Indian Journal of Chemical Technology

 

ISSN: 0971-457X

 

CODEN:ICHTEU

Volume 10

Number 1

January 2003

                                                                                              

                                                                                                                                          

 

 

 

CONTENTS

 

Research Articles

 

Conductometric and ultrasonic studies on ion-solvent interaction of K+ of KCNS in water + methanol/ethanol mixtures

7

J Ishwara Bhat & H R Shiva Kumar

 

 

 

Electrodeposition of Al-Ti alloys from aluminum chloride-N-(n butyl)pyridinium chloride room temperature molten salt

14

M R Ali, A Nishikata & T Tsuru

 

 

 

Molecular interactions in binary liquid mixtures of o-xylene with 1-alkanols at 303.15 K

21

C L Prabhavathi, K Sivakumar, P Venkateswarlu & G K Raman

 

 

 

Steady state rheology of PP/PET blends

27

T Kitano, Ajay Naik, S A R Hashmi, S R Vashishtha & Navin Chand

 

 

 

Graft polymerization of ethyl methacrylate onto guar gum using ceric ion/dextrose redox pair

38

P Chowdhury, S Samui, T Kundu, B Saha & A K Ghosh

 

 

 

Metal(IV) tungstates as solid acid catalysts for the synthesis of phthalate diester-dioctyl phthalte (DOP)

44

Alpana Parikh & Uma Chudasama

 

 

 

The influence of water in the synthesis of AlPO4-5 and of zeolite Ω

48

C I Round, M M N Gibbons, J J Cox & C D Williams

 

 

 

Decolourisation of industrial wastewaters of textile dying industry by photocatalysis

53

S Kanmani & K Thanasekaran

 

 

 

Pressure mediated reduction of aromatic nitro compounds with hydrazine hydrate

60

Hari Sankar Kakati & Dibakar Chandra Deka

 

 

 

Adsorption studies of lead ions on γ-Fe2O3-thiourea complex composite

63

Arunkumar Lagashetty, N N Mallikarjuna & A Venkataraman

 

 

 

Optimisation of GFAAS technique for beryllium determination in environmental samples

67

D D Thorat, T N Mahadevan & D K Ghosh

 

 

 

Comparative studies on adsorptive removal of chromium from contaminated water using different adsorbents

72

Ajay Meena & Chitra Rajagopal

 

 

 

TLC studies and separation of heavy metal cations on soil amended silica gel layers developed with surfactant-mediated solvent systems

79

Ali Mohammad & Nahed Jabeen

 

 

 

Removal of arsenic from water by coagulation treatment using iron and magnesium salt

87

B Ghosh, M C Das, A K Gangopadhyay, T B Das, K Singh, S Lal, S Mitra, S H Ansari, T K Goswami, S K Chakraborty & N N Banerjee

 

 

 

Notes

 

A simple sensitive spectrophotometric method for determination of dichlorvos in environmental samples

96

Anupama Asthana, Ajai Pillai & V K Gupta

 

 

 

Educator

 

Sodium carbonate-From natural resources to Leblanc and back

99

Jaime Wisniak

 

 

 


 

 

 

 

Indian Journal of Chemical Technology

Vol. 10, January 2003, pp. 7-13

 

Conductometric and ultrasonic studies on ion-solvent interaction of K+ of KCNS in water + methanol/ethanol mixtures

J Ishwara Bhat & H R Shiva Kumar

 The results of the ion-solvent interaction of K+, potassium thiocyanate in water + methanol/ethanol and their various mixtures (v/v) at 288, 298, 308 and 313K, using conductivity principle are reported. The solvation number of cation was determined by ultrasonic and mobility methods. Conductivity data were analysed by three major conductivity models. Limiting molar conductance decreases sharply with increase in co-solvent concentration. Association constant, Walden product, corrected Stoke`s radius (r1) and activation energy (Ea) of rate process were calculated for all solvent compositions and temperatures. Measured viscosity and ultrasonic velocity were used to determine solvation number of potassium ion (K+) and is found to be maximum in methanol. The Born relations were used to compute thermodynamics of solvation. All these data were used to investigate the nature of ion-solvent interaction existing in the system under prevailing conditions.

  

 

Indian Journal of Chemical Technology

Vol. 10, January 2003, pp. 14-20

 

Electrodeposition of Al-Ti alloys from aluminum chloride-N-(n-butyl) pyridinium chloride room temperature molten salt

M R Ali, A Nishikata & T Tsuru

Electrodeposition of aluminum-titanium alloys has been carried out onto platinum and mild steel cathodes from 6.14:3.07:0.09 (mole ratio) AlCl3-BPC-TiCl4 molten bath by controlled-potential and pulse potential methods. High concentration of TiCl4 (>0.1 mol dm-3) interferes with the deposition processes of Al and Al-Ti alloys. The deposition of pure titanium from this electrolyte is difficult, but titanium is co-deposited with aluminum in the form of alloys. The morphologies of the electrodeposited layers have been investigated by X-ray diffractometer and scanning electron microscope. The cathodic current efficiency for the deposition of alloys is about 97%.

 

 

Indian Journal of Chemical Technology

Vol. 10, January 2003, pp. 21-26

 

 

Molecular interactions in binary liquid mixtures of o-xylene with
1-alkanols at 303.15 K

C L Prabhavathi, K Sivakumar, P Venkateswarlu & G K Raman

 

  Excess molar volumes (VE) and isentropic compressibilities (kS) for binary mixtures of o-xylene with 1-propanol,1-butanol and 1-pentanol have been measured at 303.15 K. Excess volume exhibits an inversion in sign in all the three binary mixtures. Further, deviation in isentropic compressibility (KS) from ideal behaviour was also calculated. KS values exhibits an inversion in sign for the binary mixture o-xylene + 1-propanol and the quantity is positive over the entire range of composition in the remaining two mixtures. The experimental sound velocity data have been analysed in terms of Free length theory (FLT) and Collision factor theory (CFT ). The measured data is explained on the basis of intermolecular interactions between unlike molecules.

 

 

Indian Journal of Chemical Technology

 Vol. 10, January 2003, pp. 27-37

 

Steady state rheology of PP /PET blends

T Kitano, Ajay Naik, S A R Hashmi, S R Vashishtha & Navin Chand

The objective of this study is to report the results of steady state viscoelastic properties in molten state investigated experimentally for PP/PET blends. They were prepared by the elastic extrusion method. The present paper discusses the influence of different types of PP, blending composition and effect of compatibilizer on steady state viscoelastic properties of PP/PET in molten state.

 

 

Indian Journal of Chemical Technology Vol. 10, January 2003, pp. 38-43

 

Graft polymerization of ethyl methacrylate onto guar gum using ceric ion/dextrose redox pair

  P Chowdhury, S Samui, T Kundu, B Saha & A K Ghosh

The grafting of ethyl methacrylate (EMA) onto guar gum (GG) was studied as a function of monomer and initiator concentration, time, pH, and temperature. The presence of dextrose improves the efficiency of ceric ion towards grafting. Acid hydrolysis and infrared spectroscopy were used for the confirmation of grafting. The degradability, thermal stability and physical properties of GG and a representative graft copolymer were evaluated. Based on reaction kinetics, a grafting mechanism has been suggested.

 

 

Indian Journal of Chemical Technology

ol. 10, January 2003, pp. 44-47

 

Metal(IV)tungstates as solid acid catalysts for the synthesis of phthalate diester- dioctyl phthalate (DOP)

Alpana Parikh & Uma Chudasama

The study involves synthesis and characterization of amorphous M(IV) tungstates [M (IV) = Sn, Ti or Zr] which are inorganic ion exchangers of the class of tetravalent metal acid (tma) salts. The presence of structural hydroxyl protons on such materials indicates good potential for Bronsted acid catalysis. The catalytic activity of the materials abbreviated as SnW, TiW and ZrW has been explored by synthesizing a phthalate diester-dioctyl phthalate (DOP).

 

 

Indian Journal of Chemical Technology

Vol. 10, January 2003, pp. 48-52

 

The influence of water in the synthesis of AlPO4-5 and of zeolite symbol 87 \f "Symbol"

C I Round, M M N Gibbons, J J Cox & C D Williams

The synthesis of the aluminophosphate AlPO4–5 was optimized with regard to water in the formulation and likewise the synthesis of zeolite W. Calculations from published data suggested that optimization occurred when the ions had only their primary hydration sheaths.

 

 

Indian Journal of Chemical Technology

Vol. 10, January 2003, pp. 53-59 

 

Decolourisation of industrial wastewaters of textile dyeing industry
by photocatalysis

S Kanmani & K Thanasekaran

  The feasibility of photocatalytic decolourisation of real textile dyeing rinse wastewaters (RWWs) collected from the low salt cotton textile dyeing industry was studied, using two grades of titanium dioxide (TiO2) under ultraviolet (UV) and solar light sources. The effects of pH in the range of 6 - 10, catalyst concentration in the range of 0.05 – 0.5 g/L for indoor UV studies and 0.25 – 2.0 g/L for outdoor solar studies and catalyst reuse for twenty cycles were studied on photocatalytic decolourisation of four batches of industrial RWWs. Since the RWWs contained more than one dye, their colour measurements were done at multiple wavelengths of 436, 525 and 620 nm. In order to compare the effect of the operating variables on rinse wastewaters, the reaction time at 436 nm was taken into consideration since the reaction time necessary was the maximum at 436 nm. It is concluded that the decolourisation of RWWs could be carried out at the natural pH itself. A catalyst concentration of 1 g/L was found to be necessary in solar studies, whereas only one tenth of 1 g/L was needed for UV studies. The titanium dioxides were found to maintain their photoactivity during reuse for 20 cycles.

 

 

Indian Journal of Chemical Technology

Vol. 10, January 2003, pp. 60-62

 

Pressure mediated reduction of aromatic nitro compounds with hydrazine hydrate

Hari Sankar Kakati & Dibakar Chandra Deka

Reduction of aromatic nitro compounds to primary amines has been carried out with hydrazine hydrate under moderate nitrogen pressure. Under optimized reaction conditions of 2.0 MPa of nitrogen pressure at 150oC nitrobenzene is reduced to aniline in 89.7% yield. Under identical reaction conditions reductions of several other aromatic nitro compounds to their amines have been achieved in moderate to high yield.

 

Indian Journal of Chemical Technology

Vol. 10, January 2003, pp. 63-66 

 

Adsorption studies of lead ions on g-Fe2O3-thiourea complex composite

Arunkumar Lagashetty, N N Mallikarjuna & A Venkataraman

Adsorption of lead ions in aqueous solution on g-Fe2O3-thiourea complex composite is reported. The adsorbent was characterised by X-ray diffraction (XRD), infrared (IR) and scanning electron micrograph (SEM) studies. The eluent was subjected to atomic absorption spectroscopy to determine the percentage of the adsorbed lead ions onto the complex composite. IR studies of the complex composite showed that the formation of hydrogen bond from the amine group of the thiourea to the surface hydroxyl groups, and lead ions adsorbed on adsorbent shows shift in frequencies and with appearance of some new peaks. SEM studies for pure g-Fe2O3 show particles in the range of 100-200 nm with varying shape and size. The adsorbent shows foam net like structure on the surface of the complex composite. Atomic absorption studies showed the decrease of lead ions to 50% after adsorption with the complex composite. Solution conductivity of the eluent is increased to double that of pure lead solution after adsorption. The potential use of g-Fe2O3-thiourea complex composite in adsorption study is explained.

 

 

Indian Journal of Chemical Technology

Vol. 10, January 2003, pp. 67-71 

 

Optimisation of GFAAS technique for beryllium determination
in environmental samples

D D Thorat, T N Mahadevan & D K Ghosh

 The instrumental and analytical procedures involved in the estimation of beryllium in ambient air particulates, surface deposited dust and soil samples by the GFAAS technique have been optimised. Air samples were analysed directly after acid digestion. Non-specific interferences induced by the presence of salts in deposited dust and soil matrices were overcome by the optimisation of ashing parameters with suitable chemical modifiers. Instrumental detection limit was found to be 0.05 ng Be/mL. The concentration levels of beryllium in ambient aerosols, deposited dust and soil samples in the study area were found to be in the range of 0.01-2.5 ng/m3, 1.6-3.0 µg/g and 1.42-2.75 µg/g respectively. The method was found to be equally applicable to fly ash samples.

 

Indian Journal of Chemical Technology

Vol. 10, January 2003, pp. 72-78

 

Comparative studies on adsorptive removal of chromium from contaminated  water using different adsorbents

Ajay Meena & Chitra Rajagopal

 Chromium, especially the hexavalent form, is toxic to humans. Industries like chrome plating, textile, electroplating discharge Cr(VI) in their effluents. Wastes containing chromium are environmentally persistent and toxic, and cannot be degraded or detoxified biologically. Various techniques developed for the removal of heavy metals include chemical precipitation, ion exchange and adsorption. Activated carbon adsorption systems though widely used are very expensive and the regeneration cost is also very high. Therefore, their use in wastewater treatment may not be economically feasible. There is, therefore, a need to identify and study adsorptive characteristics of low cost alternatives. The present investigation was, therefore, undertaken to select suitable locally and commercially available adsorbents such as activated alumina, ion exchange resin, with special attention to low cost adsorbents like saw dust, treated saw dust and sand, and to carry out a comparative study of their applicability to heavy metal removal. The results of these studies are presented in this paper.

 

Indian Journal of Chemical Technology

Vol. 10, January 2003, pp. 79-86

 

TLC studies and separation of heavy metal cations on soil amended silica gel layers developed with surfactant-mediated solvent systems

Ali Mohammad & Nahed Jabeen

Thin-layer chromatography (TLC) of ten heavy metal cations was performed on soil, silica gel and soil mixed with silica gel sorbent phases using aqueous solutions of cetyl trimethyl ammonium bromide (CTAB), sodium dodecyl sulphate (SDS), polyoxyethylene dodecyl ether (Brij-35) and iso-octylphenoxypolyethoxy ethanol (TX-100) surfactants with or without added urea, nitrate or chloride of ammonium and sodium phosphate as mobile phases. In all, twenty-nine stationary and twenty-five mobile phases were used in order to examine the mobility pattern and to find out the best TLC system for metal cations separation from their multicomponent mixtures on soil mixed with silica gel layers. The mobility of all cations was insignificant on pure soil layers irrespective of the nature of mobile phase used. Addition of silica gel into soil bed leads to the increase of mobility and facilitates the separation of metal cations. Amongst surfactant solutions, CTAB at concentration level of 0.5 M was found to be most effective, the analytical potentiality of which was further improved in the presence of urea. The TLC system comprising of silica gel plus 0.6 M urea (1:1, v/v) as mobile phase was found most favourable for achieving separations of metal ions from their multicomponent mixtures. A few such separations worth mentioning include, Fe3+-Cu2+-Ni2+-Hg2+, Zn2+-Cd2+-Hg2+, Ni2+-Cu2+-Fe3+, Zn2+-Fe3+-Ni2+-Hg2+, Pb2+-Cd2+-Hg2+ and Ni2+-Cu2+-Pb2+. RF values of metal ions on soil amended with alumina, kieselguhr, cellulose and fly ash layers have also been determined. Salting – in effect exhibited by certain metal ions like Cd2+, Ni2+ or Co2+, Ag+, Hg2+ has been reported. Effect on mobility of metal ions, by replacing urea with different fertilizers in the CTAB containing mobile phase has also been examined.

 

Indian Journal of Chemical Technology

Vol. 10, January 2003, pp. 87-95

 

Removal of arsenic from water by coagulation treatment
using iron and magnesium salt

B Ghosh, M C Das, A K Gangopadhyay, T B Das, K Singh, S Lal, S Mitra, S H Ansari,

T K Goswami, S K Chakraborty & N N Banerjee

Arsenic in ground water assumes a predicament of global dimension. Among the various methods of removal of arsenic from contaminated water, coagulation-filtration route has been examined in details covering effect of pH, coagulant type and its dose, and initial arsenic load in water. A set of batch experiments were conducted in the laboratory to investigate arsenic removal efficiency from spiked aqueous solution as well as a few ground water samples collected from the affected zone of West Bengal (India). The removal kinetics of aqueous arsenic spiked samples with iron/magnesium salt as coagulants were studied to assess the feasibility for the use in the arsenic removal in water treatment plant, and a plausible kinetic behaviour in their removal process has been discussed. A comparative performance efficiency for iron salt in contrast to magnesium salt as coagulant has been examined to establish the superiority of iron system. Increase in background ionic species such as ClŻ, NO3Żand SO2-4 in test solution with iron system have been performed in which ClŻ and NO3Ż ions showed no effect on the efficiency of arsenic removal, while pronounced lowering effect has been observed in case of SO2-4 ion. This investigation suggests that for community supply of arsenic free water, the proposed protocol-coagulation with iron salt and subsequent filtration hold promise.

 

 

Indian Journal of Chemical Technology

Vol. 10, January 2003, pp. 96-98

 

A simple sensitive spectrophotometric method for
determination of dichlorvos in environmental samples

Anupama Asthana, Ajai Pillai & V K Gupta

A sensitive method has been developed for spectrophotometric determination of an organophosphorous pesticide dichlorvos, also known as 2,2 dichlorovinyl methyl phosphate or dichlorophos. The method is based on hydrolysis of dichlorvos by sodium hydroxide to produce dichloroacetaldehyde, which on coupling with phloroglucinol in alkaline medium, gives orange colour. The orange dye shows absorption maxima at 475 nm and obeys Beer’s law in the range of 10 -100µg/25 mL (0.4 to 4 ppm) of solution. The molar absorptivity and Sandell’s sensitivity were found to be 4.53 ´ 104 l mol-1 cm-1 and 0.0048 µg cm-2 respectively. The method has been successfully applied for the determination of dichlorvos in water, agricultural soil and vegetables.

 

 

Indian Journal of Chemical Technology

Vol. 10, January 2003, pp. 99-112

 

 

Sodium carbonateľFrom natural resources to Leblanc and back

 Jaime Wisniak

The development of sodium carbonate as a major commodity is intimately attached to the chemical revolution that took place in the eighteenth and nineteenth century. Strong political and economical reasons led to the search of synthetic procedures to replace the natural sources of soda that were available by the seventeenth century. Eventually Nicolas Leblanc developed a synthetic process that used common salt as raw material. Implementation of Leblanc’s procedure led to such serious environmental problems, e.g., acid rain, that the first laws for environmental protection were enacted in England. Treatment of the obnoxious gaseous, liquid, and solid wastes of the process resulted in new processes for the manufacture of chlorine and sulphur. Leblanc’s process came to an end with the development of the Solvay process. Eventually, the discovery of huge fields of natural sodium carbonate in the U.S. led to the decline of the Solvay process.