The objective of this study is to extract phenolic compounds from nettle and melissa by using microwave and ultrasound and to compare these methods with conventional extraction and maceration, respectively. Extraction of melissa essential oil was also studied. In extraction of phenolics, effects of extraction time (5-20 min for microwave / 5-30 min for ultrasound) and solid to solvent ratio (1:10, 1:20, 1:30 g/ml) on total phenolic content (TPC) were investigated for microwave and ultrasound extractions. Different powers were also studied for ultrasound extraction. In addition, effect of solvent type (water, ethanol, ethanol-water mixture at 50:50 v/v) was analyzed and water was found as better solvent. Optimum conditions for microwave extraction of phenolics were determined as 10 min and 1:30 solid to solvent ratio for nettle, and as 5 min and 1:30 solid to solvent ratio for melissa. TPC at these conditions for nettle and melissa extracts were 24.6 and 145.8 mg GAE/g dry material, respectively. Optimum conditions for ultrasound extraction was 30 min, 1:30 solid to solvent ratio, and 80% power for nettle and 20 min, 1:30 solid to solvent ratio, and 50% power for melissa. TPC at these conditions for nettle and melissa were 23.9 and 105.5 mg GAE/g dry material, respectively. Major phenolic acids were determined as naringenin in nettle and rosmarinic acid in melissa. Major aromatic compounds in melissa essential oil were found as limonene, citral, and caryophyllene oxide. Yields of essential oil obtained by microwave and hydrodistillation were 4.1 and 1.8 mg oil/g dry sample, respectively.

ABSTRACT COMPARISON OF SORPTION CAPACITIES OF HYDROCARBONS ON DIFFERENT SAMPLES OF MCM-41 AYDOGDU, Birsu M. Sc., Department of Chemical Engineering Supervisor: Prof. Dr. Hayrettin Y&Uuml / CEL Co-Supervisor: Prof. Dr. G&uuml / rkan KARAKAS January 2013, 69 pages MCM-41(Mobil Composition Matter-41) is one of the three members of M41S family and has a highly ordered hexagonal honeycomb like structure with a narrow pore size distribution in mesopore range, high surface area, high pore volume and high thermal stability. These features make MCM-41 proper to use for adsorption, catalysis, ion exchange and separation processes. . In this study sorption capacities of C8 aromatics (o-, m-, p-xylene and ethylbenzene at 30 &deg / C, 50 &deg / C and 65 &deg / C) on a MCM-41 sample synthesized in our laboratory were determined gravimetrically by using a commercial automated electro balance system and compared with results obtained in a previous and similar MSc thesis study with a sample of different origin and characteristics / specifically low BET surface area (492 m2/g). MCM-41 sample was synthesized by hydrothermal synthesis method with cetyltrimethylammoniumbromide (CTAMBr as surfactant) and tetraethyl ortosilicate (TEOS as silica source) in basic conditions. This MCM-41 sample was calcined at 540 oC for 8 h and characterized by XRD, nitrogen adsorption at 77 K, TGA, TEM, SEM and SEM-EDX. According to XRD data, main characteristic peak for synthesized MCM-41 was obtained at 2&theta / =2.28&deg / . Three small reflection peaks can be seen at 2&theta / values of 2.59, 4.27&deg / and 4.5&deg / . XRD pattern of the MCM-41, indicated that the desired structure of MCM-41 was successfully synthesized. Surface area, pore volume and average pore diameter were obtained from the nitrogen adsorption data at 77 K as 1154 m2/g, 1.306 cm3/g and 2.75 nm respectively. TGA analysis showed that the 540 oC is proper for the calcination. SEM -EDX analysis gave an oxygen atomic concentration 66.40% and silicon atomic concentration 33.60%. These results showed that the chemical composition of the synthesize material was in almost pure SiO2 form. The adsorbed amount for all isomers at the same pressure decreased as the temperature of the adsorption isotherms increases as expected for physical adsorption. Nitrogen adsorption of MCM-41 in this study showed type IV isotherm with H2 type hysteresis loop according the IUPAC classification. However, for o-,m-, and p-xylene an approximately linear increase in the adsorbed amount as a function of relative pressure was observed from the adsorption isotherms. Except for adsorption isotherms of m-xylene and p-xylene at 65 oC all isotherms of xylenes showed hysteresis loops. Hysteresis loops narrowed down with increasing temperature. p-xylene and m-xylene adsorption isotherms at 65 oC were reversible and did not show any hysteresis loop. Ethylbenzene adsorption isotherms at 30 oC, 50 &deg / C and 65 oC also showed a linear increase in the adsorption amount as a function of relative pressure like xylenes. At 50 &deg / C and 65 oC adsorption isotherms of ethylbenzene were reversible without a hysteresis loop. For all adsorbates volume of adsorbed amounts were calculated on the assumption that they exist as saturated liquids at the isotherm temperature and found to be significantly lower than pore volume obtained from nitrogen adsorption isotherm at 77K. Sorption capacities of these hydrocarbons on MCM-41 were also very low when compared to values found in a previous study which involved a MCM-41 sample of significantly lower surface area ( 492 m2/g ). This may be attributed to structure degradation which requires further investigation.

Although the chemistry of benzenoid and nonbenzenoid quinones have been the subject of extensive theoretical and experimental studies, the extent of our present understanding regarding the geometries and stabilities of quinones of pentalene is meager. After studying the existence of cyclopentadienone and its reactivity as a diene and dienophile in the literature, the study of some related species, particularly the ones with fully unsaturated pentalenic structures were started. In this thesis, the elusive compound bicyclo[3.3.0]octa-3,5,8-triene-2,7-dione was tried to synthesize by using the synthetic strategy which was developed by us. We used cycloheptatriene as the starting material. The bicyclic endoperoxiedes mixture obtained by the photooxygenation of cycloheptatriene was v treated with triethylamine to give tropone in high yield. Selective reduction of tropone afforded cyclohepta-3,5-dione which was converted by the way of photochemistry to the bicyclo[3.2.0]hept-6-en-3-one. After protection of the carbonyl group, dibromocarbene was added to the double bond to give desired bicyclic compound with pentalene skeleton. Substitution of the allylic bromide with hydroxyl group followed by PCC oxidation resulted in the formation of a diketone. All efforts to convert this diketone into fully conjugated system failed.

In the last few decades, numerous studies have been conducted on xenobiotic compounds due to their vast use in industries, households, etc. and consequently high exposure of these compounds. The main focus of this study is nonylphenol compounds such as nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), nonylphenoxy acetic acid (NP1EC) and nonylphenol (NP), which are among the harmful xenobiotic compounds that can cause endocrine disruption, cancer and other health problems and which are used widely in the production of surfactants and personal care products. In this study, laboratory scale aerobic semi continuous reactors containing Waste Activated Sludge (WAS) spiked with NP2EO were operated for a period of 91 days, to inspect the decomposition of NP2EO in solid and liquid phases. The results obtained on the final day of operation (91st day) showed that NP2EO degraded into product compounds among which NP1EC contributed to 90% of molar mass. In general, NP2EO showed a sharp degradation while NP1EC was produced rapidly. NP1EO also showed a steady degradation. However, NP was accumulated in the reactor. During the study, TS, VS, TSS and VSS degradation was also monitored and the percentage removals were found to be between 40-60%. COD removal on the other hand was between 64-66%.

Cotton stalk lignin extractions were performed via alkaline methods at different conditions. Crude and post treated cotton stalk lignins, olive mill wastewater and garlic stalk juice were examined in terms of antimicrobial activity. Antimicrobial lignin was isolated depending on alkaline extraction conditions. Lignin extracted at 60&deg / C exhibited significant antimicrobial effect towards both Escherichia coli and Bacillus pumilus. However different post treatments such as ultrasonication and TiO2-assisted photocatalytic oxidation did not result in antimicrobial compounds. Olive mill wastewater and garlic stalk juice exerted substantial antimicrobial effects towards tested microorganisms. Xylan-based biodegradable films containing lignin, garlic stalk juice, tannic acid and olive mill wastewater were characterized against both B. pumilus and E. coli by means of their antimicrobial activities. E. coli exhibited lesser sensitivity to all tested antimicrobial xylan films except tannic acid-integrated xylan film than B. pumilus. Antimicrobial lignin integrated-xylan film exhibited stronger effect towards tested microorganisms than tannic acid-integrated film. In the case of both antimicrobial lignin and tannic acid integrated xylan films, 4% was found to be the maximum antimicrobial compound percentage in film forming solutions to observe continuous film formation. Lignin samples with/without antimicrobial activity were characterized by means of their chemical structure via FTIR and LC-MS. FTIR results revealed that cotton stalk lignins were significantly broken down via alkaline treatment and this breakdown resulted in the formation of new fractions and also ester &amp / ether bonds between antimicrobial hydroxycinnamic acids and lignin were cleaved during the alkaline treatments of cotton stalk lignins. By FTIR results, C=C bonds were found to be characteristic for antimicrobial lignin sample and it was suggested that these bonds might be the reason of the antimicrobial activity. By LC-MS qualitative mass analysis, antibacterial lignin fractions were found to be quite different from non-antibacterial lignin fractions. LC-MS results indicated that the antimicrobial lignin fractions might be lignin-derived oligomers and/or might be flavonoids. Cotton stalk lignin fractions demonstrated different antimicrobial activities depending on the method of isolation and chemical treatment.