Research Journal of Chemistry and Environment

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Esterification of lauric acid with methanol using sulfonated Starbons

Mena-Durán Cinthia J. and Macquarrie Duncan J.

Esterification of lauric acid with methanol is carried out using sulfonated Starbons®. These carbonaceous materials were shown to be more efficient than commercial sulfated zirconia and sulfonated Norit®. Microwave-assisted synthesis reduced reaction times from 12 hours in conventional heating to 30 minutes using microwave irradiation with conversions over 80 %. Mesoporosity of the materials and sulfur loading seem to be the keys to high conversions.

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Regeneration of Strontium loaded Ion exchange resin

Kumar Ratnesh, Narayanan R. Sathiya and Seshadri K. S.

The basic philosophies of radioactive waste management are delay and decay, dilute and dispersal and concentrate and containment. In addition to these, the recent option for waste management is recycle and reuse which arose due to the existence of precious elements available in the waste stream which when picked up judiciously can be put to use for their applications. The spent resins generated in the nuclear reactor were considered as waste and were subjected to disposal before thinking about the pickup of precious elements it contained. It contained essentially cesium, strontium, cobalt etc. with active loading to the extent of 0.1Ci /m3 and surface dose of the order 5 R. It is necessary to convert the spent resins into innocuous, non-leachable form. An attempt has been made to convert the simulated spent resin into multivalent ionic form in batch as well as in column studies to use the regenerated resin for uptake of radioactivity and minerals. Conditions favoring highest percentage exchange were attempted by using regenerant of higher concentration and smaller solid to solution ratio in the batch studies and optimized flow rate in the column studies to regenerate completely the active resin into inactive form.

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Kinetics of Chromium Biosorption onto Codium tomentosum

Suresh Babu P. and Anandaraj B.

Codium tomentosum, a marine macroalgae was reported earlier as effective removal agent of hexavalent chromium from the synthetic aqueous solution. Batch experiments were conducted at room temperature for 60 min to determine the reaction kinetics using around 600 microns sized particle of native Codium biomass at optimum pH of 2 with initial concentration of 50mg/L. The adsorbent dose was taken as 1g/L and the agitation was maintained at 150RPM. The adsorption equilibrium data was analyzed using various kinetic models like Lagergren’s Pseudo first order kinetics model, Ho and McKay’s Pseudo Second order kinetics model, Elovich Kinetics and Weber and Morris Intraparticle diffusion model. The experimental data correlates well with pseudo second order model than pseudo first order model. Elovich kinetic model defines the multi-layer adsorption kinetics and Weber and Morris Intra particle diffusion clearly depicts that the reaction mechanism follows 2 step rate processes and concludes that the reaction was multi linear. Native Codium biomass showed its potential as low cost biosorbent as reported earlier.

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Rigid Polyurethane Foam from grape seed Oil

Díaz-Medino A., Pérez A., Rodríguez J. F., De Lucas A. and Carmona M.

Highly unsaturated vegetable oils are inexpensive, accessible, produced in large scale and considered as a renewable resource. In this way, these materials could be useful as an alternative to the petrochemical raw materials. Grape seed oil with a high content of unsaturated triglycerides was transformed to a renewablepolyol having a molecular weight of 1800 gmol-1and a hydroxyl number of 80 mg KOH g-1. The vegetable oil was first epoxidized by using peroxiacetic acid reaching a yield of 70% to oxirane ring from the double bonds. The oxirane ring opening was accomplished by using glycerol (a by-product of biodiesel production) and a rigid polyurethane foam (RPU foam) was synthesized from the obtained polyol. Besides, a new method of organic phase purification was proposed using a strongly basic ion exchange resin (Amberlite IRA-402), obtaining a product with an acid value of 0.06 mg KOH g-1. Finally, the synthesized RPU foam exhibited a density of 68kgm-3 and a reduced compressive strength of 2.94MPag-1cm3 that satisfies the building normative. These values are similar to those reported in literature for RPU foams from commercial polyols.

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Effects of metal ions (Mg2+, Ca2+, Cd2+ and Zn2+) on ATP hydrolysis

Dong Dandan, Zeng Jinfeng, Huang Fang and Ma Yanqing

The interaction and the catalytic influence of the combined effects of metal ions (M: Mg2+, Ca2+, Cd2+ and Zn2+) and N-4-tosyl-L-arginine methyl ester hydrochloride (TAME) on the hydrolysis of ATP were examined using 1H and 31P NMR spectra. In the M-ATP-TAME ternary systems, the ATP interacts with the metal ions and TAME via β, γ-phosphate groups and adenine ring by electrostatic, cation-π and π-π stacking interaction. The preliminary study on the hydrolysis of ATP catalyzed by metal ions and TAME followed by 31P NMR spectroscopy shows that M-TAME can accelerate the ATP hydrolysis. The rate constant of ATP hydrolysis in the M-TAME-ATP ternary systems increased in the order of Zn2+ > Ca2+ > Cd2+ > Mg2+ respectively. This different catalytic behaviour was discussed in terms of the corresponding metal ion properties. At the same time, a reasonable mechanism has been proposed that ATP hydrolysis catalyzed by M-TAME occurs through an addition-elimination reaction sequence.

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Recovery of Metal Ions from Spent Lithium Ion Batteries (LIBs) using Sodium Salts of D2EHPA or P507: Performance Evaluation and Life Cycle Assessment

Shu-Hui Hung, Cheng-Fang Lin, Pen-Chi Chiang, Teh-Hua Tsai and Chen-Yu Peng

In this study, solvent extraction of Li, Co, Mn and Ni from spent Lithium Ion Batteries (LIBs) was carried out using sodium - di (2-ethylhexyl) phosphoric acid (Na-D2EHPA) and mono-2-ethylhexyl ester (Na-P507) dissolved in kerosene. Both the D2EHPA and P507 extractants were saponified by NaOH solution before it was used and the kerosene was used as the diluent. The concentrations of Li, Co, Mn and Ni ions were measured with an atomic absorption spectrophotometer (AAS). The percentage extraction for the metal ions including Li, Co, Mn and Ni was increased with increasing equilibrium pH. In addition, Mn was preferentially extracted over Li, Co and Ni with the extractants and D2EHPA was found to be the most suitable extractant for separation where the maximized separation factor was operated under an O/A ratio of 1:1 maximized with 1.0 M D2EHPA at an equilibrium pH value of 3.5. Furthermore, the environmental impacts using mid-point criteria including climate change (GWP500), freshwater ecotoxicity (FETPinf), freshwater eutrophication (FEP), human toxicity (HTPinf), marine ecotoxicity (METPinf), marine eutrophication (MEP), particulate matter formation (PMFP), photochem. oxidant form. (POFP), terrestrial acidification (TAP500), terrestrial ecotoxicity (TETPinf) and water depletion (WDP) for LIBs extraction process of Li were assessed by LCA.

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Chemical Speciation of Trace Elements in an Urban River System-Baghdad/Iraq

Hamad Samera H., Schauer James J. and Shafer Martin M.

Chemical speciation of a large group (23) of elements in the Tigris River within the urban environment of Baghdad city was studied. Chelex-100 and Diethylaminoethyl (DEAE) resin separation techniques followed by Magnetic Sector Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) analysis were applied to determine the labile and ionic fractions of filtrate elements in the river waters. Six samples from the Tigris River within Baghdad borders and one sample site from a major tributary of the Tigris (Diyala River) were collected in July-2011. Three groups of elements have been identified from the results of both separation techniques: (1) elements that exhibited high affinity either towards Chelex or DEAE with no apparent change in speciation. This group was sub-classified into: (a) elements where speciation results were consistent with the published literature (e.g. Mo) and (b) elements with only very limited reported speciation data in aquatic systems (e.g. Eu); (2) elements with observed changes in the speciation (e.g. Cr). Trends in the measured speciation of group 2 elements were examined in the context of major geochemical variables (including pH, TSS, major elements concentrations, Specific Conductance and Dissolved Organic Carbon). High T.S.S at specific sites has impacted some metals speciation (such as Sb) while high DOC concentrations have transported some metals (e.g. Pb) from the negative Chelex-effective sites to the positive DEAE-active sites. Information from this study may help in supporting efforts to predict the lability, bioavailability and toxicity of elements in aquatic system.

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Investigation of Heavy Metals Content in Medicinal Plants Sempervivum armenum Boiss. and Huet subsp. armenum (Crassulaceae) from Erzurum, Turkey

Şengül Köseoğlu Meryem

In this study heavy metals such as Fe, Zn, Mn, Ni, Pb, Cu and Cd were investigated in medicinally plants Sempervivum armenum Boiss. and Huet subsp. armenum as well as in the soil grown by using ICP-OES. The purpose of current study was to standardize indigenous medicinal plants for heavy metals contamination. The plant and soil samples were collected from their natural habitat at different locations in 2011-2012. The whole plant materials were found to contain all heavy metals except Pb. Among all heavy metals Fe was found to be at the highest level 379,716-548,626mg/kg followed by Mn 76,150-244,74mg/kg and Zn 35,315-80,150mg/kg while the rest of metals were at low concentration in plant parts. The obtained data were compared with the respective values recommended by the Polish standards. Simple correlation between heavy metal contents was tested on a significance level of p<0,01 with IBM SPSS Statistic 20. Our findings show that soils and plant parts were highly positive correlated. The present study considering these plants was found to be a reliable biomonitor for Fe, Mn, Zn in heavy metal polluted areas. Our results suggest that this medicinal uses should be collected from areas not contaminated with heavy metals.

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Spectral Investigation of Ruthenium (III) catalyzed Oxidation of Lactose by Potassium Permangnate in Acidic Medium

Kumar Ashish, Bashir Sumayah and Gani Zakir

The kinetics of Ruthenium (III) catalyzed oxidation of lactose by potassium permangnate in acidic medium has been studied spectrophotometrically in present investigation. First order kinetics with respect to variation in KMnO4 concentration is observed. The order of reaction with respect to substrate is zero but with respect to Ru(III) is one in this reaction. Increase in [H+] shows positive effect while increase in [Cl-] shows no effect. The active species of ruthenium (III) is understood as [Ru(H2O)4]+ . The reaction constants involved in the different steps of mechanism are calculated. Activation parameters with respect to the slow step of the mechanism are computed and discussed and thermodynamic quantities are also calculated.

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Continuous Fixed Bed Adsorption of Direct Red 28 by Walnut Wood Shavings: An Experimental and Modeling Study

Ertugay Nese and Malkoc Emine

Walnut wood shavings used in experiments is an industrial waste which is relatively abundant and inexpensive material that has been extensively investigated as adsorbents for removing contaminants from wastewater. In this study, the walnut wood shavings was tested for its ability to remove Direct Red 28 from aqueous solution by column experiments. All experiments were conducted fixed-bed columns. Experiments were carried out as a function of liquid flow rate, initial dye concentration and bed height. The total adsorbed quantities and equilibrium uptakes of dye related to the effluent volumes were determined by evaluating the breakthrough curves obtained at different flow rates, different inlet dye concentrations and different bed height. The adsorption capacity was increased with increasing bed height but decreased with increasing the inlet dye concentration and flow rate. The column sorption process was found to perform better at lower inlet dye concentration, lower flow rate and higher bed depth. Column performance has been modeled with Adams–Bohart, Yoon-Nelson, Thomas and BDST models. The results obtained from the mathematical model were in good agreement with the experimental datas which proved the success of the model in predicting the process.

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Synthetic Routes for Synthesis of Salicylaldiminate Derivatives of Group ‘4’ Metals [Titanium (IV) and Zirconium (IV)]

Dubey Raj Kumar and Singh Avadhesh Pratap

For synthesis of salicylaldiminate derivatives of group ‘4’ metals, a variety of synthetic routes using metal chlorides, metal isopropoxides and metal amines as starting materials have been employed and these are illustrated by equations and schemes in the present review article. Along with various synthetic routes of mixed ligand complexes of group ‘4’ elements some physical and spectroscopic properties have been discussed. Single crystal X-ray structures and application of complexes of group ‘4’ metals have also been incorporated in the present review.

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Heavy Metals in the Indian Atmosphere: A Review

Lakshmi Narayana Suvarapu, Young-Kyo Seo and Sung-Ok Baek

This study reviews the air quality in Indian metropolitan cities in terms of the heavy metal concentrations. Most Western countries were industrialized in the 19th century and/or early 20th century. On the other hand, in Asia, countries, such as India and China, were industrialized in the latter years of the 20th century. Western countries were more aware about air pollution than Asian countries. They implemented environmental friendly policies, such as the Euro standards, to control the air pollutants in their countries. Asian countries are further away from implementing such standards to control the air pollution than the Western countries. India is the second most populous country in the world with more than 1.2 billion people. This huge population and industrialization makes air pollution a challenging task for environmental researchers in India. A review of the status of heavy metal concentrations reported in Indian cities since 2000 is necessary to provide a clear picture of the ambient air quality in Indian cities with respect to the heavy metal content in ambient air. The monitoring of heavy metals is attracting considerable attention from environmental researchers because of the inclusion of heavy metals such as chromium and arsenic as group 1 carcinogens by the International Agency for Research on Cancer (IARC). This paper presents the sources, toxicity, biological importance and ambient air concentrations of heavy metals in several Indian cities reported since 2000.

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