional allocation of students from each section. The sampled students were assigned to two groups: experimental (N (exp) = 36) and control (N(con) = 36). The experimental group received instruction with active learning methods such as group discussion, question and answer, problem solving, experimental and visual-based learning. In contrast to that, the control group was taught with the traditional lecture method from the same chapter of "Energy Change and Electrochemistry" by the same teacher. The application took seven weeks. At the beginning of the first week, a pretest was administered for both groups. A post test was given for both groups at the end of the seventh week. To ensure the validity of the tool, the test was presented to the study advisor and four experienced high school teachers. The data obtained was analyzed using SPSS version 20. A T-test was used to test the statistical significance of the hypothesis generated in the study. The significance level of the results was tested at alpha = 0.05 significance level. Results showed that there was a significant difference between the means of experimental group pretest and post test ( p ≤ 0.05) in the achievement of chemistry. But there was no significant difference between the means of the control group pretest and post test after intervention (P > 0.05). Questionnaires were also administered before and after the intervention. The findings of the study revealed that incorporating an active learning approach in chemistry enhanced the learning achievement of 10th grade students. In light of the obtained results, the researcher recommended the utilization of an active learning method in teaching chemistry so as to enhance students’ achievement in chemistry and positive perceptions towards chemistry.
Green Synthesis and Characterization of Magnetite (Fe3O4) nanoparticle using Khat (Catha edulis) plant leaf extract for the removal of methylene blue dye from aqueous solution
(Wolkite University, 2025-01-01) Metaalem Shibabaw
This study synthesized magnetite nanoparticles using an aqueous extract of Catha edulis leaf in a green manner. The effectiveness and ability of the resultant nanoparticles in removing Methylene Blue dye were also assessed. Utilizing SEM, FTIR, P-XRD, and UV-DRS spectroscopy, the produced nanoparticle was examined. According to the XRD data, the average particle size of the produced magnetite NPs was 9.05 nm. The outcome confirmed that Fe3O4 nanoparticles had absorbance maxima at 364 nm, and for samples of produced magnetite nanoparticles, various functional groups were discovered to be connected with the plant extract. The produced Fe3O4 NPs displayed a variety of morphologies and microstructural features for Fe3O4 nanopowder. In addition, the SEM images of the Fe3O4 NPs showed that the nanoparticle morphology was uniform in structure. Using the batch adsorption method, the effectiveness of the adsorbent was assessed by adjusting several parameters, including pH (3–9), adsorbent dose (20–80 mg), initial adsorbate concentration (5 mg/L–20 mg/L), and room temperature contact time (30–90 minute). Optimal removal (99.25%) was achieved at pH 9, using 20 mg of adsorbent, 50-minute contact time, and an initial methylene blue concentration of 5 mg/L. The Langmuir isotherm model and pseudo-second-order kinetics model best described the experimental data (R² ≈ 1). This research suggests that the biosynthesized Fe₃O₄ nanoparticles show significant potential in the removal of methylene blue dye from aqueous solutions.
GREEN SYNTHESIS OF PANI/MAGNETITE ADSORBENT USING CROT ON MACROSTACHYUS LEAF EXTRACT FOR REMOVAL OF RHODAMI NE BLUE DYE FROM AQUEOUS SOLUTION.
(Wolkite University, 2025-01-01) YESHIWAS DAGNAW YEWALA
In this study, a green synthesis approach was employed to create adsorbent consisting of polyaniline (PANI) and magnetite (Fe₃O₄) nanoparticles using an aqueous extract of Croton macrostachyus leaves. To characterize the structural, chemical, and optical properties of the synthesized materials, several analytical techniques were employed. The XRD results indicated that the average particle size of the PANI/Fe₃O₄ adsorbent was approximately 14 nm, suggesting that the material consisted of nanoscale particles, which is crucial for improving the surface area and reactivity of the adsorbent. UV-DRS analysis revealed that the nanocomposite exhibited broad absorbance peaks between 700 and 800 nm. FTIR spectroscopy confirmed the presence of functional groups corresponding to PANI/Fe₃O₄, PANI and Fe₃O₄, and the phytochemicals in the Croton macrostachyus leaf extract. The adsorptive efficiency of each material was evaluated under varying experimental conditions, such as pH, adsorbent dose, contact time, and initial dye concentration. The results showed that the optimum conditions for dye removal occurred at a pH of 10, an adsorbent dose of 80 mg, a contact time of 50 minutes, and an initial dye concentration of 10 mg/L. Under these conditions, the dye removal efficiencies were 91.22% for PANI, 96.97% for Fe₃O₄, and 99.91% for the PANI/Fe₃O₄ adsorbent, demonstrating exhibited superior dye removal performance. To further understand the adsorption behavior, adsorption isotherm models were applied. The results indicated that the adsorption of Rhodamine Blue dye onto all three adsorbents (PANI, Fe₃O₄, and the nanocomposite) was best described by the Langmuir isotherm, suggesting that the adsorption occurred via a monolayer adsorption process with uniform adsorption sites. In contrast, the Freundlich isotherm, which models heterogeneous adsorption, did not fit as well, indicating that the adsorption sites on the materials were relatively uniform. Additionally, the adsorption kinetics were found to follow the pseudo-second-order model, suggesting that the rate-limiting step of the dye removal process was chemical adsorption. The findings from this study underscore the potential of the green-synthesized PANI/Fe₃O₄ adsorbent as a highly effective and environmentally friendly adsorbent for the removal of organic dyes from wastewater.
Green Synthesis of Fe-doped zinc oxide Nanoparticle for Removal of Methylene blue dye from Aqueous Solution
(Wolkite University, 2025-01-10) Wondimlebesku Delelegn Haile
In this study, Zinc oxide (ZnO) and iron-doped zinc oxide (Fe-doped ZnO) nanoparticles were synthesized using a green sol–gel method, utilizing Justicia Adhatoda plant leaf extract as a reducing agent. The aim was to investigate the potential of these nanoparticles as adsorbents for the removal of methylene blue dye, a toxic effluent commonly found in wastewater from textile industries. The synthesized materials were thoroughly characterized using various techniques: X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and UV-visible (UV-VIS) spectroscopy. XRD analysis confirmed that both ZnO and Fe-doped ZnO nanoparticles exhibited a hexagonal wurtzite crystal structure, with good crystallinity and phase purity. The average particle sizes were found to be 24 nm for pure ZnO and 20 nm for Fe-doped ZnO, indicating that doping with iron slightly reduced the particle size. FT-IR analysis revealed key absorbance peaks corresponding to functional groups from the plant extract, confirming the involvement of the plant's organic compounds in the nanoparticle synthesis. The UV-VIS results showed a shift in the absorption spectra of Fe-doped ZnO nanoparticles, with the maximum absorption wavelength moving from the ultraviolet (UV) region to the visible range, indicating enhanced optical properties due to iron doping. The adsorption performance of the ZnO and Fe-doped ZnO nanoparticles was evaluated under various conditions. The optimum removal efficiency for ZnO nanoparticles was achieved at pH 9, with an adsorbent dose of 20 mg, a contact time of 45 minutes, and an initial dye concentration of 5 mg/L, resulting in a dye removal efficiency of 95.23%. For Fe-doped ZnO nanoparticles, the same conditions led to a higher removal efficiency of 99.52%. The adsorption kinetics followed the pseudo-second-order model, suggesting chemisorption as the primary mechanism of dye removal. Furthermore, the study demonstrated the recyclability of the synthesized nanocomposites, showing that they could be effectively used for more than five cycles without significant loss in efficiency. These findings suggest that the green-synthesized ZnO and Fe-doped ZnO nanoparticles are promising, eco-friendly adsorbent materials for wastewater treatment, particularly for removing hazardous dyes like methylene blue, and could be applied in sustainable, cyclic water purification processes.
THE IMPACT OF PRACTICAL LEARNING ON STUDENTS ACHIEVEMENT IN CHEMISTRY. THE CASE OF ADELE SECONDARY SCHOOL
(Wolkite University, 2025-09-01) MULUGETA GOSSAYE TEKA
The purpose of this study was to investigate the impact of practical work in enhancing students’ achievements in chemistry in Adele secondary school particularly in grade 10, Sodo Woreda East Gurage zone, Centeral Ethiopia. To achieve this objective i.e. to examine impact of practical learning on students’ performance in chemistry, and on the students attitude toward chemistry; this study was employed quasi-experimental design. among a total of six targets secondary school in Sodo Woreda Adele secondary school was selected purposively. 80 students as a sample size out of 600 total populations were selected by using random sampling method. To keep the proportional allocation of students from each section, stratified sampling technique was used. The sampled students were placed in to two groups; experimental group and control group. Both the groups were exposed to the pre-test. The experimental groups were taught using the practical approach for eight week while the control groups were taught using the conventional method. The study used three instruments namely chemistry achievement tests, students’ attitude questionnaires and observation checklists were used as a data collection tools. at the beginning of the first week, both groups give the pre-test chemistry achievements and the post-test achievements test at the end of the eight week. The data obtained were analyzed using SPSS version 20. T-test was used to test the statistical significance in the hypothesis generated in the study. The significance of the results was tested at α = .05 significance level. The findings othe students showed that practical approach resulted in higher students’ achievements in chemistry and lead to improved students’ attitude towards chemistry. The study concluded that, practical instructional approach towards chemistry is an effective teaching method which chemistry teachers should be encouraged to use to enhance students’ achievements in the subject. The study recommended adoption of the practical teaching approach in order to enhance students’ achievements and improve students’ attitude towards the subject.