Research Journal of Chemistry and Environment

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Research Journal of Chemistry and Environment

Letter to the Editor: Biofuels – Bane or Blessing ?

Pillay A.E., Elkadi M. and Fok S.

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Influence of Eh/pH – Barriers on Releasing /Accumulation of Manganese and Iron at Sediment-water Interface

-Shrestha Reena Amatya* and Sillanpää Mika

The remedy of contaminated soils/sediments with heavy metals and organic compounds is one of major and permanent environmental challenges today. In the most mining areas we found significant concentrations of metals such as lead, copper, chromium, zinc, cadmium, iron, manganese, cobalt, nickel, mercury, arsenic and also halogenated organic compounds and radionuclides. Of those, manganese and iron are always present in huge amount although they are essential metals for all living beings including humans. But, they are very excellent scavengers for other toxic metal and pathogenic microorganisms in the sediment. Therefore,the mobilisation and accumulation of Mn and Fe at the sediment-water interface was studied varying different positions and conditions of the electrode arrangement. The tests were carried out with a natural heavy metal containing in the dredged sediment from the river Weisse Elster (Germany). The electrokinetic experiments have been performed in columns filled with sediment using electrodes made of conductive polymers (polyethylene with carbon black) at a maximum current density of 0.5mA/cm2. The experimental results suggest that the electrokinetic mobilisation and accumulation of Mn and Fe highly depend on chemical factors e.g., pH and redox potential. The sorption of Mn and Fe was very high in the pH range > 4.5. As expected, a high mobilisation of Mn and Fe was seen in the case of the experiment with the anode at the sediment because the pH value was lower than mentioned above. On the opposite, the best conditions for the Mn and Fe-immobilisation are high pH-values (cathode at the sediment). The electrochemically initiated pH- and Eh-barrier is a practicable method to accumulate Mn and Fe and to support the in-situ-cleaning of the sediments.

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CO2 Removal Rate in Earth’s Atmosphere

Van Hise James R.

We compute the apparent rate of removal for CO2 in Earth’s atmosphere using measured atmospheric CO2 concentrations and estimates of annual carbon releases to the atmosphere for the period since the year 1850. We do this using two methods both of which assume a first order removal rate of that CO2 above an equilibrium value. Method 1 gives an average lifetime, over the last 100 years, of 45 years and Method 2 gives average lifetime, over the last 100 years, of 41 years.

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Interactions of Different Heterocyclic Compounds with Monoionic Forms of Montmorillonite IV. Intercalation of Benzimidazole into the Interlayer Space of Ni(II)-Montmorillonite

Jóna E., Sapietová M., Šnircová S. , Jesenák K. and Mojumdar S.C.

Interactions of benzimidazole with Ni(II)exchanged montmorillonite were studied. Diffraction analysis indicated that benzimidazole molecules are intercalated into the interlayer spaces of montmorillonite. Infrared spectral data and the analytical characteristics have shown that different type of interactions of benzimidazole are connected with different reaction conditions (acid, neutral or basic solution). In an acid solution, an ionic exchange of benzimidazolium ion for Ni(II) ions takes place. In a nearly neutral and basic solution, benzimidazole molecules are coordinated to Ni(II).

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Direct Synthesis of Dimethyl Carbonate (DMC) from Methanol and Carbon Dioxide under Pressure and UV Irradiation

Wang X. J., Xiao M., Wang S. J., Lu Y. X. and Meng Y. Z.

A nano-scale photo-catalyst of supported copper modified (Ni, Mo, O) semiconductor complex was synthesized and its photo-catalytic activity was investigated on the direct synthesis of dimethyl carbonate from CO2 and CH3OH. The technologies of temperature programmed reduction (TPR), X-ray diffraction (XRD), Ultra-violet visible drift reflection spectra (UV-vis DRS) and transmission electron microscopy (TEM) were used to fully characterize the photo-catalyst. The pressure dependency of methanol conversion was studied at 120°C under a varying pressure from 1 to 18 atmospheres. The experimental results demonstrated that the catalytic activity was enhanced by ultraviolet (UV) irradiation when compared with the pure thermal reaction under the same reaction conditions. Both high methanol conversion of higher than 6.47% and DMC selectivity of 83.9% were afforded under the optimized catalyzed pressure of 6 atmospheres.

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Date Palm Leaflets: BioIndicators of Total Mercury in Soil and Assessment of the Potential for Biomagnification of Total Mercury along a Food Chain

Williams J. R., Pillay A. E. and Yaghi B.

This study was undertaken over several months to investigate total mercury levels in previously unstudied date palm leaflets and associated soil. The cold vapour atomic absorption technique at 253.7 nm was employed for the quantitative analysis of the leaflets and soil. Date palms of the Fard cultivar were found to accumulate mercury slightly in their leaflets. Average mercury levels in the leaflets were almost twice the concentrations found in the surrounding soil. This information could be useful when prospecting for mercury ores in soils or as indicator of mercury levels in rocky soils where conventional soil samplers fail. In some cases, mercury levels in the leaflets were above the recommended maximum for plant leaves of 40 mg/kg dry mass. This is a cause for concern because livestock are fed partly on date palm leaflets. Additionally, insects eat the leaflets and are themselves devoured by birds. The possible consequence in both cases is biomagnification of mercury along the food chain.

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Heavy Metal Contamination of Water in Coastal and Inland Areas of Vasai Region, India

Mehta B.H. and Amin C.S.

This research paper presents the monitoring results of heavy metal pollution across seven sampling stations in Vasai region located on the western coast of India. The concentration levels of nine metals (Fe, Cr, Ni, Cu, Pb, Zn, Co, Al, Cd) were detected. The heavy metals were detected using AAS- ICP-AES methods. The investigation reveals that water at the inland sites is significantly contaminated with Zn, Cr, Ni and Cu being the major pollutants. High levels of Fe and Al were observed at the coastal sampling sites. Anova was used to determine significant differences between the sampling stations.

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Synthesis, Characterization and Antimicrobial Efficacy of Zr(IV), Rh(III), Th(IV) and UO2(VI) Complexes with (2E)-2-(4-hydroxy-3-Methoxycyclohex-3-enylidene)-1-(3, 4-dimethylphenyl)ethanone and (1E,6E)-1, 7-bis(4-hydroxy-3-methoxy phenyl) Hepta-1, 6 diene-3, 5-dione

Arun V.S., Naik Nagaraja and Gnanendra C.R.

Mixed ligand complexes of Zr(IV), Rh(III), Th(IV) and UO2(VI) (2E)-2-(4-hydroxy-3-methoxycyclohex-3-enylidene)-1-(3,4-dimethylphenyl)ethanone (hmed) and (1E, 6E)-1, 7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3, 5-dione(bhmd) have been synthesized. These complexes have characterized using elemental analysis, IR, TGA, magnetic susceptibility and molar conductivity measurements. These studies revealed that they are having octahedral geometry of the type [MLL’(H2O)2Cl], where, M= Zr(IV), Rh(III), Th(IV) or UO2(VI), L=hmed and L’=bhmd. The newly isolated metal complexes are biologically active. The in vitro antifungal and antibacterial studies indicated that these complexes are potent against a few tested microorganisms.

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Hydrogen Plasmas Generated Using Certain Group I Catalysts show Stationary Inverted Lyman Populations and Free-Free and Bound-Free Emission of Lower-Energy State Hydride

Mills R. , Ray P. C., Nansteel M., Good W., Jansson P., Dhandapani B. and He J.

Rb+ to Rb2+ and 2K+ to K + K 2+ each provide a reaction with a net enthalpy equal to the potential energy of atomic hydrogen. The presence of these gaseous ions with thermally dissociated hydrogen formed a plasma having strong VUV emission with a stationary inverted Lyman population. Significant Balmer a line broadening of 18 and 12 eV was observed from a rt-plasma of hydrogen with and respectively, compared to 3eV from a hydrogen microwave plasma. The reaction was exothermic since excess power of about 20 mW/cc was measured by Calvet calorimetry. We propose an energetic catalytic reaction involving a resonance energy transfer between hydrogen atoms and Rb+ or 2K+ to form a very stable novel hydride ion. Its predicted binding energy of 3.0468 eV with the fine structure was observed at 4071 Å and its predicted bound-free hyperfine structure lines EHF = j2 3.00213X 10-5 + 3.0563eV(j is an integer) matched those observed for j = 1 to j = 37 to within a 1 part per 104. Characteristic emission from each catalyst was observed. This catalytic reaction may pump a cw HI laser.

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Studies on Stability Constants of Binary and Ternary Complexes of 5-chloro-2 {[(2-hydroxyethyl)imino]methyl}-phenol with CoII, NiII, CuII and ZnII in presence of other Chelating Agents

Reddy P. Madhava1, Rao B. Krishna, Narender P. and Satyanarayana B. 2*

The stability constants of 1:1 binary MII-CHAEA and 1:1:1 ternary [M11-CHAEA-A] chelates [where M11=CoII, NiII, CuII and ZnII; CHAEA = 5-chloro-2 {[(2-hydroxyethyl)imino]methyl}a-phenol; A = Glycine (gly), -alanine (ala), Proline (pro), Histidine (hist), Iminodiacetic acid (IMDA) and 2, 2’-Bipyridyl (bipy)] have been determined pH metrically in 50% (v/v) aqueous 1,4-dioxane medium at 300C and I = 0.1 M KNO3. The ligand CHAEA in presence of gly, ala, pro, hist, bipy and IMDA coordinates in stepwise manner with all the transition metal ions. The order of formation constants of binary as well as ternary chelates follows Irwing-William order [CoIIZnII]. The formation of binary complexes are more favourable over ternary complexes. The computer simulated distribution of the complexes in solution has been evaluated.

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Effect of Oxidant Treatment of Date Stones Activated Carbons in Treatment of Water

Merzougui Zoulikha and Addoun Fatima

Three activated carbons have been prepared from date stones, by carbonisation without adjuvant and by chemical activation with ZnCl2 and KOH. According to the adjuvant, the activated carbons present different porosities. Chemical activation of the date stones with KOH produces an activated carbon having mesoporosity developed as well as in the ZnCl2 activation. This last process led also to develop the microporosity more than KOH activation. The surface area, pore texture, chemical analysis and dosage of Boehm, of the activated carbons have been studied. Adsorption at 298K of phenol, p-cresol and o-chlorophenol from aqueous solutions on activated carbons has been studied. The adsorption capacity of the activated carbons depended on the surface area and porosity of the carbon, the solubility of the phenols compounds, and the hydrophobicity of the substituents. The modification of the porous texture and the chemical nature of the surface of activated carbons have been realized by oxidization with nitric acid. This oxidization leads to a considerable decrease of the surface area SN2 and of the microporeux volume W0, fixing a large amount of oxygen surface groups who influence negatively to the properties of adsorption of the activated carbons. A heat treatment of these activated carbons leads to a reduction of the concentration of the oxygen groups and therefore an amelioration of the adsorption capacity.

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Sorption of Monuron Herbicide in Some Selected Mineral Sorbents

Tajeddine Laila, Mountacer Hafida* and Sarrakha Mohamed

The environmental fate of phenyl urea herbicides in ecosystems is strongly influenced by their sorption on natural sorbents. Clay and sediment colloids are the most important contributors in fixing pesticides and other organic compounds. The present work studies the adsorption of monuron in some mineral sorbents (clays extracted from tow Moroccan soils (CESS and CEBS) and tow commercial clays type montmorillonite M and kaolin Ka). Clay characterization was done using Infrared spectroscopy and X-ray powder diffraction. Batch sorption experiments were carried out under various conditions to determine the influence of solution chemistry (herbicide concentration, pH and solid-liquid ratio). The adsorption data could be fitted with Freundlich isotherms and the coefficients indicated favourable adsorption of monuron on all clays studied; Kf values varied according clay type: 9.6 and 19.4 for kaolin and montmorillonite respectively; 6.5 and 10.6 for CEBS and CESS respectively.

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The Study of Sr2+, NO3- and PO43- Removal from the Simulated Wastewaters using the Cartrige Filtration Generated from the Native and ODA-clinoptilolites

Sabová Lenka*, Chmielewská Eva and Gáplovská Katarína

The study of cations and anions removal and column dynamics was investigated using a clinoptilolite-rich tuff from Turkey (Eskisehir deposit, Central Anatolia) and Slovakia (Nižný Hrabovec deposit). The Slovak clinoptilolite was modified with octadecylammonium (ODA) surfactant in order to enhance adsorption properties. The surface of zeolite under the current modification revealed coverage of ODA bilayers. This phenomenon indicated that the orientation of the ODA molecules with the polar heads was responsible for the driving force in the interaction of oppositively charged anions. The paper deals with some alternative adsorption process for nutrients removal and Sr2+cation-exchange examined at the laboratory scale. The breakthrough curves for adsorption and ion-exchange process were plotted, under different conditions using the normalized effluent concentration (C/C0) versus time or bed volumes (BV). Optimization studies indicated that the lower flow rate exhibited the better performance.

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Low Cost Strategy for Removal of Fe3+, Cr3+ and Cu2+ Ions from Drinking Water of Chirang District, Assam

Thakuria M.N. and Talukdar A. K.

Drinking water samples of 27 sources consisting of ring wells, Tara pumps, tube wells and deep tube wells covering the Chirang District of Assam were collected and analyzed by standard methods. Some solutions with concentration of 10 and 20 times the highest field concentration were prepared and analyzed by Atomic Adsorption Spectrophotometer before and after passing through different adsorbents to investigate the extents of adsorption of Fe3+, Cr3+ and Cu2+ ions in the water samples. Amongst the adsorbents studied FER (Y-zeolite) was found to be the best while alumina had showed the minimum adsorption capacity towards Fe3+ ions from aqueous solutions in single elution. Two easily available materials, bark of Terminalia arjuna tree and rice husk had showed impressive adsorption character towards Fe3+ ions from 10×HFC solution. Carbon with a moderate Fe3+ ions adsorption capacity from iron contaminated water may act as one of the iron removers from drinking water. In case of Cr3+ ions FER(Y-zeolite) was found to be the best adsorbent, while FER(Y-zeolite) and bark of Terminalia arjuna tree had showed the excellent result for removal of Cu2+ ions from copper contaminated water.

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Mini Review: Modified Cyclodextrins as Molecular Sensors

Khalafi Lida

In this paper application of some functionaliz cyclodextrins with ability of molecular recognition are described. Combination of size selectivity in cyclodextrins with some selective analytical response produces a molecular sensor for selective chemical, pharmaceutical and environmental analysis.

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