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Bulletin of the Chemists and Technologists of Bosnia and Herzegovina
Issue 46
Publication date: June 2016 |
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Table of contents
Biogas from Poultry Manure Original Scientific Article
Berbić Medina, Avdić Nurudin
Abstract: It is estimated that around 2 billion of waste annually is formed in the European Union (EU), which is deposited-in sanitary and industrial dumps, and it is recorded continuous increasing in the production of organic waste. Biodegradability of organic substances enables the emission of CH4 (biomethane) that has 25 times higher the greenhouse potential than CO2 as a predominant greenhouse gas in the atmosphere. The treatment of organic waste through anaerobic digestion flourished in the 20th century, thus opening the way to the environmental remediation of manure, as one of the most influential source of methane emissions. This study research the production of methane in poultry manure, as one of the most usual animal fertilizers in Bosnia and Herzegovina. The research activities are comprised of waste characterization and testing the biodegradability of waste using Biomethan Potential Test BMP The temperature range of the study was 37 ± 1°C (mesophilic process). The research topic is manure of laying hens, without bed. The conducted research activities have shown the existence of possibilities for the production of biogas by using anaerobic biological treatment of poultry manure. The yield of biogas in the amount of 5752 mL was achieved with a methane content of 53.19% for the treatment of the substrate with 15% total solid (TS). By treating the substrate with 17% total solid (TS) less biogas is obtained, in the amount of 2337.50 mL of biogas but with a higher content of methane, in the amount of 56.36%. Physico-chemical analysis revealed a deviation ratio of C(COD):N:P:S from the optimal ratio for substrate and digestate, which caused disturbances in the performance of the anaerobic digestion process. Inadequate ratio is expressed with low carbon content and a high content of nitrogen and sulfur. The course of the study has proven to be extremely useful for testing the possibilities of biogas production in combination with other organic waste, which opens up opportunities for further research.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 46, 1-6.
Investigation of the influence of magnesium chloride to sulfate corrosion of concrete Original Scientific Paper
Bikić Farzet, Brkić Dejana
Abstract: The paper research subject is to examine whether chlorides of magnesium chloride block the affect of sulphate of magnesium sulfate to the concrete, that is, whether they block the sulfate corrosion of concrete. The cylindrical samples of cement paste measuring 80 × 40 mm of varying water-cement ratio 0.5 and 0.7 (kg H2O / kg of cement) were prepared for implementation of planned research. The samples were immersed and treated for nine months in following solutions: 1% MgCl2, 1% MgSO4, 1% MgCl2 + 1% MgSO4, 5% MgCl2, 5% MgSO4, 5% MgCl2 + 5% MgSO4. In order to study concrete corrosion, the samples were dried, grounded and analyzed by X-ray diffraction analysis (XRD), after being removed from the solutions. Treated cement paste samples in solutions of MgSO4, the concentration of 1% MgSO4 and 5% MgSO4, at both water-cement ratios form ettringite formula 3CaO×Al2O3×3CaSO4×31H2O.Ettringite occurs in reactions of sulfate and aluminate hydrate and could lead concrete structure to a state of destruction. The reaction is also known as sulphate corrosion of concrete. In joint solutions of magnesium salt of concentration of 1% MgCl2+ 1% MgSO4and 5% MgCl2+ 5% MgSO4, at both water-cement ratios, chlorides with aluminate hydrate form monochloroaluminate hydrate formula 3CaO×Al2O3×CaCl2×10H2O,while sulfates react with calcium hydroxide to gypsum without forming expansive ettringite on samples of the cement paste. Blocking the formation of expansive ettringite verifies the blocking of sulfate corrosion of concrete by chloride from magnesium chloride.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 46, 7-12.
Effect of Ultrasound on Biodiesel Synthesis from Plant Oil Original Scientific Paper
Nuhanović Mirza, Pehlić Ekrem, Čišija Vedad, Gutić Sanjin
Abstract: The recent studies have clearly shown that the continuous exploitation of fossil fuels has adverse effects on the environment, while reserves of oils are sufficient for about next fifty years. As the need for energy rises, so do the energy policies tend to develop and research the renewable energy sources including biodiesel. The goal of this research is to examine the ultrasound effect on biodiesel synthesis process and to optimize synthesis conditions, examining the effect of several parameters in production process and biodiesel quality. Biodiesel synthesis was processed out of unused sunflower oil and sunflower oil used in fast-food (waist oil). Particularly, the ultrasound effect on production process-transesterification reaction was examined. After synthesis, examination of density, viscosity, flash point and yield were done using suitable apparatus and methods. The study results proved that the most optimal temperature with the use of ultrasound is 60oC, sonication time of 15 minutes and alcohol-oil molar ratio 3:1. Also, the results proved that using ultrasound during biodiesel synthesis, transesterification reaction can be processed on lower temperatures and still, biodiesel of good quality can be produced, contrary to conventional synthesis. Using the ultrasound generator for laboratory biodiesel synthesis largely shortens reaction time, increases rate of chemical reaction, decreases by-product amount, decreases alcohol amount, decreases waste water and, in the end, saves energy because the reaction is faster and takes less time at lower temperatures.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 46, 13-18.
Analysis of Some Metals in Human Hair by the AAS Method Original Scientific Paper
Mutap Amira, Huremović Jasna, Nuhanović Mirza
Abstract: The essential and toxic elements are contained in drinking water, food and the air - in the entire general human surrounding. Considering the effects of these elements on human health, the recommended/allowed levels of their intake into the organism are defined by the national and international regulations. Those levels are an important indicator of the state an organism is, which is determined by different biological samples of human origin. In this work, the determination of the concentrations of metals was performed on human hair samples of the people living on the area of Kiseljak. The metal levels that were established in the hair were of those essential metals (copper, zinc, calcium, magnesium, iron) and of two toxic metals (chromium and cadmium). The human hair sampling was carried out during the period of November 2014. - February 2015. The group of responders was male and female donors of various ages, (2-66 years old). By the examination of the results, the specifications that were taken into consideration were the following: age and gender of the hair donor, chemical treatment of the hair, smoking habits of the donors. The technique that was applied for determining the concentration of the heavy metals in the samples was the atomic absorption spectrometry (AAS). The final results showed a normal and in some cases increased, concentration of essential metals. The content of Cr and Cdin all analyzed samples was below the limit of quantificationof used technique.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 46, 19-26.
DFT Structural Analysis of Chamazulene Original Scientific Paper
Salihović Mirsada, Šapčanin Aida, Špiritović-Halilović Selma, Završnik Davorka
Abstract: A combined theoretical and experimental study on the structure, infrared,UV-Vis,1H and 13C NMR data of chamazulene is presented. Theoretical geometry optimizations and some additional properties of chamazulene and their IR, UV-Vis, NMR spectra were calculated using the DFT B3LYP /6-31G(d) level. Calculations were done using software Spartan 10. Experimental data showed that chamazulene have absorption maximum at 340 nm to 530 nm. The position of max did not much differ from the theoretically calculated value. The calculated density of states showed excellent agreement with UV/Vis diffuse reflectance spectra predicting the absorption maximum at 310 nm (calculated 332 nm) to 530 nm (calculated 516 nm). The IR normal modes were assigned for the two very small sp2 CH valence bands and strong sp3 CH vibrations. The aromatic overtone vibrations can hardly be detected and also the C=C vibration is very weak.1H NMR spectroscopy, showed resonances of the ring protons between 7 and 8 ppm. The methyl groups and the methylene group appear rather deshielded at 2.7 and 2.9 ppm. The calculations yielded reliable results that were in good correlation with experimental data. This study is a good basis forcollaboration between experimentalists and quantum chemists.
Solvent-free Synthesis and Antibacterial Activity of 14-Aryl Substituted Dibenzoxanthene Derivatives Original Scientific Paper
Veljović Elma, Špirtović-Halilović Selma, Kahrović Emira, Roca Sunčica, Novaković Irena, Osmanović Amar, Salihović Mirsada, Alagić Davor, Hastor Benjamin, Ljubunčić Dženana, Završnik Davorka
Abstract: Xanthene derivatives are important compounds because of their proven biological activities. Seven 14-aryl-14H-dibenzoxanthenederivatives were synthesized by reliable solvent-free synthesis procedure using iron (III) chloride hexahydrate as a catalyst. Three synthesized derivatives possess antibacterial activities against different bacteria. Compound 14-(2’,5’-dimethoxyphenyl)-14H-dibenzo[a,j]xanthene(3) showed best activity against Escherichia coliand Staphylococcus aureus with MIC 0.616 mg/mL. Docking study for the most potent compound was carried out by taking amino terminal domain of enzyme I as a target for antibacterial activity against Escherichia coli and it was shown that binding energy of 3 was similar to amikacin’s (around –4.2 kcal/mol) used as a referent drug, although bound on a different sites on enzyme.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 46, 33-38.
Determination of Pesticide Residues in Honey usingGC-MS Technique Original Scientific Paper
Kurtagić Harun, Čopra-Janićijević Amira
Abstract: Ten samples of honey(Mountain Honey, Mountain flower honey, Flower honey and Chestnut honey) were analyses for 26 organochlorine, carbamate and orgaphosphorus pesticides residues. An analytical procedure was based on QuEChERS extraction with acetonitrile followed by gas chromatography-mass spectrometry. The calibration curves constructed were linear over the range from 0.01-0.25 mlL-1. The correlation coefficient were ≥ 0.995 for all pesticides standards. The mean recoveries for extractions were 70-125% for lower concentration range (0.02 mg/kg) and 62-135% for the higher concentration range (0.10 mg/kg) for pesticides analysed. Six different pesticides, propham and carbofuran (carbamate pesticides), methyl parathion, dichlorvos sulfotep and malathion (organophosphate pesticides) were detected in the analysed honeys samples.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 46, 39-42.
Determination of the Daily Rhythm of Cortisol in the Saliva of Women and Men Original Scientific Paper
Ljubijankić Nevzeta, Kučukalić Elma, Ljubijankić Sead
Abstract: Saliva provides a useful and noninvasive alternative to blood for many biomedical diagnostic assays. Recently, saliva has been used as a biological sample of choice for the monitoring of hormones and other clinically important biomolecules. The assessment of cortisol in saliva has proven to be a valid and reliable reflection of the respective unbound hormone in blood and is widely accepted and a frequently employed method. Due to several advantages over blood cortisol analysis (e.g., stress-free sampling, laboratory independence, lower costs) saliva cortisol assessment can be the method of choice in basic research and clinical environments. Synthesis and secretion of cortisol has the most obvious circadian rhythm in nature. The highest concentration of cortisol in extracellular fluids is in the morning hours and the lowest one in the evening. The object of this study was to determine and compare the daily fluctuations of cortisol in saliva by measuring cortisol levels in the saliva of healthy individuals daily in certain periods. Next step was to compare the values of the concentrations of cortisol in test subjects of different sexes and determine the benefits of analysis of cortisol in saliva.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 46, 43-46.
Rosemary as ecologically acceptable corrosion inhibitor of steel Original Scientific Paper
Ćatić Sead, Obralić Ema, Bratovčić Amra
Abstract: In recent years, due to increasing interest and attention of the world towards environmental protection, there has been a complete reduction or use of a certain number of corrosion inhibitors. Corrosion inhibitors are substances which, added in small quantities in aggressive media, may greatly reduce the rate of corrosion of metals. In the development of corrosion inhibitors, it is necessary to pay special attention to their toxicity and impact on environmental pollution. The research of plant extracts have become a great area of interest in the study of corrosion inhibitors. Testing the ability to protect steel was performed with plant material (Rosmarinus officinalis L.). In order to determine the basic parameters that show the effectiveness of green inhibitors, electrochemical measurements of corrosion rate were carried out. Results obtained by DC techniques (method of Tafel extrapolation) showed that the corrosion rate decreases in the presence of the tested corrosion inhibitor. Studies have shown that, in a certain concentration, rosemary (Rosmarinus officinalis L.) has the effectiveness of the protection of steel in 3% NaCl, and as such, it is considered an acceptable corrosion inhibitor.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 46, 47-50.
The effect of chlorogenic acid on the Briggs-Rauscher oscillating reaction Original Scientific Paper
Dacić Minela, Gojak-Salimović Sabina
Abstract: The Briggs-Rauscher oscillating reaction can be used as test for antioxidant activity of pure compounds or food extracts. Antioxidants are substances that have the ability to neutralize free radicals, which are harmful to human health. Adding the substances with antioxidant ability to the reaction mixture, oscillations temporarily stops, and after a certain time the oscillating reaction starts again. The period without oscillations is known as inhibition time, and it's proportional to the quantity of antioxidant species in reactive mixture. In this study the Briggs-Rauscher reaction was used to measure the antioxidant activity of chlorogenic acid. Inhibition time, duration of reaction and the number of oscillations was determined varying the concentration of chlorogenic acid and solvent (water, ethanol, dimethyl sulfoxide). Flow of oscillations in the Briggs-Rauscher reaction mixture was monitored as a change in potential between the platinum and silver-silver chloride electrodes at room temperature. With increasing concentrations of chlorogenic acid in all three solvents the inhibition time of oscillations is increased.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 46, 51-54.
