Indian Journal of Chemical Technology

Research articles

Complexometric method for the determination of mercury using sodium metabisulphite as selective masking reagent IPC Code: G01N33/20, 31/16 Prakash Shetty & A Nityananda Shetty	163

Removal and recovery of low salt dye golden yellow LS by liquid-liquid extraction IPC Code:C02F1/26, C09B69/00 G Muthuraman & K Palanivelu	166

Role of matrix material in the characterization of high-purity copper by flame and graphite furnace AAS IPC Code: C25C Sanjukta A Kumar, Manisha B Sanglikar, Mahzebin S Shaikh & M Sudersanan	170

Ultrasonic studies on sodium thiosulphate and ammonium thiosulphate in water and water + acetone mixtures IPC Code: G01N29/02,29/18 U N Dash, G S Roy & S Mohanty	178

Study on the fluoride removal characteristics of mineral (fluorapatite) IPC Code: C02F1/28 I B Singh & M Prasad	185

Adsorption studies of heavy metal ion by low cost agricultural by-products Bajra powder IPC Code: B01J20/22(C02F1/28,101:20) Mazhar Farooqui, Sayyad Sultan, Maqdoom Farooqui & S H Quadri	190

Adsorption equilibrium study: Removal of dyestuff effluent using sawdust, polymerized sawdust and sawdust carbon – I IPC Code: C02F1/42//C09B, B01J20/20 D N Jadhav & A K Vanjara	194

Preparation and characterization of transition metal ion-selective membrane electrodes IPC Code: G01N27/333 S K Menon, S Amarchand & Y K Agrawal	201

Role of triethanolamine and furfuraldehyde on the electrochemical deposition and dissolution behaviour of zinc IPC Code: C25D3/22 A John Rethinam, G N K Ramesh Bapu & V S Muralidharan	207

Thermal, spectral and morphological studies on cellulose diisoamylaminophosphate in air IPC Code: C08B Rajesh Trehan, G L Kad, Rani Jindal, Krishan Lal & Sanjiv Arora	213

Treatment of oily water with human hair as a medium: A preliminary study IPC Code: E02B15/04 Z V P Murthy, Gautam Kaushik & Ritesh Suratwala	220

Flyash based zeolite-A: A suitable sorbent for lead removal IPC Code: (C02F1/28,101:20)//B01J20/18 Pawan Kumar, Sadhana Rayalu & Suresh M Dhopte 227	227

Copolymerisation behaviour of methyl methacrylate with 2-methyl-acrylic acid 2-(3-phenyl-acryloyloxy)-ethyl ester IPC Code: C08F120/18 Alpana Mishra & Veena Choudhary	234

Dimensional stability and fungal decay of rubber wood-polymer composites processed by gamma radiation IPC Code: B27K3/15, 3/34 S K Gupta, N K Gupta, R Singhal& A K Nagpal

Catalytic oxidative transformation of benzyl alcohol and cyclohexanol over
mesoporous Mn-MCM-41, Mo-MCM-41 and Mo(Im), Mn-MCM-41 molecular sieves IPC Code: B01J29/035, C07B31/00 A Pandurangan, S Vetrivel & B Anthea	248

Alkylation of aniline with ethanol over Zn_1-xMn_xFe₂O₄(x= 0, 0.25, 0.50, 0.75 and 1) ferrite system IPC Code: C0 7B37/00,211/46 Reena Dwivedi, A Radhe Shyam, R Prasad & H P S Chauhan	254

Synthesis and characterization of SAPO-35 from non-aqueous systems with different silicon content IPC Code: B01J29/85 N Venkatathri & S Sivasankar

Photoperoxidation of nitrobenzene in aqueous phase IPC Code: (C02F1/32,101:38) S Mary Celin, M Pandit, J C Kapoor & R K Sharma	266

Corrosion inhibition of tin by some amino acids in citric acid solution IPC Code: C23F11/10 M A Quraishi, F A Ansari & D Jamal	271

Educator

John Herapath-The beginning of the kinetic theory of gases Jamie Wisniak	275

Announcement	286

Chem-Tech Scan	287

Author Index	291

Keyword Index	292

Complexometric method for the determination of mercury using sodium

metabisulphite as selective masking reagent

A selective complexometric method is described for the determination of mercury(II) using sodium metabisulphite as a masking reagent. An excess of EDTA is added to mercury(II) solution containing associated diverse metal ions and the surplus EDTA is back titrated at pH 5-6 (hexamine buffer) with standard zinc sulphate solution using xylenol orange as indicator. An aqueous solution of sodium metabisulphite is then added to displace EDTA selectively from Hg-EDTA complex and the released EDTA is then titrated against the same standard zinc sulphate solution. Reproducible and accurate results are obtained in the range 4-100 mg of mercury with a relative error £ 0.26% and coefficient of variation £ 0.40%. The method is useful for the analysis of mercury in complexes and alloy samples.

Removal and recovery of low salt dye golden yellow LS by liquid-liquid extraction

A laboratory study on liquid-liquid extraction of a low salt textile dye namely Golden Yellow LS, an anionic type, was investigated for its removal and recovery from aqueous solution using Tri-n-butyl phosphate (TBP) and hexane. The dye was extracted into the solvent mixture from acidic medium. The extracted dye can be recovered by stripping into alkali solution. The solvent can be reused after stripping the dye. The influence of parameters such as dye concentration, pH, solvent composition, salt concentration, equilibration time, aqu./org.volume ratio, the percentage removal and recovery of the dye were studied.

Role of matrix material in the characterization of high-purity copper

by flame and graphite furnace AAS

Sanjukta A Kumar, Manisha B Sanglikar, Mahzebin S Shaikh & M Sudersanan*

Matrix effect in the determination of trace metallics in high-purity copper has been evaluated for estimation of Ag, Cr, Fe, Ni, Pb, Sb and Zn by FAAS and GFAAS. Matrix effects were less significant for FAAS while it was quite important for GFAAS. Methods have been standardized for determination of various trace elements after separation of matrix element and pre-concentration of the analytes. For separation of matrix two different procedures were standardized; (i) co-precipitation of metal hydroxides using La as carrier and (ii) electro-deposition. To validate the method, the recovery of metal ions were tested and were found to be satisfactory. The methods have been applied to the determination of these impurities in high-purity copper samples. For the determination of silver, a selective deposition method was adopted in order to avoid co-deposition of copper. These three different modes of matrix separation were found to be complementary to each other for determination of various critical trace elements in high-purity electrolytic copper.

Keywords: Copper, Silver, Flame furnace, Graphite furnace, Matrix effects, Co-

Ultrasonic studies on sodium thiosulphate and ammonium thiosulphate in

water and water + acetone mixtures

Densities at 298.15, 303.15, 308.15 and 313.15 K and ultrasonic velocities at 303.15, 308.15 and 313.15 K are measured for the solutions of sodium thiosulphate[Na2S2O3] and ammonium thiosulphate[ (NH4)2S2O3] in water and water + acetone (5, 10 and 20 wt %) mixtures with the objective of evaluating the apparent molar properties and acoustic parameters. The results are discussed in terms of ion-ion and ion-solvent interactions and structural effects of the solvents in solution.

Keywords: Ultrasonic studies, Sodium thiosulphate, Ammonium thiosulphate, Density,

Study on the fluoride removal characteristics of mineral (fluorapatite)

The effectiveness of low grade fluorapatite bearing mineral on fluoride removal has not been examined earlier. For identification of such mineral, a preliminary assessment of performance of mineral is essential in order to know which aspect is necessary to carry out further research for development of mineral based defluoridation technology. In this study, batch adsorption study was performed to evaluate the fluoride removal potential of low cost rock phosphate (fluroapatite) mineral at pH 4, 5 and 6. The optimum dose was determined to be 1.5, 2.5 and 3.5 g mineral at pH 4, 5 and 6, respectively. The first order adsorption rate constants derived by Lagergren equation at different pH, clearly indicates the fast removal kinetics at pH 4. The comparatively high solubility of mineral and an increase of calcium concentration at pH 4 appears to be the main reason for fast removal reaction. There was no effect of mineral quantity on fluoride removal after solution pH became alkaline. The various aspects of the study including recyclability of mineral are discussed.

Keywords: Fluorapatite, Fluoride removal, Defluoridation technology, Adsorption,

Adsorption studies of heavy metal ion by low cost agricultural by-products- Bajra powder

The presence of heavy metals in the environment represent a very significant and long term environmental hazard. Many industries such as electroplating industry, organic inorganic chemical, petrochemicals, fertilizer etc discharge effluent containing high level of metal ions. In the present paper, a study on the adsorption of Cu(II), Cr(VI), Fe(II) & Ni(II) by an agricultural by – product i.e. powder of Bajra was carried out. The effects of solution pH, initial concentration, adsorbent amount, temperature and contact time were studied. In batch experiments, adsorption of these metal ions increases with decrease in initial concentration of metal ion and adsorbent dosage. Measured values have been found to follow Langmuir and Freundlich adsorption isotherms.

Keywords: Adsorption, Heavy metal ion, Bajra powder, Langmuir adsorption isotherm,

Adsorption equilibrium study: Removal of dyestuff effluent using sawdust,

polymerized sawdust and sawdust carbon - I

The adsorption equilibrium study of three different types of dyestuff effluent on the sawdust, polymerized sawdust and activated carbon prepared from sawdust has been studied. The applicability of the Langmuir and Freundlich equation has been tested for equilibrium data of which Freundlich isotherm model is found to be the most appropriate. From the equilibrium data it is observed that sawdust, polymerized sawdust and sawdust carbon are good adsorbents for removal of acidic, basic and disperse dyes from dyestuff effluents. The pH has significant influence on the adsorption. Acidic and disperse dyes show higher adsorption at higher pH, whereas, basic dyes show higher adsorption at lower pH.

Keywords: Adsorption, Sawdust, Polymerized sawdust, Sawdust carbon, Dyestuff effluent, Langmuir equation, Freundlich equation

Preparation and characterization of transition metal ion-selective membrane electrodes

Ion selective electrodes of transition metal ions Co(ll), Cu(ll) and Zn(ll) have been fabricated using the corresponding hydroxamate complexes. These electrodes have been systematically characterized by studying the response time, electrode response, pH range and selectivity coefficients over closely associated metals. The electrode response in non-aqueous and the stability over the medium have been studied.

Keywords: Ion selective electrodes, Transition metal ions, Co(II), Cu(II) and Zn(II),

Role of triethanolamine and furfuraldehyde on the electrochemical

deposition and dissolution behaviour of zinc

The search for the development of non-cyanide zinc plating baths resulted in identification of newer complexing ligands. The deposition and dissolution of zinc was studied by cyclic voltammetric studies using a bath composition consisted of 0.12M zinc oxide, 2.75M sodium hydroxide and required quantity of triethanolamine and furfuraldehyde. Glassy carbon (GC), Platinum and SCE were used as working electrode, counter electrode and reference electrode respectively. The studies were made at different concentrations of the above additives at various scan rates at 30°C. The pH of the bath was maintained at 11.5 to 12.0. The deposition of zinc from zincate solutions undergoes successive reduction to zinc. The chemical step followed by first electron transfer is the slow step. Triethanolamine and furfuraldehyde were found to participate in the electron transfer process. Detailed mechanism of deposition and dissolution in presence of triethanolamine and furfuraldehyde are discussed.

Keywords: Non-cyanide zinc plating baths, Complexing ligands, Electrochemical deposition, Dissolution behaviour, Triethanolamine, Furfuraldehyde

Thermal, spectral and morphological studies on cellulose diisoamylaminophosphate in air

The thermal behaviour of cellulose and cellulose diisoamylaminophosphate (CDAP) samples having different degrees of substitution have been studied using DTA and TG techniques from ambient temperature to 700^ºC in static air. The various reactions involved, namely, dehydration, dephosphorylation, dehydrohalogenation, oxidative decomposition and oxidation of charred residue, have been discussed. Brodio method is used to obtain various kinetic and thermodynamic parameters from TG curves for different stages of thermal degradation. The values of activation energies for the oxidative decomposition of CDAP samples are found to be in the range of 49.02 – 64.19 kJmol^-1 and are lower than that of cellulose (160.74 kJmol^-1). The IR spectra of the pyrolysis residues of CDAP indicate formation of compounds containing C=O, C=C and P=O groups. The EPR signals indicate that the free radical mechanism is not dominant in the degradation of CDAP. Higher char yields of CDAP samples as compared to cellulose along with related observations suggest that CDAP is an effective flame retardant. Scanning electron micrographs of CDAP show that the fibrillar reaction sites of cellulose have mostly reacted, although the general morphology of the original fibre remains intact. Internal axial cracking and the increased surface area in the chars of treated samples show the intumescent nature of CDAP. The mechanism of thermal degradation of CDAP has been proposed.

Treatment of oily water with human hair as a medium: A preliminary study

Experiments are conducted to study the effect of human hair as an adsorbing medium for the separation of oil from water, both in free as well as in emulsified form. Effects of various parameters on the phenomenon are studied and inferences drawn, which is showing an unexpectedly high efficiency of the process. It is seen that at laboratory scale, the method is very efficient. It is nearly 100% efficient for free oil. However, the most intriguing thing observed is, its efficiency in separating emulsified oil that lied between 95 - 99%. Experiments are also conducted to study the phenomenon at the micro level. The phenomenon, as is clearly visible under the microscope, is selective physical adsorption. Also, the separation results obey Freundlich’s isotherm, thus confirming that the oil removal is due to selective adsorption. A critical point of view is kept throughout the experimentation and every care is taken to minimise the human as well as instrumental errors. Even if the process does not reduce the concentrations to micro levels, it can still reduce the cost drastically by reducing the amount of demulsifying agents required. As the process is eco-friendly and does not require any chemicals, it may lead to development of a new technique of separating oil-water emulsion, which is simpler.

Flyash based zeolite-A: A suitable sorbent for lead removal

High cost and difficulties in procurement of zeolites in India prohibits its wide spread use for environmental remediation. This problem has been overcome in this investigation by usage of cost-effective flyash based zeolite-A (FAZ-A) using process developed by NEERI, which has been patented nationally and internationally. The usage of the new material for removal of lead has been studied and results obtained are encouraging vis-à-vis commercially available zeolite-A. Pore diffusion co-efficient have been worked out and the value obtained are in the range of 1.78 - 2.82 X 10 ^–11cm²/sfor different concentrations of lead. The rate constants have been derived using Lagergren’s model indicating the reaction to be of 1st order. The linear plot suggested the applicability of Mckay’s model on mass transfer analysis to the system. The mass transfer co-efficient varies inversely with initial concentration. The data has been processed in accordance with Langmuir equation and fits well in the particular sorption model, showing the formation of monolayer coverage on zeolite surface with maximum adsorption capacity of 714.28 mg/g.

Keywords: Adsorption, Flyash based zeolite, Lead removal, Lagregren’s model,

Copolymerisation behaviour of methyl methacrylate with2-methyl-acrylic acid

2-(3-phenyl-acryloyloxy)-ethyl ester

Copolymerisation of methyl methacrylate (MMA) with varying mole fractions of 2-methyl-acrylic acid 2-(3-phenyl-acryloyloxy)-ethyl ester (B) [i.e. in the range of 0.1- 0.5 in the initial feed] was carried out at 60^°C in bulk using azobisisobutyronitrile (AIBN) as an initiator. The copolymer composition was determined from ¹H-NMR by taking the ratio of proton resonance signals due to – OCH₃of MMA (d = 3.59ppm) and -OCH₂CH₂ O- / C₆H₅CH=CH of B (d = 4.36 /6.48 ppm). Copolymerisations were terminated at low conversion (in the range of 10-15%) and the reactivity ratios were calculated using Finemann Ross and Kelen Tüdos methods. Reactivity ratios for both the monomers were higher than unity. Thermal characterisation of the copolymers was done by using differential scanning calorimetry and thermogravimetric analysis.

Fabrication of sheets was carried out by casting prepolymer syrup having very low mole fractions (~2- 10 mole %) of comonomer (B). The effect of incorporation of comonomer on the physical and mechanical properties of PMMA has also been evaluated.

Dimensional stability and fungal decay of rubber wood-polymer

composites processed by gamma radiation

An attempt has been made to improve dimensional stability and resistance to biological deterioration of rubber wood (Hevea brasiliensis) against fungal decay via preparation of wood-polymer composites (WPC). Monomer formulations based on methyl methacrylate (MMA), butyl methacrylate (BMA), acrylonitrile (AN) and styrene (ST) were used for impregnation and cobalt-60 gamma radiation source for polymerisation. Dimensional stability was measured in terms of anti-shrink efficiency (ASE), and biological deterioration in terms of weight loss caused by white and brown rot fungi during a period of 12 weeks exposure. Polymer loading (PL), in general, increased with the radiation dose upto 30 kGy. Maximum PL (~26%) was observed with BMA and minimum (~13%) with AN based formulations. Whereas, ASE improved proportionately with PL. Partial replacement of AN with MMA did not show significant effect on the said properties, that with ST lead to maximum ASE and resistance to fungal decay.

Keywords: Dimensional stability, resistance, Biological deterioration, Rubber wood, Composites, Gamma radiation, Polymer loading.

Catalytic oxidative transformation of benzyl alcohol and cyclohexanol over mesoporous

Mn-MCM-41, Mo-MCM-41 and Mo(Im), Mn-MCM-41 molecular sieves

Mesoporous Mn-MCM-41 and Mo-MCM-41 molecular sieves were synthesized by hydrothermal method using manganese chloride, ammonium molybdate and sodium metasilicate as the source for Mn, Mo and Si. Mo(Im), Mn-MCM-41 was synthesized by impregnating Mn-MCM-41 with ammonium molybdate by wet chemical method. These materials were characterized by XRD, TGA, FT-IR and ESR techniques. The vapour phase oxidation of benzyl alcohol and cyclohexanol was attempted over these molecular sieves as a probe reaction. The principal products were benzaldehyde and cyclohexanone. The activity of Mn-MCM-41 was found to be better than the other two catalysts. The influence of time on stream was studied at 300°C for both the reactions over Mn-MCM-41 and Mo-MCM-41 molecular sieves. The conversion decreased very slightly with increase in time on stream.

Keywords: Molecular sieves, Hydrothermal method, Wet chemical method, XRD, TGA, FT-IR, ESR

Alkylation of aniline with ethanol over Zn_1-xMn_xFe₂O₄

(x= 0, 0.25, 0.50, 0.75 and 1) ferrite system

N- Alkylation of aniline with ethanol has been studied in vapour phase, in a fixed bed reactor over

Zn_1-xMn_xFe₂O₄(X= 0, 0.25, 0.50, 0.75 and 1) ferrospinel system. N-ethylaniline (NEA) and N,N-diethylanilines (NNDEA) were found to be the major products. It was observed, that, systems possessing low x values are highly selective for N-ethylaniline. Reaction parameters were optimized over ZnFe₂O₄ catalyst. A maximum yield of 53 % of N-ethylaniline with selectivity of 97% and 1.79 % of N,N-diethylaniline with selectivity of 3 % was obtained over ZnFe₂O₄ catalyst at a temperature of 503K, ethanol to aniline molar ratio 6 and weight hour space velocity of 0.17 h^-1. Catalyst characterization has been made by XRD, IR spectroscopy and ammonia desorption methods. All catalysts show their characteristic M-O stretching bands around 700 and 500 cm^-1 associated with tetrahedral and octahedral sites respectively. All catalysts were found to show weak, medium and strong acidic sites corresponding to ammonia desorption at different temperature ranges 423-523, 523-623 and 623-723K. A tentative mechanism for production of N-ethylanilines has been proposed.

Keywords: Alkylation, Aniline, Ethanol, Vapour phase, Fixed bed reactor, N-ethylaniline

Synthesis and characterization of SAPO-35 from non-aqueous

system with different silicon content

The molecular sieve SAPO-35 with different silicon content has been synthesized in a non-aqueous medium using hexamethyleneimine template. It has been characterized by XRD, SEM, Carbon and Nitrogen analysis, MASNMR, FT-IR techniques and methanol to olefin reaction. The study indicates that XRD, FT-IR and ²⁹Si MASNMR properties did not change on increase in silicon incorporation. No silicon ilands were found on increase in silicon concentration. However, SEM photograph reveals that the particle size increased on increase in silicon content in the framework. The morphology also changes from bundles of plates to cuboid, on more silicon incorporation. The catalytic activity of methanol to olefin conversion increases with silicon content and the selectivity is higher than ZSM-5 catalyst. Butene is formed as a main product.

Keywords: Molecular sieves, Silicon, Hexamethyleneimine, XRD, SEM, Carbon and

Photoperoxidation of nitrobenzene in aqueous phase

Photochemical processes provide an attractive alternative to the conventional wastewater treatment technologies. This paper summarizes studies on nitrobenzene photooxidation with a 125 W medium pressure UV lamp, using H₂O₂ as oxidant. The experiments are performed in an annular type photochemical reactor of 1L capacity. The rate and extent of nitrobenzene destruction is assessed using various concentrations of H₂O₂. It is estimated that complete destruction of nitrobenzene can be achieved in 40 min at a H₂O₂ dose of 4.41 x 10^-5mM/L. Total Organic Carbon (TOC) and Total bound nitrogen (TN_b) are also removed to an extent of 90 and 40 % respectively after 1h of UV exposure indicating photoperoxidation as a potential technique to decontaminate nitrobenzene in aqueous phase.

Corrosion inhibition of tin by some amino acids in citric acid solution

Electrochemical investigations were carried out to study the corrosion behaviour of tin plate in citric acid in the absence and presence of various concentrations of amino acids, namely arginine monohydrochloride, lysine monohydrochloride, cysteine and methionine, by using potentiodynamic polarization technique. The results of this investigation revealed that nitrogen containing amino acids gave inhibition efficiency (ie) >70% at 5 ppm and sulphur containing amino acids gave ie of 69% and 56% respectively at concentration of 50 ppm.

Keywords: Corrosion inhibition, Tin, Amino acids, Citric acid, Electrochemical

John Herapath-The beginning of the kinetic theory of gases

John Herapath (1790-1868), a self-taught scientist, was the first to present a comprehensive description of the structure of a gas, in which the molecules moved and collided with each other, instead of vibrating in a fixed lattice. His model made the wrong assumption that the momentum of the molecules, instead of their kinetic energy measured the temperature. He used the model to calculate for the first time the velocity of a molecule, the velocity of sound and to describe effusion phenomenon through small pores, and adiabatic compression. His speculative approach put him at odds with the empirical approach of the British scientific establishment of his time.

ISSN: 0971-457X		CODEN:ICHTEU 11(1) 155-292
Volume 11	Number 2	March 2004