Indian Journal of Chemical Technology

http://www.niscair.res.in

Total visitors:2,752 since 10-05-07

VOLUME 14

NUMBER 3

MAY 2007

CODE(S)N:ICHTEU

 

ISSN:0971-457X

CONTENTS

Papers

 

Biodegradation of lactic acid and polyethylene glycol based polyester urethanes

221

IPC Code(s): C08G63/00, C12P1/00

 

Suparna Sarkar & Basudam Adhikari

 

Bio-alkaper and peroxide-alkali delignifications of solid waste of Cymbopogon martini with Phanerochaete chrysosporium

229

IPC Code(s): G01N, C11B9/00

 

Dharm Dutt, A P Garg, C H Tyagi & A K Upadhyay

 

Electrocoagulation: A cleaner method for treatment of Cr(VI) from electroplating industrial effluents

240

IPC Code(s): C25D3/04

 

Daniel Reddithota, Anjaneyulu Yerramilli & Reddithota J Krupadam

 

Electrodeposition and compositional behavior of Zn-Ni alloy

246

IPC Code(s): C25D3/56

 

V Thangaraj & A Chitharanjan Hegde

 

Experimental study of hydrodynamic and bubble size distributions in electroflotation process

253

IPC Code(s): C25D, G01N30/00

 

L Ben Mansour, S Chalbi & I Kesentini

 

Role of momentum exchange coefficient in circulating fluidized- bed

258

IPC Code(s): B01J8/24

 

Shriram Prasad & Alok Gautam

 

Dissolution kinetics of iron and aluminium from red mud in sulphuric acid solution

263

IPC Code(s): C22B3/00

 

Deger Uzun & Mustafa Gülfen

 

Solvent extraction of Cu(II) by purified cyanex 272

269

IPC Code(s): B01D11/00, C22B3/26

 

R K Biswas & H P Singha

 

Adsorption of As(V) from aqueous solution by chemically doped coir pith carbon

276

IPC Code(s): B01D17/00: 15/00

 

R Selvakumar, S Kavitha & K Swaminathan

 

An integrated investigation of volatile organic compounds emission in the atmosphere from refinery and its off-site facilities

283

IPC Code(s): C10G17/00

 

G H Pandya, V K Kondawar & A G Gavane

 

Esterification of salicylic acid with methanol/dimethyl carbonate over anion- modified metal oxides

292

IPC Code(s): C07C67/00

 

Joyce D’Souza & N Nagaraju

 

Hydration of calcined bentonite Portland blended cement pastes

301

IPC Code(s): C04B7/02

 

H H M Darweesh & Z A Nagieb

 

Indirect complexometric determination of thallium(III) in its alloys and complexes using thiomalic acid as a selective releasing agent

308

IPC Code(s): C01G15/00, C01B6/06

 

P Parameshwara, J Karthikeyan, A Nityananda Shetty & Prakash Shetty

 

Notes

 

Quantification of an antiviral drug(stavudine) by three procedures based on redox and complex formation using N-bromosuccinimide

313

IPC Code(s): A61K

 

K Basavaiah, V Rama Krishna & U R Anil Kumar

 

Relationship of z-tensile strength with in-plane strength properties of paper

317

IPC Code(s): D21H15/00

 

S P Singh

 

Sulphonated lignin based screen ink formulations

321

IPC Code(s): C09D11/00, C08G

 

S A Mandavgane, B B Gogte & D Subramanian

 

Author Index

325

Keyword Index

326

Guidelines for Authors

327

 

 

 

 

 

 

 

 

 

 

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 221-228

Biodegradation of lactic acid and polyethylene glycol based polyester urethanes

Suparna Sarkar & Basudam Adhikari*

A novel polyester urethane based on lactic acid and polyethylene glycol 400 (PEG400) was synthesized. The biodegradation of the polyester urethane under soil burial condition and by cultured bacteria (Pseudomonas aeruginosa) at different temperatures (5, 15, 37° C) was studied. The biodegradation was assessed from the weight loss, tensile strength and ultimate elongation as well as chemical changes by FTIR spectroscopy and visual changes by optical and scanning electron microscopy. After 30 days of exposure of the polyester urethane films to cultured Pseudomonas aeruginosa around 33-36% degradation in terms of weight loss was observed. Under soil burial degradation the samples have shown 62% weight loss in 180 days but there is around 98 to 99% loss in tensile strength and elongation at break.

Keywords: Polyester urethane, Biodegradation, Soil, Bacteria, Tensile strength, Elongation at break

IPC Code (s): C08G63/00, C12P1/00

 

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 229-239

Bio-alkaper and peroxide-alkali delignifications of solid waste of Cymbopogon martini with Phanerochaete chrysosporium

Dharm Dutt*, A P Garg, C H Tyagi & A K Upadhyay

Palma rosa grass (Cymbopogon martini) is cultivated for palma rosa oil. The solid waste of C. martini left after steam distillation creates environmental problems. This hitherto unexploited source of fibers obtained from solid waste of C. martini can successfully be used for the production of chemical grade pulp. C. martini has low lignin and more open and looser structure, which makes it suitable for bio-pulping, which is then followed by alkaper and peroxide-alkali delignification processes. The present study reveals that steam distillation of C. martini removes oil ducts, which makes the solid waste more open and looser compared to untreated C. martini and enables the solid waste of C. martini more suitable for bio-alkaper and peroxide-alkali delignification processes by abating the mass transfer problem of HOO, OH, and O2, which is far less than C. martini without distillation. Bio-pulping process significantly decreases the energy requirement in paper industry, which has beneficial effect on the over all energy input. Since the bio-pulping process is highly specific in action and requires milder cooking conditions. The aim of bio-pulping of solid waste of C. martini is to reduce the energy requirement in the form of cooking chemicals and to improve paper strength with Phanerocheate chrysosporium, which is then followed by the non-sulphur pulping process— bio-alkaper and peroxide-alkali delignification processes.

Keywords: Cymbopogon martini, Steam distillation, Phanerochaete chrysosporium, Bio-alkaper and peroxide-alkali, Delignification

IPC Code(s): G01N, C11B9/00

 

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 240-245

Electrocoagulation: A cleaner method for treatment of Cr(VI)
from electroplating industrial effluents

Daniel Reddithota, Anjaneyulu Yerramilli & Reddithota J Krupadam *

Chromium contamination in waters are highly toxic even in very low concentrations and need to be completely removed from the effluents before they are discharged into a stream, sewer or on land. Electroplating industry is one of the industrial sectors producing chromium bearing wastewaters, mostly originating from chromium plating, anodizing, electroplating solutions and dip solutions like passivating dips, bright dips, etc. Chromium concentration in the effluents varies from 3 to 50 mg/L depending upon the care with which the plating operations are carried out. The results of this study have shown the applicability of electrocoagulation as a clean method for treatment of Cr(VI) containing wastewaters. The optimum removal of Cr(VI) was attained between pH 4-8. Increase in current density enhances the removal rate and the quickest treatment with an effective reduction of Cr(VI) concentrations was achieved below permissible level within 20 min. Iron electrodes were found to be more efficient in removing chromium in comparison to the aluminum and hydrid Al/Fe electrodes. This may be due to the formation of stable Fe-Cr complex which is more stable than Al-Cr complexes. On the other hand, 1 kg of Cr(VI) removal produces only 2,8 kg of sludge against 36 kg of sludge generated from iron sulphate precipitation method. The rate of removal is faster in comparison to the adsorption on activated carbon which is one of the most important requirement for practical application of this treatment method.

Keywords: Electrocoagulation, Electroplating effluents, Chromium (VI) treatment

IPC Code(s): C25D3/04

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 246-252

Electrodeposition and compositional behaviour of Zn-Ni alloy

V Thangaraj & A Chitharanjan Hegde*

This paper discusses the optimization of an electroplating bath for smooth and uniform deposition of zinc-nickel alloy on mild steel. Electroplating has been carried out in a chloride bath using glycine and gelatin as additives. The effect of bath conditions and operating parameters on chemical composition, micro-hardness and appearance of the deposit have been studied and discussed. The experimental results reveal that a bright Zn-Ni alloy having about 13.6 %Ni is showing good performance against corrosion. The corrosion resistance of the deposit is found to be characteristic of its %Ni content, and is improved drastically after chrome passivation. The bath follows anomalous codeposition with preferential deposition of Zn over the entire current density range used for the study. The increase of %Ni in the deposit with current density is due to the depletion of more readily depositable Zn2+ ions at the cathode. No transition current density, at which the codeposition behaviour changed from the anomalous to normal type, was observed during the study. The increase of %Ni in the deposit at high current density (c.d.) is attributed to high ratio of Ni2+/Zn2+ in the bath. The effect of temperature on the plating process showed that codeposition of metals on the cathode is diffusion controlled.

Keywords: Zn-Ni alloy, Chloride bath, Glycine, Gelatin

IPC Code (s): C25D3/56

 

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 253-257

Experimental study of hydrodynamic and bubble size distributions
in electroflotation process

L Ben Mansour*, S Chalbi & I Kesentini

The objective of this contribution is the experimental study of the hydrodynamic and the bubble size distributions in the electroflotation process. The influence of some operating conditions such as current density and physical properties of liquid phase on some hydrodynamic parameters and the bubble size distribution are discussed. The effects of the current density, viscosity and surface tension of the liquid phase on the gas hold up, the bubble rise velocity, the average bubble diameter and the bubble size distributions are experimentally investigated. Bubbles tend to become smaller with decreasing surface tension, current density and viscosity. Gas hold up tends to increase with increasing current density and decreasing viscosity. The bubble rise velocity exhibits the same behaviour as the gas hold up and so it increases with the increasing current density and decreases with increasing viscosity. Bubble size distribution depends only on the current density, and the wide range of bubble sizes increases with increasing current density. For such systems most of the hydrodynamic parameters depend on the current density and physical properties of the liquid phase. Experimental results are also fitted with empirical equations which relate gas hold up, bubble rise velocity, and average bubble diameter with the current density and viscosity of the medium.

Keywords: Electroflotation, Hydrodynamics, Bubble size, Current density

IPC Code (s): C25D, G01N30/00

 

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 258-262

Role of momentum exchange coefficient in circulating fluidized-bed

Shriram Prasad* & Alok Gautam

The interphase momentum exchange coefficient play an important role in formulating the mathematical description of Circulating Fluidized-Bed (CFB) system. The present study provides a theoretical and numerical investigation and its effects on various parameters. The relevancy of evaluation of interphase momentum transfer and its effect on the voidage profile is discussed. The analyzed numerical result provides a broader perspective for the range of variation of computed data. The results are very near to reality.

Keywords: Circulating fluidized-bed (CFB), Momentum exchange coefficient (b A), Voidage factor, Bed height

IPC Code(s): B01J8/24

 

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 263-268

Dissolution kinetics of iron and aluminium from red mud in
sulphuric acid solution

Deger Uzun & Mustafa Gülfen*

Dissolution kinetics for the removals of iron and aluminium from red mud, a by-product or waste of the Bayer Process, with sulphuric acid were studied. The process parameters studied include calcination temperature, sulphuric acid concentration, particle size, agitation rate, dissolution temperature and time. Temperature and acid concentration had strong influence on the dissolution of iron and aluminium. The mechanism for the dissolution of both iron and aluminium followed first order kinetic model equation (F1), -ln(1-a) = kt, controlled by interfacial chemical reaction, with the apparent activation energies of 61.42 and 7.39 kJ/mol, respectively. Using 6 M acid, the removals of 97.46% iron and 64.40% aluminium were achieved from red mud calcined at 873 K.

Keywords: Dissolution kinetics, Red mud, Iron, Aluminium, Sulphuric acid

IPC Code(s): C22B3/00

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 269-275

Solvent extraction of Cu(II) by purified cyanex 272

R K Biswas* & H P Singha

The solvent extraction of Cu(II) from 0.10 mol/dm3 sulphate medium by purified cyanex 272 (bis-2,4,4-trimethylpentylphosphinic acid, BTMPPA, H2A2) dissolved in distilled aliphatic kerosene has been investigated. The equilibration time is less than 15 min. The distribution ratio is found to decrease appreciably with equilibrium Cu(II) concentration in the aqueous phase, particularly, at its higher concentration region indicating some sort of association of Cu(II) species in either of the phases. The pH and the extractant concentration dependences on distribution ratio are 1 and 1.2, respectively. The distribution ratio is almost independent of sulphate ion concentration in the aqueous phase. The D H value is 27.3 ± 0.5 kJ/mol. The 60% extraction equilibrium reaction is suggested to be: CuHSO4+ + H2A2(o) Ç CuHSO4 A. 0.5 H2A2(o) + H+ and some 40% extraction is likely to occur via the reaction, CuHSO4+ + 1.5 H2A2(o) Ç CuHSO4A.H2A2(o) + H+ satisfying the extractant dependence of 1.20. The apparent extraction equilibrium constant (Kex) is estimated to be 10- 3.15. The loading capacity of BTMPPA is 13.47 g Cu(II)/100 g BTMPPA. Among H2SO4, HCl and HNO3 solutions as stripping agent, 1 mol/dm3 H2SO4 solution is found to be the best; 99.6% Cu(II) in the organic phase can be stripped off in three stages (O/A = 1 in each stage). The Cu(II) distribution ratio measured at pH = 4 in different diluents does not show good correlation with the cross-sectional area of BTMPPA molecules at interfaces formed by different diluents at pH 0.80.

Keywords: Liquid-liquid extraction, Copper(II), Sulphate medium, Cyanex 272, BTMPPA, Kerosene

IPC Code(s): B01D11/00, C22B3/26

 

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 276-282

 

Adsorption of As(V) from aqueous solution by chemically doped coir pith carbon

R Selvakumar*, S Kavitha & K Swaminathan

The present work examines the possible use of coir pith, a by-product from coir fibre industry as a means of removing As(V) from aqueous solution. Kinetic and equilibrium experiments were performed in order to evaluate the efficiency of the thermally activated coir pith carbon (TCPC). The efficiency of TCPC was improved by doping with FeSO4.7H2O (FCPC) and CuSO4.5H2O (CCPC). Adsorption studies were carried out using these doped and undoped coir pith carbon. Maximum removal was observed with FCPC with a Qo value of 18.9 mg/g followed by CCPC with Qo value of 14.77 mg/g at maximum As(V) concentration. TCPC was comparatively less efficient when compared to the doped adsorbents and had a Qo value of 8.39 mg/g. The rate of adsorption was dependent on the As(V) concentration. Langmuir and Freundlich isotherms were applied and the experimental data fitted well with these isotherms. The desorption and regeneration studies revealed that FCPC after regeneration could remove 62.8% As(V) when recycled. The results indicate that FCPC could be used as an effective adsorbent for As(V) removal from ground water sample.

Keywords: Coir pith, As(V) removal, Thermal activation, Doping, Isotherm studies

IPC Code(s): B01D17/00: 15/00

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 283-291

An integrated investigation of volatile organic compounds emission in the atmosphere from refinery and its off-site facilities

G H Pandya*, V K Kondawar & A G Gavane

The volatile mono and polyaromatic hydrocarbons were monitored in the ambient air and workplace of a refinery. Battery operated samplers with adsorption tubes were used for sampling the volatile hydrocarbons. The samples were subsequently thermally desorbed and analyzed using GC/MS system equipped with EI Detector. The levels of these aromatic chemicals decreased with distance from the source to the boundary walls of the refinery indicating that the impact on the neighbourhood environment is negligible. The high benzene to toluene ratio indicates that the leaks in the valves, compressors contribute to high emissions at the workplace. The volatile organic compounds were also monitored at some offsite facilities at ETP, Tank Farm, Pump House, and Gantry Terminals to have first hand information on status of these uncontrolled emissions during loading, unloading of petroleum liquids.

Keywords: VOCs, BTEX, Refinery, Gantry

IPC Code(s): C10G17/00

 

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 292-300

Esterification of salicylic acid with methanol/dimethyl carbonate over anion-modified metal oxides

Joyce D’Souza & N Nagaraju*

The esterification of salicylic acid to methyl salicylate over solid acids such as zirconia, alumina and silica and their sulphate, phosphate and borate modified forms, has been studied for the first time in an autoclave under autogenous conditions using methanol and dimethyl carbonate to compare their methylating ability. Metal oxides such as zirconia, alumina and silica as well as their sulphate, phosphate and borate modified forms are effective catalysts for the conversion of salicylic acid to methyl salicylate. Superacid, sulphated zirconia, is the most suitable catalyst due to high yield, selectivity, reusability and the simple method used for the preparation of the catalyst. The percentage yield of methyl salicylate was found to be higher when methanol was used as the methylating agent over these catalysts rather than dimethyl carbonate. Hence, methanol appears to be a better methylating agent compared to dimethyl carbonate in terms of yield as well as atom economy. The influence of reaction temperature, amount of catalyst, duration of reaction and molar ratio of salicylic acid: methanol/dimethyl carbonate has been studied over sulphated zirconia.

Keywords: Esterification, Autogenous conditions, Methanol, Dimethyl carbonate, Methyl salicylate, Isoamyl salicylate, Sulphate-, borate- and phosphate-modified zirconia, Alumina, Silica, Solid acids

IPC Code(s): C07C67/00

 

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 301-307

Hydration of calcined bentonite Portland blended cement pastes

H H M Darweesh & Z A Nagieb*

The formation of free lime (CH) during the hydration of Ordinary Portland Cement (OPC) decreases the durability of cement structures. The pozzolanic properties of calcined clays allow to avoid this drawback. So, the reaction kinetics of the OPC/calcined bentonite blended cement pastes were investigated. The results show that the water of consistency as well as setting time increase gradually with the addition of calcined bentonite at the expense of OPC. The combined water content also increases with the substitution of OPC by calcined bentonite up to 9-12 mass% and then decreases. The free lime content increases up to 3-7 days and then decreases. Also, the bulk density increases slightly, while the apparent porosity decreases. The compressive strength increases sharply up to 28 days, and slightly increases up to 90 days due to the pozzolanic reactions of calcined bentonite. The cement pastes containing 12 or 15 mass% bentonite were adversely affected at all curing ages of hydration. The SEM micrographs indicate that the hydration products of the OPC/calcined bentonite cement pastes are the same as those of the pure OPC pastes, but with different ratios, crystals and morphologies.

Keywords: Blended cement, Hydration, Free lime, Combined water, Porosity, Density

IPC Code(s): C04B7/02

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 308-312

Indirect complexometric determination of thallium(III) in its alloys and complexes using thiomalic acid as a selective releasing agent

P Parameshwara, J Karthikeyan, A Nityananda Shetty* & Prakash Shetty

A simple and selective complexometric method for the determination of thallium in presence of other metal ions is proposed on the basis of selective masking ability of thiomalic acid towards thallium(III). Thallium present in a given sample solution is first complexed with a known excess of EDTA and the surplus EDTA is titrated with standard lead nitrate solution at pH 5-6, using xylenol orange as the indicator. A 0.6% aqueous solution of thiomalic acid is then added to displace EDTA from the Tl(III)-EDTA complex. The released EDTA is titrated with standard lead nitrate solution. Reproducible and accurate results are obtained for 3-92 mg of Tl(III) with relative error less than ± 0.17% and coefficient of variation not more than 0.36%. The interference of various ions is studied. This method is used for the analysis of thallium in its synthetic alloy mixtures and also in complexes.

Keywords: Thallium(III), Thiomalic acid, Masking agent, Complexometric titration

IPC Code(s): C01G15/00, C01B6/06

 

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 313-316

Quantification of an antiviral drug (stavudine) by three procedures based on redox and complex formation using N-bromosuccinimide

K Basavaiah*, V Rama Krishna & U R Anil Kumar

Three simple, sensitive and rapid methods are described for the determination of stavudine (STV) in bulk drug and in formulations using N-bromosuccinimide (NBS) as the oxidimetric reagent. In titrimetry, an aqueous solution of STV is titrated directly in HCl medium with NBS using methyl orange as indicator. Spectrophotometric methods involve the addition of a known excess of NBS to STV in HCl medium followed by estimation of the unreacted oxidant by two reaction schemes involving the use of iron(II) and thiocyanate (method A) or tiron (method B). In all the methods, quantification is based on the amount of NBS reacting with STV. Calculations in titrimetry are based on a 1:2 (STV:NBS) reaction stoichiometry and the method is applicable over 1-9 mg range. In spectrophotometric methods, the absorbance is found to decrease linearly with STV concentration. Beer’s law is obeyed over the ranges 0.5-4.0 and 1.5-18 µg mL- 1 for method A and method B, respectively. The calculated molar absorptivity values are 6.5×104 and 1.1×104 L mol- 1cm- 1 for method A and method B, respectively. The limits of detection (LOD) and quantification (LOQ) are also reported for both methods. The RSD values for intra-day and inter-day precision studies were <2.5 and 3.0%, respectively. The procedures were successfully applied for the determination of STV in pharmaceutical formulations with good recovery, good accuracy and precision, and without measurable interference by the excipients.

Keywords: Stavudine determination, Spectrophotometry, N-bromosuccinimide, Pharmaceuticals

IPC Code(s): A61K

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 317-320

Relationship of z-tensile strength with in-plane strength properties of paper

S P Singh

Several methods are available for the measurement of strength of paper in the thickness direction. However, the values obtained from these methods are highly correlated with each other and also with the in-plane strength measurements. The relationship between z-direction tensile strength and in-plane tensile index of handsheets made at varying extents of pulp beating, types of strength aids and doses of strength aids has been studied. It has been noticed that the z-direction tensile strength of paper can be expressed in terms of in-plane tensile index by a single relationship whether the tensile index is changed by refining, or by adding strength aids, or by increasing the dose of the strength aid. In practice, an appropriate value of tensile index may be specified to ensure adequate performance of the paper even when it is subjected to stresses in z-direction.

Keywords:z-Direction tensile strength, Tensile index, Strength aids

IPC Code (s): D21H15/00

Indian Journal of Chemical Technology

Vol. 14, May 2007, pp. 321-324

Sulphonated lignin based screen ink formulations

S A Mandavgane* B B Gogte & D Subramanian

An attempt is made to develop a screen ink composition, based on lignin obtained from black liquor as a partial replacement for conventional alkyd resin. Lignin has been used as a replacement for alkyd resin to an extent of 35%. Unlike the conventional alkyd resin, efforts were made to prepare a novel alkyd resin with short oil length (20%) using chain stopper. The overall consumption of petroleum solvent in ink is around 16% which is much lesser than conventional ink which utilizes around 40% solvent. The physicochemical and film properties of ink have been studied and compared with commercial sample. The cost of the present product is less than the conventional product.

Keywords:Alkyd resin, Black liquor, Lignin, Linseed oil, Screen ink

IPC Code(s): C09D11/00, C08G