Research Journal of Chemistry and Environment

Indexed in SCOPUS, Chemical Abstracts Services, UGC, NAAS and Indian Citation Index etc.

Research Journal of Chemistry and Environment

Microamperometric Method for Hydrogen Peroxide Determination in Flow Injection Analysis

O. Largiuni*, R. Bocciolini, S. Becagli, R. Traversi and R. Udisti

A sensitive method for the hydrogen peroxide amperometeric determination in aqueous samples by Flow Injection Analysis has been developed. A thin layer microcell with a platinum working microelectrode has been used. The developed method has a detection limit of 0.08 mg l-1 and a precision of 7% at 1 mg l-1 level (< 1% for concentration > 10 mg l-1). The calibration graph is linear in over the range 1-34500 mg l-1. The sensitivity, rate of sample analysis, ease of use and small volume of sample requested make this method ideal for hydrogen peroxide determination in precipitation samples with concentration from very low to very high by Flow Injection Analysis. The method has been applied to analysis of 153 snowpit samples from Antarctica and the results have been compared with those obtained with fluorimetric method.

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Settling in a Periodic Array of Eddies: A new procedure of Separation and Classification of Heavy Particles Suspended in a Fluid

U.Sánchez* and M. J. Moreno-López

Disperse multiphase flows are very common in the environment and in many industrial processes. Existing procedures of particle-fluid separation do not sort particles with different characteristics. We propose a new procedure, which differentiates small heavy particles suspended in a fluid depending on their inertia values. For that purpose we simulate a velocity field generated by a 2D array of vortices periodically repeated in space in two cases: firstly all the neighbouring vortices swirling alternatively cyclonically and anticyclonically and secondly all the neighbouring vortices swirling in the same sense (counterclockwise). In the first case, for small particle inertia the particles follow the flow streamlines surrounding the vortices, but for larger inertia values, every time the distance between the particle and the vertical row of vortices is greater and at last all the particles settle in the central region of low vorticity situated between two vertical rows of vortices due to an inertial bias. In the second case, the behaviour of the particles is the same as in the previous one for small or moderate particle inertia values, but for sufficiently large particle inertia the particles do not settle in the central region of low vorticity, they settle on some isolated curves which limit some regions of low vorticity where particles can not enter. As larger is the particle inertia, larger is the width of those regions. At the same time, some empty regions situated under each vertical row of vortices appear. As larger is particle inertia, smaller is the width of these empty regions because the influence of the vorticity field is smaller. Therefore if we know the particle inertia we will know the position in which it will settle and vice versa, so this fact suggests to develop a mechanism to sort particles with different inertia values.

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Phase Behavior and Microscopy Propertiesof Batyl Alcohol

K.Anuar*, C. S. Lim, K. Dzulkefly and I.Zahariah

Batyl alcohol (BA) is widely used in cosmetic products, little is known about its phase behaviour and its structure in ternary systems. Phase diagram of BA/Isopropyl Myristate (IPM)/H2O were constructed at 80°C and the phase changes were observed under a polarizing microscope. In the ternary systems, lamellar and hexagonal areas were found in 90/10 and 100/0 mixtures of BA and IPM respectively. They were identified by their patterns of Maltese crosses and fan structures respectively. A focal conic fan-like and pseudo-isotropic texture was also found in this system. This phase was observed before entering the liquid crystal area. Further addition of either Medium Chain Triglyceride (MCT) or Propylene Glycol (PG) to the system resulted in isotropic and two-phase areas being formed instead of a liquid crystalline structure.

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The Preparation and Structural Studies of bis(aquachloro)chromium(III) bis(m-hydroxy) hippuratohydroxyaquachromium(III) Complex

G. Kumar

The preparation and structural studies of bis(aquachloro) chromium(III) bis(m-hydroxy) hippuratohy droxyaquachromium(III) complex have been carried out by elemental analysis, IR, UV spectra and magnetic measurements. In this complex, hippuric acid has been found to act as a bidentate ligand and the coordination occurs both from carboxylate oxygen and nitrogen of the amido group. The complex has been suggested to show octahedral structure.

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Tarnishing of Silver in Telephone Switching Centers in Japan

Masamitsu Watanabe

The tarnishing of silver exposed in our nine telephone switching centers has been studied. The silver tarnish rate was calculated from the amount of sulfur detected on the silver surface determined by x-ray fluorescence analysis on the assumption that the sulfur existed as silver sulfide (Ag2S). The tarnish rates in the telephone switching centers obeyed a lognormal approximation with a high correlation coefficient. The geometric means of the tarnish rates in urban, rural, and hot spring areas were 3.23, 3.62, and 44.01 nm/30 days, respectively. The tarnish rates obtained in our telephone switching centers in urban areas were an order of magnitude lower than the rates reported for the US and Southeast Asia. This was attributable to the lower hydrogen sulfide (H2S) concentration. The fast tarnish rates at one rural site were considered and found to result from a high concentration of carbonyl sulfide (COS). COS may account for the silver tarnishing in our telephone switching centers.

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The contribution of Geophysical Methods in the determination of Aquifer Parameters: the case of Mornos River Delta, Greece

Ioannis F. Louis*, George A. Karantonis, Nikolaos S. Voulgaris and Filippos I. Louis

Knowledge of hydraulic conductivity and transmissivity is essential for the determination of natural water flow through an aquifer. Although these characteristics are mainly deduced from pumping test analysis, attempts have been made to employ geophysical methods in order to reduce the amount of hydrogeological observations and the resulting cost. Use of layer thickness, as derived from the interpretation of resistivity soundings data and hydraulic conductivity calculated on the basis of both hydrogeological and geophysical data led to the calculation of aquifer transmissivity. This technique was used for the determination of aquifer parameters in Mornos River Valley at central Greece. Maps of the basement relief, resistivity, transmissivity and Transverse Resistance provided the means to identify areas where the aquiferous zone is prolific. The good agreement between aquifer hydraulic conductivities obtained from the resistivity soundings interpretation and those deduced from pumping test analysis emphasizes the potential of the methodology.

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A study of air pollution on Kharg Island in the South Iran

S. Tasharrofi*, A. Dahaghin, H. Kazemi and M. Farhadynya

Nowadays the development of oil industry has severe effects on environmental pollution. The problem begins from simple crude oil separation units to large refineries. As a case study we chose Kharg Island where several production units and oily pits are active. This paper is in connection with a research work in two successive years 2000 and 2001, in which monthly concentrations of total active sulfur compounds were measured in six stations in parallel. In this research work, sources, effects and standards of pollutants are investigated and their relation to emission sources have been evaluated. Then the results of measurements in different stations are compared with each other and with standard limits.

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Study of Photogalvanic Effect in Azur C–Nals-ascorbic Acid System

K.R. Genwa* and Anju Chouhan

The Photogalavanic effect was studied in a photogalvanic cell containing NaLS–Ascorbic acid and Azur C as a surfactant, reductant and photosensitizer respectively. The photopotential and photocurrent generated by this system were 623.0 mV and 145.0 mA respectively. The observed conversion efficiency was 0.4567% and fill factor was determined as 0.30. The cell performance was 95.0 minutes in dark. The effect of different parameters on the electrical output of the cell were observed, current–voltage characteristics of the cell have also been studied and mechanism has been proposed for the generation of photocurrent in photogalvanic cell. Maximum power obtained from this cell was 47.50 mW.

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Use of 2, 4 –Dihydroxybenzophenone Oxime as a Reagent for Extraction and Spectrophotometric Determination of Palladium (II)

R.S. Lokhande*, Ujwala Patil and Sheetal S. Dapale

2,4–Dihydroxybenzophenone Oxime(DHBPO) was synthesized and its characterization study was carried out using elemental analysis, IR, NMR techniques. The reagent was proposed as extractant for development of new extractive spectrophotometric method for determination of Pd (II) metal. The reagent complexes with metal to produce yellow coloured complex which was then extracted into Butan-1-ol at pH 4.0. The complex is having absorption maxima at 410 nm. The molar absorptivity of the extracted species is 0.672 x102 L mol-1 cm-1 and sensitivity is 0.06729 mg/ml. The method permits separation and determination of Palladium catalyst and binary mixture.

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Mass Spectrometric and I R spectroscopic study of the destruction of environmentally hazardous Indanthrene Red FFB a textile pollutant

L. Gomathi Devi * and R.Geetha Balakrishna

Photocatalytic oxidation of organic pollutants over nano particles of TiO2 prepared by gel to crystalline conversion was investigated as a potential method for destroying textile pollutant Indanthrene Red FFB. Surface morphology of synthesized anatase phase of TiO2 was studied using SEM analysis and X-ray diffraction studies. Photodegradation path is followed by UV Visible spectroscopy, Mass spectrometry and Infrared (FTIR) spectroscopy. There are significant quantities of intermediates like phthalic acid, amino substituted phthalic acid, aniline, phenol and benzene. These products have also been rationalized on the basis of chemical reaction mechanism in which anthraquinone dye molecules are oxidized in a chain reaction involving radicals. A kinetic model is thus formulated based on the results.

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Possibilities of using Red Mud as Raw Materials Mixture Component for Production of Bricks

M.M. Krgovic*, N.Z. Blagojevic, Z. K. Jacimovic and R. Zejak

Red mud is a bye-product of Bayer process for obtaining alumina (solid residue of dissolution of bauxite). In this paper possibility of using red mud as a component of raw materials mixture for obtaining bricks has been investigated. By using red mud cheap raw material for building construction and ceramics would be obtained and, at the same time, the problems (air, underwater and soil pollution) of environmental protection, which can be posed by frequent disposal of red mud into the pools, would be solved. On the basis of all the results of the investigations and their analysis, it can be concluded that red mud can be used as a component of raw materials mixture for production of bricks satisfying mechanical characteristics, shrinkage and porosity of sintering products.

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Removal of Zinc from Waste water

B. K. Bhattacharya*, S. K. Das and S. N. Mandal

Zinc is a very widely used metal. The main source of aquatic contamination of zinc are the metal production units and the other industries wastes like pharmaceuticals, electroplating, paints and pigments, which use metal and its compounds. Zinc is present in the effluents from the electroplating, metal processing, pigment manufacturing, textile and dye industries etc. which cause serious problems to the environment. In an aquatic environment, high concentrations of heavy metal through water and sediment phase tend to accumulate in different tissues of the body of fishes and other aquatic lives and thus bio-accumulated and disturbing the natural equilibrium of an aquatic environment. Symptoms of zinc toxicity include irritability, loss of appetite, nausea. Increased concentration of zinc is dangerous to human beings. In the presents study an attempt has been made to remove zinc from aqueous medium by using fullers’ earth as an absorbent. The effects of pH, initial concentration of zinc, contact time, adsorbent doses and isotherm models were studied in batch processes

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