Research Journal of Chemistry and Environment

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Research Journal of Chemistry and Environment

Study of Photocatalytic Degradation of an Anionic Surfactant

A.Boukhennoufa, M. Bouhelassa and A. Zoulalian

The aim of this work is to improve the treatment of waste water containing the surfactant such as Sodium Dodecylbenzene Sulphonate. The destruction of this anionic surfactant by photocatalytic system has been studied in a semi-pilot scale in a recirculation apparatus including a set of two reactors in series: a mechanically agitated one in which the three phase contact gas-liquid- solid is made followed by a photochemical tubular one receiving an aqueous suspension of TiO2 particles through a double parietal envelope with a mercury steam pressure lamp in its centre sending out ultra violet radiation. The sodium dodecylbenzene sulphonate is decomposed efficiently within 5 hours of irradiation. The effects of some physical parameters such as the catalyst concentration, the pollutant initial concentration, the oxygen partial pressure and the absorbed light intensity are examined. The pH decrease shows that the TiO2-surfactant aqueous dispersion system becomes significantly acidic under illumination and some adsorption of NaDBS on the TiO2 surface before illumination is noted. The surfactant photodegradation kinetic can be modelled in terms of the Langmuir-Hinshelwood equation.

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Use of Natural Zeolites for Wastewater Treatment

G. Baghino, R. Peretti, A. Zucca, A. Serci, M.L. Fercia and R. Lonis

The paper describes the results of an investigation conducted for the purpose of exploring the possibility of using a natural zeolite, occurring in central-northern Sardinia, for removing the ammonium ions contained in effluents discharged from wastewater treatment plants. Laboratory tests have been carried out on samples of wastewater effluents from a treatment facility in different sized columns containing appropriately ground zeolitic material, either untreated or in the Na-exchanged form. The results demonstrate the efficacy of the zeolite tested, especially in its Na-exchanged form, in removing the ammonium cation and the possibility of employing this mineral in municipal and industrial wastewater treatment processes

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Deviation Method for the Measurement of Refractive Index of Liquids using a Helium-Neon Laser and two identical Prisms

Shyam Singh

A simple method for the measurements of refractive index of liquids using a low power helium-neon laser emitting a continuous beam of wavelength 632.8 nm and two identical hollow (or one hollow and one solid) prisms has been proposed. The refractive index of liquids can be measured without knowing the refractive index of prism. The experimental values for some liquids have been presented.

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Biophysical Characterization of Protease Induced Enzymatic Degradation of Poly-3-hydroxy Butyric Acid

Sumana Chatterjee

The crystalline extracellular poly 3-hydroxy butyric acid, obtained from Metabolix Inc. was dissolved in 50% TFA and thereafter taken into aqueous phase in order to study the effect of protease upon the compound. Biopol- protease interaction is studied through light scattering both static and dynamic, along with NMR. Static light scattering shows a consistent decrease of the intensity of the scattered light upon the addition of the protease. Dynamic light scattering also supports the evidence. This points out towards a reduction of particle size due to Biopol- protease interaction. NMR studies of biopol –protease mixture repeatedly show emergence of new peaks and increase in the multiplicity of the peaks. This indicates protease cleavage to give new compounds. Biopol soaked in buffer alone at 35 degrees, mechanically shaken and treated with proteolytic enzyme showed peaks at the finger –print region of the spectrum, which suggest protease mediated degradation of the polymer surfaces of the crystalline extra cellular poly 3-hydroxy butyric acid. The protease used is the eukaryotic trypsin and bacterial protease subtilisin.

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Trace Metal Concentrations in Wet and Dry Atmospheric Deposition in Thessaloniki, Greece

Ch. Anatolaki and R. Tsitouridou

Al, Cd, Cr, Fe, Mn, Ni, Pb and Zn were determined in wet and dry deposition samples collected in an urban site of Thessaloniki, Greece, for a period of one year (April 2002 to April 2003). The sampling was performed by using a conventional wet/dry collector. Average trace metal concentrations, particularly in dry depositions, were found in relatively high levels compared with other urban areas. Annual dry deposition fluxes were generally higher than the corresponding wet depositions, particularly for the soil related elements, probably due to the dry weather conditions prevailing in the country during the rainless period. The study of crustal enrichment factors indicated the considerable enrichment of the metals from crustal materials, whereas anthropogenic emissions were present in both depositions. Finally, correlation matrix for all the elements in both modes and principal component analysis were used to obtain information for possible sources of the close and greater area

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Mathematical Modelling of Thermophilic Denitrification by Bacterial Consortium under Anaerobic Conditions

M. Natcheva, V. Beschkov and Ts. Sapundzhiev

Nitrogen containing ions such as nitrate and nitrite occur widely in a variety of process streams, such as those coming from the extensive use of fertilizers. These species can have serious consequences when released in the environment, due to the possible health effects for many organisms including humans. A key problem consists in the reduction of nitrate to nitrite, the latter being considerably more toxic than nitrate itself.

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Intercalation of Pyridine Derivatives into the Interlayer Spaces of Cu(II)-Montmorillonites

E. Jóna, E. Rudinská, M. Sapietová, M. Pajtášová, D. Ondrušová, V. Jorík and S.C. Mojumdar

Intercalation of pyridine (py), 4-methylpyridine (4-Mepy) and 4-ethylpyridine (4-Etpy) into the interlayer spaces of Cu(II)-montmorillonite (Cu-MMT) was investigated. The successful intercalation of these compounds through coordination to the interlayer Cu2+ cations was confirmed by powder X-ray diffraction and infrared spectroscopy of the products. The presented solid - gas intercalation of pyridine derivatives and in situ complex formation in the interlayer spaces of montmorillonite is a feasible way to prepare clay-coordinaton-intercalation comounds, which cannot be obtained in conventional ion exchange reactions.

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Radioprotective Role of Centella Asiatica (Linn.) against Gamma Radiation Induced Hepatic Injury

Radha Sharma and Jaimala

In order to search a potent natural radioprotector a well known medicinal plant Centella asiatica (Linn.) was tested for its modulatory activities against gamma radiation induced alterations in the liver of Swiss albino mouse. Body weight, total protein and cholesterol content of the liver were assessed after irradiation with and without Centella asiatica pretreatment. Body weight and protein content in the mouse liver increased after exposure to sublethal doses of whole body gamma radiation exposure. However, this tendency of increase was lesser in irradiated but Centella asiatica pretreated group (at the dose rate of 100 mg/kg body weight, one hour prior to irradiation). The subsiding tendency of cholesterol content after irradiation reverts to near normal level in Centella asiatica pretreated group. The present study on body weight and liver indicates that Centella asiatica pretreatment protects against harmful effects of radiations.

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Global Solar Radiation Attenuation by Dust and Polluted Air in Zarqa Region, Jordan

M.H. Barakat and N.I.B. Jallo

The densely populated Zarqa city (Latitude 32.2N Longitude 36.35E) is located 30 km to the NE of the capital Amman in a highly disturbed desert land. In addition the area accommodates about 60% of the Jordan’s industrial establishment including Oil Refinery, the major waste water treatment plant of Alsamra and the recently closed municipal solid waste dump site. The above factors were thought to substantially contribute to atmospheric aerosols pollution. In this study the monthly averaged Linke turbidity for Zarqa region is determined using global irradiance measured by GS1 Solarimeter. The air data of cloudless days along period of two years from 1st January 2001 to 31st December 2002 was used in this determination. The results indicate that the maximum turbidity was observed in the summer time with an average value of 4.2. The air turbidity shows an inverse relation to wind speed. Variation of global radiation through the days of week shows that the solar attenuation is highest on Tuesday. The clearness index was found to be around 0.66 in clear days. A best fit equation between clearness index (k) and elevation angle (h) was expressed as (k= 0.085 ln(h)+ 0.3509) . All the findings implied that the area is moderatly polluted.

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Phase Equilibrium in the System Ln-Mn-O VII. Ln = Eu and Y at 1100°C

Kenzo Kitayama, Takuya Yazaki, Toshiharu Fukushima, Kazuaki Matsui, Shinsuke Sami and Masahiro Nakamura

Phase equilibrium was established in Eu-Mn-O and Y-Mn-O systems at 1100°C at the oxygen partial pressures ranging from -log (Po2/atm) = 0 to 12.00, and phase diagrams for the corresponding Ln2O3-MnO-MnO2 system at 1100°C were constructed. Eu2O3, MnO, Mn3O4, EuMnO3, and EuMn2O5 phases were found to be stable in the Eu-Mn-O system, and Y2O3, MnO, Mn3O4 and YMnO3 phases were stable in the Y-Mn-O system, but YMn2O5 was not stable under the present experimental conditions. Ln2Mn2O7, Ln2MnO4, Mn2O3, and MnO2 were not found in either systems. The EuMn2O5 phase has nonstoichiometric composition. Lattice constants of EuMnO3 and YMnO3, which quenched at two different oxygen partial pressures, and of EuMn2O5 quenched in air were determined. Spacings and relative intensities of EuMn2O5 were determined based upon those of SmMn2O5 and compared with previous values. The standard Gibbs energy changes of the reactions appearing in the phase diagrams were also calculated. The relationship between the tolerance factor of LnMnO3 perovskites and DGO values for the reaction, 1/2 Ln2O3 + MnO + 1/4 O2 = LnMnO3 , was shown to be proportional. DG0 values of HoMnO3, YMnO3, and YbMnO3 of the transition from hexagonal to orthorhombic system were deduced at 1100°C with an assumption.

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Equilibria in the alcoholysis reactions of terephthalic esters and in chemical valorisation of polyethyleneterephthalate waste. II. Application to monodisperse polyols synthesis processes

Gilles Tersac and M. Billiau-loreau

The depolymerization of polyethylene-terephthalate (PET) by alcoholysis is an easy operation and gives interesting perspectives for the valorization of waste. One of them is the manufacture of Aromatic Polyester Polyols (APP), that often needs a supplementary esterification step. The reactive species being composed of esters and alcohols, all possible alcoholysis reactions happen, whether wanted or not. Finally a complex blend of dihydroxyl ended molecules follows characterized by a large distribution of both chemically different units and molecular weight. The physicochemical properties of the final product depend largely on the chemical composition. Examples of adaptation of processes are given, within either thermodynamic or kinetic control. “Monodisperse” polyols may be obtained by, first glycolysis/esterification within high molar ratio of glycolic/diacidic units and, second, stripping off the free glycols excess. Alternatively, stripping off the formed monoethyleneglycol allows the accessibility to polyesterdiols lacking in ethanediyl units.

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Review Paper : Review on Applications of Bioremediation Methods For Decontamination of Soils

Zareen Khan and Anjaneyulu Y

Decades of industrial activities such as mineral extraction, smelting, oil refining, engineering and gas manufacturing have left many sites in the world contaminated with oils, solvents, metals and other pollutants. Leaks, spills and disposal practices at factories, warehouses, laboratories, garages, farms, workshops, storage depots and military bases have all added to the problem of contaminated land. The past two decades have seen a tremendous upsurge in the search for cost effective and environmentally sound alternatives to traditional methods for dealing with the wastes. Research and technology development and implementation to address waste issues now rank very high among the fastest growing activities in the world. Containment, excavation and disposal have been the most commonly used technologies for the treatment of contaminated land. However the increasing costs of long-term monitoring, excavation, transport, replacement, soil and landfill disposal are encouraging the use of alternative methods of cleaning up contaminated land. Bioremediation which involves the use of microbes to detoxify and degrade environmental contaminants has received increasing attention as an effective biotechnological approach to clean up a polluted environment. The present paper reviews the several bio-remediation technologies and practices that take advantage of natural systems and processes to clean up pollution.

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