Chemistry
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- ItemTHERMALLY BONDED COMPOSITE FORM PALM TREE WASTES: PRPEARTION AND APPLICATION IN WASTEWATER PURIFICATION FROM TOXIC METALS(An-Najah National University, 2024-06-10) Issa, SarahWater is crucial for life on earth planet. Excessive inorganic and organic chemicals used in varies sectors such as agriculture, industry, household or other, can make the situation worse regarding pollutants in wastewater. Pharmaceuticals, paints, household chemicals, microorganisms, personal care products, plumbing chemicals, and other waste contaminants are common in sewage water. Heavy metal ions are among the most hurtful of these pollutants since they are nonbiodegradable and show long lasting effects, in addition to the high toxicity metals have even at ppm concentration. As a result, removing these hazardous heavy metal ions from water is becoming essential. The main goal of this work is to develop a process for converting palm tree waste to value added material with ionic functional groups and use for removing toxic chemicals from wastewater. Palm waste collected from Jerico areal in Palestine was ground, purified form soluble materials by Soxhelt extraction. The main three components of the waste are cellulose, lignin and hemicelluloses. All the three macromolecules have hydroxyl groups on their repeat units. The macromolecules were reacted as a mixture with sodium chloroacetate in an alkaline medium. The reaction introduced a carboxyl pendant on the three macromolecules. To reduce the extractives, the carboxymethylated polymers were thermally fused by heating them in an oven at 160 oC. The produced crosslinked composite was then used in wastewater purification form metal ions. The Thermally cured composite was characterized using FT-IR and Scanning electronic microscopy (SEM). The FT-IR results indicate the formation of the target composite, and the SEM showed a porous structure with hollow fiber. The composite was used for removing toxic metal ions for contaminated water. The effect of various parameters such as initial metal ion concentration, pH, temperature, adsorbent dosage and contact time were studied as parameters affecting the adsorption of metal ions by the target polymer. Co(II) was used as a model ion, the highest metal ions removal was obtained at pH of 8 with a Co(II) concentration of 40 ppm, adsorbent dosage of 40 mg, and contact time of 30 min. The optimum extraction temperature was determined to be about 25◦C. The adsorption process follows second-order adsorption kinetics model and thermodynamic study showed that the adsorption process is spontaneous and exothermic since as the temperature increases the absorption efficiency dropped. Waste from palm tree was successfully converted to a composite with ionic functional group and used in removal of toxic metal ions from wastewater. The composite showed excellent efficiency toward all metal ions present in a real sample of wastewater.
- ItemCELLULOSE WITH URETHANE CROSS-LINKS DECORATED WITH IONIC FUNCTIONAL GROUP FOR WASTE WATER PURIFICATION FROM TOXIC METAL IONS(An-Najah National University, 2024-04-25) Khaseeb, ShorouqBackground: water is elixir of life. Excessive chemical use in varies sectors, whether in industry, agriculture or other, can result in an increased load of pollutants in water. Radionuclides, household chemicals, pharmaceuticals and personal care products (PPCPs), microorganisms, plumbing inorganic chemicals, and other contaminants are common in water. Heavy metals are among the most harmful of these pollutants owing to their lasting effects, and toxicity even at low concentration. As a result, removing these hazardous heavy metal ions from water is becoming crucial. Objectives: The purpose of this thesis is to establish novel adsorbent material based on polyurethane foam (PUF) that was enhanced with an ionic functional group capable of efficiently absorbing harmful metals from water. Methodology: The process of creating the target polymers included a series of chemical reactions between carboxymethyl cellulose (CMC) and diisocyanate compounds (hexamethylene diisocyanate & phenylene diisocyanate) in the presence of diisopropyl amine as a catalyst, resulting in the formation of the foam polymeric materials carboxymethyl cellulose hexamethylene polyurethane foam (CMC-HMPUF) and carboxymethyl cellulose phenylene diisocyanate polyurethane foam (CMC-PPUF) with urethane links. Results: The adsorption capacity of polymeric foams toward Pb(II) was assessed using a variety of parameters such as temperature, pH, adsorbent dose, time and initial ion concentration. In addition, the optimal value of each of the parameters that resulted in quantitative elimination of Pb(II) were discovered. The percentage removal of Pb(II) by CMC-HMPUF polymer was around 95%, while CMC-PPUF was approximately 93%. Adsorption thermodynamics, kinetics, and isotherms were also studied to gain insight into the mechanism and spontaneity of adsorption. The result demonstrate that the adsorption of Pb(II) process is classified exothermic process (∆H°<0), and spontaneous at low temperatures (∆G°<0),( ∆S°<0). The obtained isothermal and kinetic values illustrated that the adsorption by the two foams fit the Freundlich model, and obey a Pseudo-second order kinetic. The created foams exhibited a great propensity to remove multi-metal ions found in an actual sample of sewage water. Conclusion: The goal polymers were made, and urethane linkages were detected using IR spectroscopy, the two polymers foam showed strong thermal stability, they were effective in removing heavy metals from wastewater.
- ItemPREPARATION OF COPPER NANOPARTICLES ONTO COPPER SHEETS AND ELECTROCATALYTIC APPLICATION IN WATER DE-NITRATION(An-Najah National University, 2024-04-01) Hijazi, SamaaThe issue of water contamination, specifically with nitrate ions, is a growing concern on global and Palestinian levels. This pertains to both groundwater and surface water sources. The escalation in nitrate pollution can be attributed to the excessive and improper utilization of chemicals as a consequence of human activities. The utilization of electrochemical reduction of nitrate presents a viable method for addressing this issue. The key goal of this study is to enhance the removal of nitrate by highly selective electroreduction to N2. The aforementioned objective is accomplished through the alteration of an inexpensive, reliable, and durable electrode that exhibits exceptional efficiency in nitrate reduction. The bench-scale undivided electrochemical cell was utilized in the potentiostatic mode, aiming to obtain reduced power consumption. The experimental setup consisted of three distinct electrodes: a reference electrode known as the saturated calomel electrode (SCE), a counter electrode in the form of a platinum (Pt) sheet, and one of the newly modified electrodes served as the working electrode. Customized electrodes comprise Cu@Cu modified by electrodeposition of Cu nanoparticles on a chemically pure Cu sheet, FeCl3 chemically etched copper electrodes, and copper sheets modified by graphene. The graphene modification was eliminated due to several reasons that will be discussed later. The electrodes underwent characterization through the utilization of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). Among the studied electrodes, the copper nanoparticle electrodeposited electrode (Cu@Cu-1) results displayed the most significant nitrate conversion rate, reaching 92.3% and 85.05% selectivity towards N2 gas within a time frame of 420 minutes. Furthermore, the kinetics associated with the electrochemical reduction of nitrate via the Cu@Cu-1 electrode was examined through the use of the initial rate method. The investigation revealed a reaction rate order of 0.85. Additionally, the rate constant was determined by analyzing the intercept of the plot that is equal to ln k, from which k was found to = 1.39 × 〖10〗^(-2) min-1.
- ItemTHERMO-OXIDATIVE DECOMPOSITION ANALYSIS OF LEVOFLOXACIN BY ISOCONVERSIONAL KINETICS AND COMPUTATIONAL METHODS(An-Najah National University, 2024-03-11) Thaher, Mohammed Nash’atThis study presents a thorough thermogravimetric analysis (TGA) to comprehend the thermal decompaction of the antibiotic drug levofloxacin, as a model pharmaceutical pollutant. The reaction was analyzed under N2 gas flow using a TGA analyzer at different heating rates. The isoconversional methods of Kissinger–Akahira–Sunose (KAS) and Friedman were applied to obtain the effective activation energy (Eα) of the decomposition as a function of the extent of conversion (α). The Eα of levofloxacin’s decomposition reaction was found to be between 23.3 – 68.5 kJ/mol for the KAS method, and between 48.3 – 117.5 kJ/mol for the Friedman method, positively correlating to α. Additionally, Differential scanning calorimetry (DSC) was used to assess the thermodynamic physical and chemical changes that occur as a function of temperature. And Density functional theory (DFT) calculations were used to calculate the bond dissociation energies (BDEs) of the levofloxacin possible degradation routes. The DFT analysis along with DSC and Friedman method’s results suggest that the most probable dissociation route is aromatic-Me bond to give off •CH3 radicals.
- ItemVARIATIONS OF THE CHEMICAL CONSTITUENTS AND PHARMACOLOGICAL ACTIVITIES OF ARTEMISIA, CHILIADENUS IPHIONOIDES, TEUCRIUM POLIUM. ESSENTIAL OILS FROM JERICHO-PALESTINE(An-Najah National University, 2025-03-08) Saed, EmanThe growing fascination with medicinal plants is primarily due to the perception that certain plants can treat various conditions without causing negative side effects. In our region, three common herbs, Artemisia, Chiliadenus iphionoides, and Teucrium polium, have been employed in several traditional treatments for a considerable duration. This study aims to examine the chemical compositions of the essential oils (EO) from Artemisia, C. iphionoides, and T.polium gathered in Jericho, as well as their antioxidant, antibacterial, antilipase, and anti-amylase properties. Essential oils were extracted from Artemisia, C. phionoides, and T.polium using hydrodistillation, with their chemical contents characterized subjectively and quantitatively via GC-MS analysis. The antioxidant efficacy of the essential oils was evaluated by inhibiting 1, 1-Diphenyl-2-picrylhydrazyl (DPPH) free radicals. The micro-dilution technique was employed to assess antibacterial efficacy. The anti-lipase activity was assessed utilizing p-nitrophenyl butyrate (PNPB). The activity of anti-amylase was evaluated utilizing 3,5-dinitrosalicylic acid (DNSA). Seventeen chemicals were found in T. Polium, of which E-nerolidol (27.11%), geranyl acetone (23.26%), germacrene D (19.08%), β-caryophyllene (17.78%), α-caryophyllene (3.35%), and bicyclo germacrene (3.08%) as the major constituents. In C.iphionoides, 47 chemicals were found, comprising 98.81% of the total oil, with cresol methyl ether (52.93%), ethyl oct-2-note (14.36%), epi-cadinol (6.56%), 1,8-cineole (4.25%), and epi-α-eudesmol (3.66%) being the major constituents. Fifty-one chemicals were discovered in Artemisia, with 1,8-cineole (28.67%) as the predominant component, followed by trans-thujone (24.0%), cis-thujone (17.69%), camphor (12.76%), and terpinen-4-ol (8.34%). The essential oils of T. Polium, C. iphionoides, and Artemisia leaves exhibited notable antioxidant activity, with IC50 values of 19.18± 0.34 µg/mL, 17.03± 0.59 µg/mL, and 35.00± 0.47 µg/mL, respectively. The 1:1 mixtures of Artemisia essential oil (EO) with C. iphionoides EO, Artemisia EO with T. Polium EO, and C.iphionoides EO with T. Polium EO showed comparable antioxidant activity, with IC50 values of 17.13 ± 0.70 µg/mL, 28.96 ± 0.16 µg/mL, and 18.47 ± 0.86 µg/mL, respectively, all of which are less effective than Trolox (IC50 = 4.3 ± 0.58 µg/mL).Artemisia essential oil and C. iphionoides EO exhibited moderate antibacterial activity, with MIC values of 3.906 and 31.3 µL/mL and MBC values of 250.0 µL/mL. T.Polium had negligible antibacterial activity. The extracted essential oil demonstrated inhibitory effects on swine pancreatic lipase, with IC50 values of 534±0.19 µg/mL for Artemisia, 368.13±0.62 µg/mL for T.polium, and 931.58±0.91 µg/mL for C. iphionoides. The isolated essential oil demonstrated α-amylase inhibitory action with IC50 values of 569 ± 0.20 for Artemisia, 569 ± 0.20 µg/mL for T. Polium and 1550 ± 0.25 µg/mL for C. iphionoides.