Thermodynamic and Spectroscopic Studies of Pyrene Adsorbed to Titanium Dioxide from Water- Alcohol Mixtures

Xing Jin, Yoshihumi Kusumoto* and Katumitu Hayakawa

Pyrene was adsorbed to a TiO2 surface from water-alcohol mixture solutions at 25C and pyrene-TiO2 particles were recovered by filtration. We found that the adsorption process of pyrene to the TiO2 surface is cooperative and depends on the polarity of solvent. We also found that the surface of TiO2 thus recovered is relatively hydrophobic and pyrene is not decomposed but keeps its fluorescence characteristics on the spectral measurement under ultraviolet excitation

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Photoelectrocatalytic decolorization and cod removal from stimulated wastewater containing reactive dye

Taicheng An*, Guoying Sheng, Jiamo Fu1 and Xihai Zhu

Photoelectrocatalytic decolorization and Chemical Oxygen Demand (COD) removal from simulated wastewater containing reactive dye were experimentally investigated using a three dimensional electrode- slurry photocatalytic reactor. The experimental results indicated that the three dimensional electrode - photocatalytic reactor could significantly destroy the reactive Brilliant Red X-3B within a reaction time of 30 min, and had an effective removal of the color and the COD from the simulated dye wastewater. Much attention of the paper was paid to probe the effect of several affecting factors, such as airflow, cell voltage, pH value, initial concentration of dye and concentration of photocatalyst on the photo-electrocatalytic decolorization and COD removal efficiencies.

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Rapid Synthesis of Substituted Imides of Glutaconic and Homophthalic Acid in Microwave Oven using Solid Support

J.N. Gadre*, D.K. Vardhan, Late Radhika Nair, Mohit Mulay and Chaitanya Vaze

The rapid synthesis of N-aryl imides from 4(4-methoxyphenyl)-5H-Pyran-2,6dione (1) / isochroman-1, 3 dione (homophthalicanhydride) (4) and aromatic amines under microwave irradiation using neutral alumina as solid support has been described. The dry reaction condition under MWI resulted in increased purity of products with shorter reaction time, increase in safety and enhancement of chemical yields

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Degradation of VOCs by Photocatalytic Oxidation Reactor using TiO2 Pellets

Linda Zou*, Eric Hu, Yonggang Luo1 and SteveAtkinson

Volatile Organic Compounds (VOCs) are air pollutants that come from burning fossil fuels and industrial emissions. They have potentially adverse health effects being carcinogenic and highly persistent in the environment. The use of photocatalytic oxidation to remove VOCs has the potential to be applied in indoor air quality improvement and industrial emission control. A fixed bed photocatalytic reactor was designed and built. UV black light lamps were installed in the reactor to provide a source of UV radiation. A non-film titania media as pellets were placed on the three fixed beds within the reactor. Toluene and acetone were used as indicators of VOCs during the experiment. With a flow rate of 12.75l/min, the oxidation efficiencies were obtained at four different concentrations of acetone laden gas streams ranging from 40ppm to 250ppm. It was found that the lower the acetone concentration of the untreated inlet gas, the higher the oxidation efficiency. The oxidation efficiency was in the range of 4070% for various concentrations of untreated gases. Two concentrations of toluene laden gas stream were also tested using the same reactor. The oxidation efficiencies were found as 50% for 120ppm toluene gas and 45% for 300ppm toluene gas. It was found that the times required for toluene to reach oxidization equilibrium have been halved than for acetone gas stream. Other parameters such as flow rate and UV intensity were also altered to see their effects on the oxidation efficiency. A full spectrum scan was carried out using a Bio-rad Infrared spectrometer. It was found that the main components of the treated gas stream from the outlet of the reactor were CO2 and water along with small amount of untreated acetone. The suspected intermediates of aliphatic hydrocarbons and CO were found in very minimal amounts or undetectable. The research experiments supported that the TiO2 pellets can work effectively in a fixed bed photocatalytic reactor and achieve significant oxidation efficiencies for degradation of toluene and acetone as indicators of VOCs.

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Chromium (VI) Uptake by Nitrated and Sulphonated Coconut Shell Carbon

V. Selvi1* and G.P. Jeyanthi

The uptake of Cr(VI) using nitrated and sulphonated coconut shell carbon at various pH, adsorbent dose and initial Cr(VI) concentration has been studied. The characteristics of nitrated and sulphonated coconut shell carbons were also determined. The uptake percentage of Cr(VI) from solution was found to increase significantly with decreasing pH from 7.0 to 4.0 with both nitrated and sulphonated coconut shell carbon. The amount of Cr(VI) adsorbed on nitrated and sulphonated coconut shell carbon significantly increased with increasing adsorbent dose. The adsorption data of nitrated and sulphonated coconut shell carbon at different initial concentrations was fitted to both Freundlich and Langmuir adsorption isotherms

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Photochemical Modifications of Parthenin and Evaluation of the Products as Plant Growth Regulators

Rajat Rekha Setia, S. Garg and B.R. Chhabra*

Parthenin, one of the major components of Parthenium hysterophorus, is a pseudoguaianolide possessing amethylene-g-lactone moiety, cyclopentenone ring and a hydroxyl group. These moieties are responsible for the biological activity of the molecule. Hence, in order to explore the structure-activity relationship, parthenin was subjected to photochemical transformations. The derivatives thus obtained were tested for their biological activity, which included seed germination studies on Vigna radiata seeds and the effect on opening and closening of stomata of tradescantia leaf peelings.

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Kinetics of Hydrolysis of p-Nitrophenyl Acetate in the Presence of Lanthanides in Phosphate Buffer Solutions

K. Nakayama, I. Tari1, J. Sasaki, M. Sakai and K. Hayakawa*

Hydrolysis rate of p-nitrophenyl acetate (pNPA) and p-nitrophenyl phosphate (pNPP) was measured in the presence of lanthanide metal nitrates in phosphate buffer solutions at pH 9. The lanthanides used were Ce3+, Pr3+, Nd3+, Dy3+, Er3+ and Yb3+. Sodium hydroxide at pH 9 had minor effect on the hydrolysis rate, but a phosphate buffer at pH 9 had accelerated the hydrolysis of pNPA. The hydrolysis of pNPA was more accelerated by an addition of lanthanide nitrate in the phosphate buffer solution. A colloidal solution of lanthanide was formed in the phosphate buffer and the size was determined by an electrophoretic light scattering photometer. This acceleration effect was ascribed to the formation of colloidal complex of lanthanide with phosphate. The rate parameters, a and b, in Michaelis-Menten type rate equation correlate to the colloidal particle size of lanthanide in phosphate buffer.

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Kinetics and Mechanisms of Electron Transfer Reactions between cis-(2,2-bipyridine)(2,2- biquinoline) dichlororuthenium(II) and azido-, chloro-, and thiocyanatopentaamminecobalt(III) Complexes

Olayinka Oyetunji*, Bobby Ngake and Kelefeditse Ramontsho

Kinetic measurements have been made on the reductions of [Co(NH3)5X]2+ (X = N3 , Cl , and SCN) by cis-[Ru(bipy)(bquin)Cl2] (bipy = 2,2-bipyridine; bquin = 2,2-biquinoline) in solution media. The results obtained conform to simple second-order rate laws. At 25oC with [H+] = 0.10 mol dm-3 and I = 0.20 mol dm-3 , the three cobalt(III) oxidants are reduced with second-order rate constants, k2 (in dm3 mol-1 s-1) = 1.790.03, 8.890.12, and 9.530.14 for the azido, chloro, and thiocyanato complexes respectively. Activation parameters obtained areDH=/ (in kJ mol-1) = 16.950.94, 25.061.24,65.574.10 and DS=/ (in J mol-1 K-1) = 183.1639.38, -142.7110.63, and 5.990.42, each parameter being for the azido, the chloro, and the thiocyanato complexes respectively. The results are discussed to propose outer-sphere mechanism of electron transfer for the reactions. The relative reactivity of the ruthenium(II) complex is also discussed.

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The Impact of Mining and Metallurgical Activity of the Lavrion Sulfide Deposits on the Geochemistry of Bottom Sea Sediments East of The Lavreotiki Peninsula, Greece

A.Kelepertsis* and D.Alexakis

Chemical analyses of 20 bottom sea sediments from the Aegean region southeast of the Lavreotiki peninsula for the elements Pb, Zn, Cu, As, Mn, Ni, Co, Cr, Cd, Sr, Ba, Fe and Ca were undertaken. The mineralogical composition of the samples studied includes the following minerals: Mg-calcite, calcite, aragonite (Biogenic carbonate) and quartz, chlorite, albite, muscovite, pyrite and chamosite (Terrigenous detritus). The concentrations of heavy metals in the sediments studied range as follows: Pb (83-6791 ppm), Zn (51-9930 ppm), Cu (7-360 ppm), As (6-7616 ppm), Mn (174-10795 ppm), Ni (6-139 ppm), Co (2-35 ppm), Cr (3-197 ppm), Cd (0,4-44 ppm), Sr(105-2304 ppm), Ba (26-454 ppm), Fe (0,23-15,94 %) and Ca (10,93-29,43 %). Abnormally high values were found for the heavy metals in the samples proximal to the land (approximately 200 m from the coast) of the Lavreotiki peninsula. The geochemical variability in this region is affected by the two main sediment components: biogenic carbonate and terrigenous detritus (silicates and sulfides). The intercorrelated elements Pb, Zn, Cu, As, Cd, Co, Mn, Fe and Ba of the near-shore bottom sediments of eastern part of the Lavreotiki peninsula reflect their association with the Pb-Zn sulfide mineralization on land and its metalliferous wastes from the smelting activities

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Phytochemical Analysis of Selected Endemic and Indigenous Medicinal Plants of Mauritius and Rodrigues

F. B. Narod, A. Gurib-Fakim* and A. H. Subratty

Extracts obtained from forty-one selected endemic and indigenous medicinal plants of Mauritius and Rodrigues (2 tropical islands located in the South West Indian Ocean) were screened for the presence of 10 classes of secondary metabolites by standard phytochemical tests. Results from the phytochemical tests have revealed the presence of at least one or more of the following secondary metabolites, namely, saponins, flavonoids, phenols, terpenes and alkaloids in all extracts screened. Furthermore, tannins were found to be present in all extracts tested.

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Revealing a Methanol-water interaction in the Chromatographic Behaviour of some Drugs and Biologically Important Compounds

Marina D. Rukhadze*, George S. Bezarashvili, Nino G. Kokiashvili and Shota I. Sidamonidze

The dependence of chromatographic retention factor of twelve compounds of different kind (anionic, cationic, neutral and zwitterionic nautre) on the mobile phase composition in conventional reversed-phase HPLC by using two factoral mathematicaldesign of a second order was investigated. The contents of methanol and water in mobile phase were selected as principal factors. On the basis of planned experiments the second order regression equations were deduced. The significant interactions between principal factors were revealed which are positive for anionic solutes, negative in case of cationic samples and are equal to zero regarding neutral compounds. The probable mechanisms are proposed in order to describe the retention changes of compounds of different nature due to their interaction with both methanol-water complex formed in the mobile phase (homogeneous mechanism) and silanol groups of stationary phase modified by this complex (heterogeneous mechanism). The response (retention factor, K) surfaces for each compound were constrained in three-dimensional factoral space.

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Effect of collection period on the flavour profiles of the leaves of myrtle tree (Myrtus communis L.) growing wild in Turkey

Musa zcan* and Jean- Claude Chalchat

The constituents of essential oils isolated by hydrodistillation of the leaves of myrtle (Myrtus communis L.) from Turkey have been examined by GC-MS. Essential oil contents on a dry weight basis of leaves from myrtle were 1.46%, 1.53% and 1.47% respectively. A total of 58 components were identified by GC-MS analyses, the main components representing 84.21%,83.46% and 83.01% of the oils were identified to a-pinene (21.22%, 23.87% and 18.56%), 1,8-cineole (22.34%, 25.27% and 24.96%), linalool (19.08%, 16.60% and 19.56%) and a-terpineol (6.93%, 7.05% and 8.23%) for June, July and August respectively. The oils consisted of monoterpenic hydrocarbons, oxygenated monoterpenes and sesquiterpene hydrocarbons. The essential oil composition varies qualitatively and /or quantitatively with different collection period. Results confirm the effects of collection time on the oil content and composition

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Short Communication : An oxaza cyclohexane moiety with antimicrobial and antifeedant activity from nutrient stress callus of Salacia beddomei

M.A. Deepa*, V. Narmatha Bai1 T. Suresh, T. Dhanapal and P.S. Mohan2

An oxaza cyclohexane derivative was isolated from the nutrient stress stem callus of Salacia beddomei and the partial structure of the compound i.e., 2-(21-pyrrolyl)-1,3-oxaza cyclohexane was characterized by spectroscopic methods. The compound containing oxaza ring system was found to be a potential antimicrobial agent. It exhibits significant antifeedant and insecticidal activity with 100% morality on Spodoptera litura the cotton leaf worm.

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Short Communication : Role of Internet in the Studies of Chemical Kinetics

S.S.Verma

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