Chemical Engineering
Permanent URI for this collection
Browse
Recent Submissions
- ItemWhey as a Resource: Transforming Dairy Waste into Lactic Acid(2025-07-10) Ameer Abu Hayat; Deema Tammam; Nadeen Hawash; Omar AlabedABSTRACT Lactic acid production from whey presents an attractive opportunity to reduce environmental waste and promote sustainable bioprocessing. This project addresses the worldwide issue of underutilized dairy by-products by turning them into compounds with added value that can be used in food additives, pharmaceuticals, and biodegradable plastics. Its importance resides in advancing the circular economy by converting industrial waste into products that are both economically viable and environmentally advantageous. The main objectives of this study were to isolate and identify lactic acid bacteria (LAB) from dairy sources (labneh, cheese whey, and yogurt). In addition, to generate a growth rate curve, and to evaluate lactic acid yield using both pure LAB strain and mixed microbial cultures across various substrates. Key aspects of the study include analytical validation and microbial strain isolation. The assessment of fermentation parameters, including pH, nutrient supplementation, the choice of carbon and nitrogen sources, and the contribution of native proteins to the enhancement of lactic acid production, was given particular attention. An economic feasibility study was also incorporated into the project to evaluate the possibility of practical implementation. In this context, LAB were successfully isolated from labneh, cheese whey, and yogurt using De Man Rogosa and Sharpe (MRS) agar and confirmed through Gram staining and biochemical testing. Growth dynamics were monitored via optical density (600 nm). Lactic acid was produced by pure strains of LAB and mixed cultures through fermentation at 37°C, and lactic acid was quantified through UV spectrophotometry and titrimetric analysis. It was found that, yogurt is a more efficient source of Lactobacillus strain. In mixed culture fermentation, a maximum lactic acid yield of 35 g/L was achieved when pH adjustment to near-neutral levels and nutrient supplementation were used. Whereas lactose led to decreased productivity, native proteins in cheese whey increased microbial activity. Labneh whey was verified as the most stable and effective substrate in pure strain fermentation. Glucose and lactic acid calibration curves confirmed analytical reliability, and economic analysis projected a net profit of 199,150 ILS/year, supporting the industrial scalability and sustainability of whey valorization.
- ItemSynthesis of Ag-ZnO Hybrid for photocurrent production(2025-02-27) Heba ZaidAbstract Photovoltaic solar technologies offer a promising solution to the global energy crisis and the increasing demand for clean energy sources. Studies suggest that zinc oxide (ZnO) and silver nanoparticles (Ag-NPs) can enhance the properties of dye-sensitized solar cells (DSSCs) due to their abilities in electron transport and light absorption. This study aims to synthesize and characterize a ZnO-Ag hybrid structure to improve photocurrent production. This study focuses on the synthesis and characterization of silver nanoparticles (Ag-NPs), zinc oxide nanoparticles (ZnO-NPs), and their hybrid structure (ZnO-Ag) for enhanced photocurrent production. Ag-NPs were synthesized using a polyvinylpyrrolidone (PVP) and ethylene glycol system, while ZnO-NPs were prepared via a microwave-assisted method followed by calcination. The hybrid structure was formed by combining Ag-NPs with ZnO-NPs under controlled conditions. UV-Visible spectroscopy confirmed the successful synthesis, with Ag-NPs exhibiting a peak at 461 nm and ZnO-NPs showing a peak at 370 nm, reflecting their optical and semiconducting properties. The fabricated samples were tested using a potentiostat to evaluate their photocurrent performance. I-V curve analysis revealed a significant improvement in short-circuit current (Isc) and open-circuit voltage (Voc) for the hybrid structure (Isc = 3.34 A, Voc = 2.23 V) compared to single-layer samples of ZnO or ZnO-Ag. This enhancement, reaching up to 50%, is attributed to improved charge transport, plasmonic effects of silver nanoparticles, increased surface area, and reduced charge loss within the hybrid structure. These results demonstrate the superior performance of the ZnO-Ag hybrid, showcasing its potential in photovoltaic and optoelectronic applications. The findings pave the way for future research to further optimize hybrid nanostructures for energy conversion technologies.
- ItemOlive Solid Waste As An Alternative of Coconut Charcoal(2025-01-19) Noor Rehan.; Sabreen Quzmar; Ruba Arafat; Bara’a BsharatProject’s Abstract: Charcoal is produced by extracting water and other volatile components from animal and plant materials without oxygen. Since ancient times, charcoal has been used for various purposes, including art, medicine, and fuel. This experimental study aims to make charcoal from solid olive waste (peat) with properties based on international standards. It also includes the steps of manufacturing the charcoal to be produced in this study, which begin with drying the raw materials and carbonizing them by pyrolysis, followed by grinding and screening, then mixing the produced powder with starch and shaping it into briquettes, followed by pressing and drying and determining the physical and chemical properties of the produced charcoal. The first step in preparing charcoal was to purify the raw material (peat) from impurities and residual oil by washing it several times with hot water. It was dried in an oven for 24 hours and then cooled to room temperature. Carbonization (pyrolysis) was carried out by placing a dried and weighed peat sample in an oven at 500 °C for 2 hours. After carbonization was completed, the samples were cooled to room temperature inside a dryer. 100 grams of charred peat was ground using an electric grinder until it turned into a fine powder, then it was mixed with 30 ml of water and different concentrations of starch (1%, 2%, and 5%) until it became a homogeneous mixture. The experimental results showed that the high percentage of starch caused an increase in the percentage of ash resulting from the charcoal produced when used, and through this study, the percentage of starch 1% was adopted as the best sample for international standards for charcoal, after relying on the standards followed in Indonesia, the United States, and Japan, and the following results were obtained: moisture content 5%, volatile matter content 9%, ash content 6%, fixed carbon 80.5%, and calorific value 6233 (kcal). In addition, it was found that increasing the drying time after preparing the charcoal briquettes (about 48 hours) increases the hardness and ignition of the charcoal. The analytical study conducted on 10 people using the produced charcoal showed that the quality was very good and similar to the coconut charcoal available in the market, in terms of smell, ignition, and ash content produced with slightly less hardness due to the use of simple pressing tools
- ItemTurning Waste into Wealth: Bioethanol Synthesis from Food(2024-12-10) Omnia Atatrah; Ruaa Al-QasarwaAbstract This research explored the production of bioethanol from food waste, with a focus on dates as a sustainable feedstock. Bioethanol, a renewable energy source, presents a viable alternative to fossil fuels due to its lower greenhouse gas emissions and biodegradability. The project aimed to explore ethanol production by investigating various fermentation processes using glucose and date substrates. Dates were pretreated, and the fermentation process was monitored by measuring sugar consumption and ethanol yield through distillation. The fermentation of dates and glucose were carried out at 30 °C using instant dry commercially available baker’s yeast (Saccharomyces cerevisiae). The results indicated that glucose fermentation was completed within 6 hours, while dates required slightly longer due to the complexity of their sugars. Despite the slower rate, dates produced approximately 91.3% of the ethanol yield achieved with glucose. Furthermore, increasing the substrate concentration from 100 g/L to 200 g/L significantly enhanced ethanol yield, increasing from 15.01% to 34.54%, demonstrating the impact of substrate concentration on ethanol production. pH monitoring revealed a steady acidification during fermentation, essential for efficient ethanol conversion. The study demonstrated the potential of dates as an effective feedstock for bioethanol production. Future research could focus on optimizing fermentation through the use of different yeast strains, enzymatic treatments, and scaling the process for industrial applications, contributing to the advancement of sustainable biofuel production.
- ItemProduction and Characterization of Nanocomposites Composed of Polyvinyl Alcohol and Silver(2024-09-22) Abeer Bsharat; Shahed Salameh; Sondos sobohAbstract Nanocomposites are synthetic or naturally occurring solid materials created by combining two or more different constituent materials, each with its own important physical or chemical qualities, to form a new substance with enhanced properties. PVA/Ag nanocomposites are currently in great demand for a variety of industrial applications due to their improved thermal, optical, electrical, and antibacterial properties. In this work, Ag-NPs have been synthesized by using rapid method (microwave-assisted method), studying the effect of the microwave power on Ag-NPs properties like optical such as energy bandgap, electrical, product yield and then used to enhance the properties of PVA films such as electrical, thermal, and antibacterial properties. It was found that the power affected size, increasing power leads to an increase in size and a decrease in the energy band gap from 2.93eV to 2.55eV. As for the product yield, 22.11% of the Ag-NPs which is not significantly change d by power changes, The synthesized Ag-NPs showed a broad spectrum of antibacterial activities toward different Gram-positive and Gram-negative bacteria strains, The decrease in power lead to a decrease in the Ag-NPs’ size , inducing an increase in their ability to penetrate the cell membrane, improving antibacterial activity for Ag-NPs. Ag/PVA nanocomposite film caused high colony forming unit reduction from 36 to 6 with a reduction percent of 84 %for the E. coli bacteria. Different volume of Ag-NPs that were prepared at medium- low power and combined with PVA polymer to give Ag/PVA nanocomposite film. The UV-Vis absorption of Ag/PVA nanocomposite film increases with increasing Ag-NPs had with a slight effect on the band gap, resulted from the distribution of the particles within the PVA film. Also, the electrical conductivity of PVA film increases from 0.065 S/m to 0.57 S/m with increasing the amount of Ag-NPs added to the film, the degree of crystallinity of PVA film increases from 14.047% to 18.331% with increasing the wt% of Ag-NPs added to the film.