Indian Journal of Chemical Technology

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VOLUME 17

NUMBER 2

MARCH 2010

CODEN: ICHTEU

 

ISSN: 0971-457X

CONTENTS

 

Papers

 

 

 

Corrosion inhibition of Al-Mg alloy by gentisic acid

89

      L Vrsalovic, M Kliskic, S Gudic & I Smoljko

 

 

 

Inhibition of corrosion of copper by 2,5-dimercapto-1,3,4-thiadiazole in

95

      3.5% NaCl solution

 

      M Yadav & Dipti Sharma

 

 

 

Performance of different organic coatings on steel substrate by accelerated

102

      and in atmospheric exposure tests

 

      Jayanta Kumar Saha, P K Mitra, S Paul & D D N Singh

 

 

 

Sonochemical degradation of p-chlorophenol in aqueous solution using

111

      hypervalent iron

 

      Praveena Juliya Dorathi R & K Palanivelu

 

 

 

Fluoride removal from water using crushed limestone

120

      Suresh K Nath & Robin K Dutta

 

 

 

Performance and stability study of vegetable oil based supported liquid

126

      membrane

 

      Mousumi Chakraborty, Dilip Dobaria & Parimal A Parikh

 

 

 

Study of bulk liquid membrane as a separation technique to recover acetic

133

      and propionic acids from dilute solutions

 

      A Kaur & D K Vohra

 

 

 

Synthesis of a biodegradable polyacrylonitrile/sodium silicate nanocomposite

139

      fire retardant

 

      Ramakanta Samal & Prafulla K Sahoo

 

 

 

Dissolution of copper from a primary chalcopyrite ore calcined with and

145

      without Fe2O3 in sulphuric acid solution

 

      Mustafa Gulfen & Ali Osman Aydin

 

 

Spectrophotometric determination of frusemide by its oxidation with ceric

150

      ammonium sulphate

 

      B Narayana & K Ashwini

 

 

 

Notes

 

 

 

Extraction chromatographic separation of molybdenum(VI) with high

154

      molecular weight liquid anion exchanger

 

      Sudarshan J Kokate, Amol A Gavande, Vittal K Vikhe, Haribhau R Aher

 

      & Shashikant R Kuchekar

 

 

 

Author Index

159

 

 

Keyword Index

160

 

 

Guidelines for Authors

161

 

 

 

 

 

 

 

 

Indian Journal of Chemical Technology

Vol. 17, March 2010, pp. 89-94

 

 

Corrosion inhibition of Al-Mg alloy by gentisic acid

L Vrsalović*, M Kliškić, S Gudić & I Smoljko

Department of Electrochemistry and Protection of Materials, Faculty of Chemistry and Technology,
University of Split, Teslina 10/V, 21000 Split, Croatia

Email: ladislav@ktf-split.hr

Received 29 June 2009; revised 19 October 2009

Gentisic acid was studied for possible use as an Al-2.5Mg alloy corrosion inhibitor in a 0.5 mol dm-3 NaCl solution. Investigations were performed on a rotating disc electrode in a quiescent solution at different electrode rotation rates and electrolyte temperatures. The results indicate that, the addition of gentisic acid inhibits corrosion of Al-2.5Mg alloy, and the inhibition efficiency increases with increasing inhibitor concentration but decreases with increasing electrode rotation rate and electrolyte temperature. The investigated compound acts as a cathodic-type inhibitor and the inhibition is ascribed to the adsorption of the inhibitor onto the electrode surface. The adsorptive behaviour of gentisic acid follows the Freundlich adsorption isotherm.

Keywords: Al-Mg alloy, Corrosion inhibition, Gentisic acid, Rotating disc electrode, Adsorption, Activation energy

 

 

Indian Journal of Chemical Technology

Vol. 17, March 2010, pp. 95-101

 

 

Inhibition of corrosion of copper by 2,5-dimercapto-1,3,4-thiadiazole
in 3.5% NaCl solution

M Yadav*& Dipti Sharma

Department of Applied Chemistry, Indian School of Mines University, Dhanbad 826 004, India
Email : yadav_drmahendra@yahoo.co.in

Received 24 March 2009; revised 7 December 2009

The inhibitor 2,5-dimercapto1,3,4-thiadiazole shows 94.48 percent inhibition efficiency in controlling corrosion of copper in 3.5%NaCl solution at pH 7.0. The mechanistic aspects of corrosion inhibition, based on the results obtained from the weight loss method, potentiostatic polarization study, AC-impedance study, UV-visible absorption study and surface study by FTIR, ESCA and SEM have been discussed. The inhibitor 2,5-dimercapto-1,3,4-thiadiazole appears to inhibit corrosion process through formation of protective film which was found to consist of Cu(I)-inhibitor complex, cuprous chloride, CuCl or complex ion or both and no oxide of copper on the surface.

Keywords: Copper, Corrosion inhibition, 2,5-Dimercapto-1,3,4-thiadiazole

 

 

Indian Journal of Chemical Technology

Vol. 17, March 2010, pp. 102-110

 

 

Performance of different organic coatings on steel substrate by accelerated and in atmospheric exposure tests

Jayanta Kumar Saha1*, P K Mitra2, S Paul2 & D D N Singh3

1Institute for Steel Development & Growth, Kolkata 700 019, India

2Metallurgical & Material Engineering, Jadavpur University, Kolkata 700 075, India

3National Metallurgical Laboratory, Jamshedpur 831 007, India

Email: jayantaksaha@gmail.com

Received 29 July 2009; revised 17 November 2009

Organic coatings act as a barrier to a corrosive solution and check the transfer of electrical charge from the corrosive solution. High performance organic paint systems were applied on plain carbon steel substrate with two different primers viz., epoxy Zn phosphate and epoxy Zn rich. Identical intermediate and top coats were applied on them having equal dry film thickness. Both uncontrolled long term testing and controlled laboratory testing were conducted to evaluate the performance of the coatings. Salt spray, and electrochemical impedance spectroscopy (EIS), were carried out on fresh coated panels whereas both EIS and DC polarisation studies were done on the panels withdrawn from field exposure racks using different electrolytes. Polarisation resistance, coating capacitance, water absorption, and corrosion potential were studied to understand the causes of deterioration and to have faster assessment of durability of these paint formulations. Corrosion products were characterised by Scanning Electron Microscope (SEM) through morphology and Raman spectra through phase identification. The performance of epoxy Zn phosphate base primer is very much comparable with epoxy Zn rich base primer. The findings were supported from the tests conducted on the panels exposed for two years under the industrial climatic conditions. The rust formed under the atmospheric condition is non protective lepodocrocite.

                Keywords: Primers, Organic coating, Atmospheric corrosion, EIS, SEM, Raman spectroscopy

 

 

Indian Journal of Chemical Technology

Vol. 17, March 2010, pp. 111-119

 

 

Sonochemical degradation of p-chlorophenol in aqueous solution using hypervalent iron

Praveena Juliya Dorathi R & K Palanivelu*

Centre for Environmental Studies, Anna University Chennai, Chennai 600 025, India

Email: kpvelu@annauniv.edu

Received 27 August 2009; revised 2 February 2010

Sonochemical degradation of p-chlorophenol (CP) by coupling a well-known environmental friendly oxidant – iron (VI) in the form of potassium ferrate, with the assistance of sonication (Sono ferrate) was experimented upon in this work. The efficiency of the method was monitored by the degradation and mineralization of p-chlorophenol. The relevant parameters namely pH and ferrate: CP ratio were optimized. The optimal pH and the ferrate: CP ratio for the sono ferrate method was found to be 8.0 and 3:1 at which the removal efficiency with respect to chemical oxygen demand was found to be 85.7% in 75 min and the mineralization efficiency (TOC removal) was 71.6%. It was observed that sono ferrate method was more effective than simple ferrate method. Hence it is recommended to use sono ferrate method as an effective, clean and green way of degrading CP.

Keywords: p-Chlorophenol, Degradation, Potassium ferrate, Sonication, Sono ferrate

 

 

 

 

 

Indian Journal of Chemical Technology

Vol.17, March 2010, pp. 120-125

 

 

Fluoride removal from water using crushed limestone

Suresh K Nath & Robin K Dutta*

Department of Chemical Sciences, Tezpur University, Napaam, Tezpur 784 028, India

Email: suresh@tezu.ernet.in, robind@tezu.ernet.in

Received 15 April 2009; revised 22 January 2010

An examination of defluoridation by industrial grade limestone indicated that a combination of precipitation and adsorption of fluoride can be more effective for defluoridation of water. Pre-acidified fluoride water using two edible acids, viz., acetic acid (AA) and citric acid (CA) have been used for treatment by crushed limestone of diameter 3-4 mm to precipitate fluoride as CaF2 in addition to adsorption of fluoride on limestone. The study has been carried out in batches by varying the acid concentration and contact time. Addition of the acids to the water before treatment with the crushed limestone in batch tests significantly improved the fluoride removal and this increased with the increase in the concentrations of the acids. The concentration of CA and AA required bringing down the fluoride concentration from 10 to 1.5 mg/L, are 0.05 M and 0.033 M, respectively, when the crushed limestone chips sample was used for the first time with contact time of 12 h. The acids are neutralized by limestone during the defluoridation process and the resulting final pH of the treated water was found to be in the ranges of 6.2 and 7.0 for CA and 5.7 and 7.0 for AA.

Keywords: Defluoridaton, Limestone, Calcite, Acetic acid, Citric acid

 

 

Indian Journal of Chemical Technology

Vol.17, March 2010, pp. 126-132

 

 

Performance and stability study of vegetable oil based
Supported Liquid Membrane

Mousumi Chakraborty*, Dilip Dobaria & Parimal A Parikh

Department of Chemical Engineering, S.V. National Institute of Technology, Surat 395 007, India

Email: mch@ched.svnit.ac.in

Received 25 March 2009; revised 5 October 2009

A study on Supported Liquid Membrane (SLM) system has been performed for removal and recovery of a textile dye Red 4G from the aqueous solution. Renewable, non toxic, natural vegetable oils as liquid membrane phase have been incorporated in Polypropylene(PP) supported teflon membrane. Membrane phase composition, pH of feed solution, acid/base concentration in the striping solution and initial dye concentrations are systematically investigated using vegetable oil based SLM during the extraction of dye. Stability study of SLM is carried out with ‘wet surface’ and ‘dry surface’ membranes. The Scanning electron microscope (SEM) combined with Energy dispersive X-ray (EDX) analysis of membranes after continuous operation shows that the membrane phases are retained within the membrane pores and only small losses of the membrane phase initially located on the surface are observed. These observations are in complete agreement with the membrane phase losses determined by mass balance.

Keywords: Supported liquid membrane, Vegetable oils, PP supported teflon membrane, Red 4G dye, SEM, EDX

 

 

 

 

Indian Journal of Chemical Technology

Vol. 17, March 2010, pp. 133-138

 

 

 

Study of bulk liquid membrane as a separation technique to recover acetic and propionic acids from dilute solutions

A Kaur* & D K Vohra

University Institute of Engineering and Technology,

Sector 25, Panjab University, Chandigarh 160 014, India
Email: anupreetz@yahoo.co.in

Received 14 May 2009; revised 1 December 2009

Liquid membranes incorporating potential chemical species can perform rapid and selective transport of a variety of guest species and that too being much energy efficient than other separation methods. Separation characteristics of a bulk liquid membrane were investigated to recover acetic acid and propionic acid from dilute aqueous solutions by reactive extraction process. The liquid membrane made up of trioctylamine as an extractant and toluene as an organic diluent was tested. The membrane was kept in contact with two aqueous phases namely acidic feed phase and alkaline strip phase. The parameters affecting the extraction of the acid including nature of the feed phase, sodium hydroxide concentration in the strip phase and concentration of trioctylamine in membrane phase were investigated. The membrane system was observed to have potential to extract both the acids which was confirmed with the increase in the percentage extraction and the mass-transfer coefficient with time. The set-up under investigation could extract about 40% of the acid in first five hours of operation under defined conditions. The set-up was found to be more favourable for propionic acid in comparison to acetic acid as the difference in extraction efficiency widens with the increase in the strength of the strip phase solution.

Keywords:   Bulk liquid membrane, Reactive extraction, Recovery of propionic acid, Acetic acid, TOA

 

 

Indian Journal of Chemical Technology

Vol. 17, March 2010, pp. 139-144

 

 

Synthesis of a biodegradable polyacrylonitrile/sodium silicate nanocomposite
fire retardant

Ramakanta Samal & Prafulla K Sahoo*

Department of Chemistry, Utkal University, Vani Vihar, Bhubaneswar 751 004, India

Email: psahoochemuu@satyam.net.in

Received 15 June 2009; revised 26 October 2009

Polyacrylonitrile (PAN)/Sodium silicate (SS) nanocomposite was synthesized via non-conventional emulsifier free emulsion method using an in situ developed transition metal complex Cu(II)/EDTA taking potassium monopersulfate (KMPS) as initiator, with a novel motive of converting hydrophobic homopolymer PAN into hydrophilic nanocomposite by the inclusion of SS to the homopolymer. The formation of the PAN/SS nanocomposite was confirmed by infrared spectra (IR). Furthermore, as evidenced by transmission electron microscopy (TEM), the composite so obtained was found to have nano scale structure. X-ray diffraction (XRD) was carried out suggesting that the silicate layers were exfoliated or intercalated during the polymerization process. An increase in the thermal stability for the developed nanocomposite was recorded by thermogravimetric analysis (TGA). The combustion behaviour has been evaluated using oxygen consumption cone calorimeter and the nanocomposite exhibited good fire retardancy. The PAN/SS nanocomposite was found to be biodegradable as tested by sludge water and further confirmed by scanning electron microscopy (SEM).

Keywords: Emulsifier-free emulsion, Nanocomposite, Fire retardant, Biodegradation

Synthesis of a biodegradable polyacrylonitrile/sodium silicate nanocomposite fire retardant

Ramakanta Samal & Prafulla K Sahoo*

Department of Chemistry, Utkal University, Vani Vihar, Bhubaneswar 751 004, India

Email: psahoochemuu@satyam.net.in

Received 15 June 2009; revised 26 October 2009

Polyacrylonitrile (PAN)/Sodium silicate (SS) nanocomposite was synthesized via non-conventional emulsifier free emulsion method using an in situ developed transition metal complex Cu(II)/EDTA taking potassium monopersulfate (KMPS) as initiator, with a novel motive of converting hydrophobic homopolymer PAN into hydrophilic nanocomposite by the inclusion of SS to the homopolymer. The formation of the PAN/SS nanocomposite was confirmed by infrared spectra (IR). Furthermore, as evidenced by transmission electron microscopy (TEM), the composite so obtained was found to have nano scale structure. X-ray diffraction (XRD) was carried out suggesting that the silicate layers were exfoliated or intercalated during the polymerization process. An increase in the thermal stability for the developed nanocomposite was recorded by thermogravimetric analysis (TGA). The combustion behaviour has been evaluated using oxygen consumption cone calorimeter and the nanocomposite exhibited good fire retardancy. The PAN/SS nanocomposite was found to be biodegradable as tested by sludge water and further confirmed by scanning electron microscopy (SEM).

Keywords: Emulsifier-free emulsion, Nanocomposite, Fire retardant, Biodegradation

 

 

Indian Journal of Chemical Technology

Vol. 17, March 2010, pp. 145-149

 

Dissolution of copper from a primary chalcopyrite ore calcined with and without Fe2O3 in sulphuric acid solution

Mustafa Gülfen* & Ali Osman Aydın

Department of Chemistry, Faculty of Arts & Sciences, Sakarya University
TR-54187, Esentepe Campus, Sakarya – Turkey

Email: mgulfen@sakarya.edu.tr

Received 27 May 2009; revised 30 October 2009

Dissolution of copper from a primary chalcopyrite ore supplied from Damar mine area in Murgul-Artvin, Turkey, has been investigated in sulphuric acid solution after the calcination with and without Fe2O3. The chalcopyrite with and without Fe2O3 were performed by thermogravimetric (TG) analysis, and the calcined chalcopyrite samples were characterized by
X-ray diffraction (XRD). In the leaching experiments, the effects of calcination temperature, sulphuric acid concentration, solid/liquid ratio, agitation rate, particle size and dissolution temperature and time on copper dissolution were examined. It was found that Fe2O3 addition contributed to sulphation during the calcination and then copper dissolution.

Keywords: Chalcopyrite, Iron(III) oxide, Sulphation, Dissolution, Sulphuric acid

 

 

 

 

 

Indian Journal of Chemical Technology

Vol. 17, March 2010, pp. 150-153

 

 

Spectrophotometric determination of frusemide by its oxidation with
ceric ammonium sulphate

B Narayana* & K Ashwini

Department of Post Graduate Studies and Research in Chemistry, Mangalore University, Mangalagangothri 574 199, India

Email: nbadiadka@yahoo.co.uk

Received 3 August 2009; revised 7 December 2009

A simple and sensitive spectrophotometric method is described for the determination of frusemide (FRU). The method is based on the reaction of FRU with measured excess of ceric ammonium sulphate (CAS) followed by the determination of unreacted oxidant using xylene cyanol FF (XC) (Method A) and safranin O (SAF) (Method B). The reaction mixture exhibited maximum absorbance at 612 nm (Method A) and 526 nm (Method B). The calibration graph was linear from 20.00 to 30.00 µg mL-1 and 6.00 to 16.00 µg mL-1 for methods A and B respectively. The apparent molar absorptivity and Sandell’s sensitivity for method A and B were calculated to be 1.160×104 L mol-1cm-1, 2.025´104 L mol-1 cm-1 and
2.82×10-3 µg cm-2, 0.0163 µg cm-2 respectively. The method has been applied for the determination of frusemide in pure and dosage forms.

                   Keywords: Frusemide determination, Oxidation, Ceric ammonium sulphate, Spectrophotometry

 

 

Indian Journal of Chemical Technology

Vol. 17, March 2010, pp. 154-157

 

 

Extraction chromatographic separation of molybdenum(VI) with high molecular weight liquid anion exchanger

Sudarshan J Kokate, Amol A Gavande, Vittal K Vikhe, Haribhau R Aher & Shashikant R Kuchekar*

P. G. Department of Analytical Chemistry, P. V. P. College, Pravaranagar,

At/Po – Loni (Kd), Tal. Rahata, Dist. Ahmednagar, 413 713, India

Email: shashi17@gmail.com

Received 29 June 2009; revised 24 November 2009

New and innovative separation method was developed for extraction of molybdenum(VI) from aqueous chloride media with N-n-octylaniline (liquid anion exchanger) coated on silica gel. Molybdenum(VI) was quantitatively extracted from 1.25 M HCl, eluted with distilled water and determined by spectrophotometric method. Different parameters viz. effect of HCl concentration, N-n-octylaniline concentration and flow rate of mobile phase were studied. The method was applied for separation of molybdenum(VI) from binary mixtures and synthetic mixtures corresponding to alloys and fertilizer samples.

Keywords: Extraction chromatography, Molybdenum(VI)  separation, N-n-Octylaniline, Liquid ion exchanger