Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 131-136

 

Extraction of natural colourants from roots of

Morinda angustifolia Roxb.__ Their identification and

studies of dyeing characteristics on wool

R Bhuyan & C N Saikia*

The colour components in the roots of the plant Morinda angustifolia Roxb. were isolated and their structures were elucidated based on chemical and spectroscopic investigations. Further, the dyeing behaviour of the colour component on wool in aqueous medium was also evaluated. Depending on concentrations of dye (1-5%) in the dye bath, the dye absorption on the fibre varied from 12.50-31.58%. The fastness properties of the dyed yarns were determined. Optical densities (OD) and colour strength (K/S) values of the dye solutions as well as the dyed yarns and also colour co-ordinates for dyed yarns were determined.

 

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 137-142

 

Determination of some metal ions in aquatic environs by atomic absorption spectrometry after concentration with modified silica

A A Hanna*, Kh S Abou-El-Sherbini, E Elzahany & M A Hamed

N-propylsalicylaldimine based on porous silica, as ion exchanger, is used for the separation and preconcentration of Fe3+, Co2+, Ni2+ and Zn2+ from surface water samples collected from eleven locations at Nile river, Mediterranean and Red seas and Mansoura city tap water. The effects of pH, time of stirring, concentration of eluting acids and some common ionic species on the separation and preconcentration of the investigated metal ions in synthetic aqueous solutions are studied. The results indicate that the optimum conditions for separation are pH = 9.0-9.5 and time of stirring = 30 min. HCl is better eluent for the investigated metal ions than HNO3 except for Fe3+. Citrate and EDTA show severe interference on the recovery of the metal ions, therefore, the water samples are previously oxidized to digest organic matter prior to the application process.

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 143-149

 

 

Effect of beneficiation on the performance of iron Fischer-Tropsch catalyst in coal conversion

Y C Dasandhi* & P Bandopadhyay

In the present investigation, raw and beneficiated haematite iron ores have been used for preparation of catalysts keeping promoters content same. Since on beneficiation, catalysts activity have been increased in case of haematite ores, only beneficiated magnetite ores with same promoters were used for catalysts preparation. The catalyst prepared from fairly pure ferric nitrate shows the highest activity. On the basis of activity and selectivity obtained by using different catalysts, the raw materials have been graded according to their activities. From the experimental results it can be concluded that beneficiated magnetite has good technological feasibility and economic viability for commercialization as raw materials for preparation of catalyst for use in coal conversion by Fischer-Tropsch process.

 

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 150-153

 

Influence of humic acid on ionisation constants of

sulphurous acid: Calcium sulphite precipitation during clarification of cane juice

Mahendra Prasad & Kaman Singh*

 The presence of humic acid seems to decrease the rate of CaSO3 precipitation during clarification of cane juice in the sugar manufacturing. The first and second ionisation constants of H2SO3 were found to decrease by 8 and 13% at RT in presence of humic acid in solution, respectively. However, the first and second ionisation constants of the acid were affected in the range 19-16% respectively across the temperature range 50-90°C. In the presence of humic acid the activation energy was found to increase. The nature of positive slope of Arrhenius plot indicates the diffusion controlled reaction in the precipitation reaction which is consistent with low value of activation energy of ionisatiion of sulphurous acid.

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 154-158

 

Electroless nickel deposition on mild steel by using a new bath formulation and its characterization

Rahul A Babhale, R S Sonawane, S S Bodhale, S K Apte & B B Kale*

A new bath formulation has been developed to prepare the Ni-P deposits on mild steel substrates. The alkaline bath formulation contains NiCl2 as a Ni source and sodium hypophosphite as reducing agent. The Ni-P alloy with higher phosphorus content was obtained by using this new bath formulation. The uniform deposits of Ni-P (1.98-12.5) were obtained. The change in rate of deposition with time, temperature and pH was studied. The effect of concentration of nickel and reducing agent on the deposition was investigated. The samples obtained were characterized by using SEM, XRD, DSC and ICP-OES techniques. The Ni-P deposits were amorphous in nature and upon heat treatment in between 300 to 450°C, it changes to crystalline Ni3-P phase. The phosphorus content of the deposits increases with the deposition time and highest P content is obtained on the samples prepared at 3 h time.

 

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 159-165

 

 

Chemical recycling of galvanized steel scrap

M N C Ijomah*  & A I Ijomah

The chemical recycling of galvanized steel was investigated by preferential dissolution of the galvanized coating (dezincing or degalvanization) in a variety of acidic environments comprising dilute and moderately concentrated nitric, hydrochloric and sulphuric acids. Weight loss immersion tests were conducted for galvanized steel in the various acidic environments. It was generally observed that the more concentrated acids (10% or more) reacted or dezinced much faster with greater inherent attack on the steel substrate while the more dilute acids (2% or less) reacted very slowly with partial or ineffective dezincing. Optimum results were obtained at intermediate (5%) acid concentrations with little or no attack on the underlying steel substrate, except in 5% HNO3. It was suggested that two competing cathodic reactions, hydrogen evolution and oxygen reduction, simultaneously occurred in this characteristic oxidizing environment (5% HNO3) leading to high corrosion rates observed, the remedy of which lies in electrolyte deaeration or use of appropriate corrosion inhibitors. These findings were fully supported with optical microscopy. The various factors favouring or hindering the galvanized steel recycling and the scope for possible scrap product utilization were discussed.

 

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 166-174

 

 

Studies on biobleaching of kraft pulp using Phanerochaete chrysosporium

Sk Masud Hossain*, Manas Das, S H Ibrahim & N Anantharaman

White-rot fungi Phanerochaete chrysosporium can degrade residual lignin (bleach) of kraft pulp maximum 69.59 percent within 7 days (optimum digestion time) with 20 percent inoculum concentration (optimum) of 7 days old aged (optimum) fungus with 1.0 percent (w/w percent of pulp) (optimum) of glucose and 0.10 percent (w/w percent of pulp) (optimum) of l-asparagine at pH 4.5 and temperature 35°C. COD, BOD and colour of the effluents (filtrate after digestion with microbe) at optimum conditions are very lower. Average COD, BOD and colour values of effluents after bleaching for optimum dose are 320 mg/L, 545 mg and 0.23 (OD at 465 nm) respectively. The increase percentage of brightness, tear index, burst index, tensile index and breaking length of bleached pulp for optimum dose are 89.35, 38.93, 47.46, 68.17 and 66.97 respectively.

 

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 175-179

 

 

Photoinduced conductivity changes of polyvinyl esters and polyesters with azo chromophores

Gigy Abraham & E Purushothaman*

The photoinduced changes in conductivity of polyvinyl esters having pendant azobenzene groups and polyesters with azo groups in the polymer backbone are described. Reversible photoincrease in conductivity was observed in all the cases. A reasonable explanation has been offered for the photoeffect on conductivity.

 

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 180-185

 

 

Synthesis and characterization of poly(piperazinyl phosphorimine) and its metal complexes in aqueous medium

S Kumaresan & P Kannan*

 Poly(piperazinyl phosphorimine) was prepared by Schotten-Boumann method using phosphorus oxychloride and piperazine at room temperature. Polymer metal complexes were prepared in aqueous solutions using divalent metal salts viz. Cu(II), Ni(II), Mg(II), Ca(II) and Cd(II) with the polymer. Spectral evidences confirmed the formation of the metal complexes. Thermogravimetric analysis and differential scanning calorimetry were employed to investigate the thermal stability of the polymer and its metal complexes. The IR spectroscopy of the polymer and complexes suggests that metals could be co-ordinated through oxygen of the phosphorimine group and tertiary nitrogen atom. The DRS, EPR and magnetic moments confirmed the complex formation and showed the geometry of the complexes. Small angle XRD pattern shows that the polymer was amorphous, whereas the complexes were crystalline. Energy dispersive X-ray crystallographic studies confirmed the metal incorporation in the polymer chain.

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 186-191

 

 

Synthesis and ion-exchange behaviour of acrylamide zirconium(IV) phosphate: A novel crystalline and Hg(II) selective hybrid inorganic ion exchanger

K G Varshney*, Vandana Jain & Namrta Tayal

A new phase of hybrid material, acrylamide zirconium(IV) phosphate, has been synthesized and characterized with the help of ion exchange, IR, TGA and XRD studies. The ion-exchange and distribution studies indicate that the material is highly selective for mercury. On this basis some binary separations have been performed on its column thus exploring its analytical potential.

 

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 192-196

 

 

Photoinitiated copolymerization of citronellol and methylmethacrylate

Prachi Pandey & A K Srivastava*

Free radical copolymerization of citronellol and methyl-methacyrlate (MMA) in xylene at 30±0.2°C using benzoylperoxide (BPO) as the photoinitiator for 21 h has been carried out. The system follows non-ideal kinetics (Rp a[BPO]0.62 [citronellol]0.87 [MMA]0.90) due to both primary radical termination and degradative chain transfer reaction. Analysis of the copolymer by IR and NMR shows the presence of alcoholic and acrylate group in the copolymer. The glass transition temperature of copolymer, calculated by differential scanning calorimetry (DSC) is 80oC. The nearly alternating nature of the copolymer is confirmed by the product of reactivity ratios r1 (MMA)=0.062 and r2 (citronellol)=0.005, calculated by Kelen-Tüdos method. The Alfrey-Price, Q-e parameters for citronellol have been calculated as –1.09 and 1.47. The mechanism has also been explained.

 

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 197-200

 

 

Grafting ethyl methacrylate onto partially hydrolysed starch using ceric ion as initiator

F E Okieimen

Poly(ethyl methacrylate) has been grafted onto partially hydrolysed starch (84.04% conversion) by using ceric ion redox initiator in an aqueous medium at 29oC. The extent of graft polymer formation was measured in terms of conversion of monomer to polymer, graft level, molecular weight of grafted polymer chains and grafting frequency as a function of ceric ion concentration. It was found that an eight-fold increase in ceric ion concentration was accompanied by marked changes (of about three-fold in graft level, six-fold in molecular weight of grafted polymer chains and four-fold in grafting frequency) in the values of the measured grafting parameters. A ten-fold increase in the polymeric substrate to dispersion medium ratio was found to increase the extent of graft polymer formation onto partially hydrolysed starch.

 

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 201-210

 

Adsorption performance of Zr-pillared montmorillonite for the removal of organic pollutants from aqueous phase

V P Vinod, Sumol Varghese & T S Anirudhan*

 This study examined the effectiveness of Zr-pillared Na-rich montmorillonite (PILC) in removing humic acid (HA) and tannic acid (TA) from aqueous solutions by adsorption. Batch experiments were conducted to evaluate the pH effects, the kinetics, temperature effects and sorption isotherm on the HA and TA adsorption onto PILC. The research demonstrated that the PILC could sufficiently remove HA and TA from aqueous solutions. The most effective pH range was found to be 3.0 to 4.0 for both HA and TA. The kinetic studies showed that an equilibrium time of 6 h was needed for the adsorption of HA and TA on PILC and adsorption rates could be described by a first-order Lagergren equation. The adsorption of HA and TA was found to increase with ionic strength due to the compression of diffuse double layer. The equilibrium isotherm data for both HA and TA fitted Langmuir isotherm model and based on Langmuir constants, the PILC had a greater adsorption capacity for HA than for TA. The isosteric heats of the adsorption process were determined at various surface coverages of the adsorbent. The thermodynamic parameters such as change in free energy (DGo), enthalpy (DHo), and entropy (DSo) were derived to predict the nature of adsorption. Sheindrof-Rebhun-Sheintuch isotherm model was used to study the competitive interaction for the adsorption of single component from mixture by PILC. About 91.4 and 94.8% of HA and TA can be recovered from the spent adsorbent by controlling the pH at 11.0.

 

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 211-216

 

 

Removal of basic dye from industrial waste water

by adsorption

Arvind K Singh & Prem N Tiwari*

For proper understanding, the process of removal of solute dye by adsorption and to reveal the manner in which this adsorption process can be adopted for removal of the solute material from the solution, the study of isotherm, kinetics and thermodynamic parameters is of paramount importance. The growth of adsorption with time is function of the initial concentration, temperature and pH of the system. The kinetics of adsorption was found to be of first order with intra-particle diffusion at the rate-controlling step. The values of different thermodynamic properties such as DG0, DH0 and DS0 indicate that the process is spontaneous, feasible and exothermic in nature. The adsorption process satisfies Langmuir isotherm.

 

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 217-222

 

Cashewnut sheath carbon: A new sorbent for

defluoridation of water

R Sivabalan, S Rengaraj, Banumathi Arabindoo & V Murugesan*

 

Cashewnut sheath, an agricultural waste discarded largely in India is identified for the preparation of an effective sorbent for fluoride removal. Experiments were conducted for the sorption of fluoride from aqueous solution using activated carbon from cashewnut sheath (CSC) in two phases, namely, batch studies and column studies. The influence of pH, adsorbent dose, particle size and contact time was investigated in batch studies. The adsorption process follows Freundlich adsorption isotherm. Continuous flow experiments in fixed bed columns packed with activated carbon were carried out in order to assess the feasibility of this for field applications. The carbon bed after exhaustion was regenerated with 0.1 N hydrochloric acid. The influence of initial concentration of fluoride ion, flow rate, particle size and concentration of the regenerant on the performance of the column was studied. Comparative study was conducted with commercially available carbon impregnated with 2% aluminium sulphate solution. The results revealed that CSC is found to be active and efficient for fluoride removal.

 

 

Indian Journal of Chemical Technology

Vol. 10, March 2003, pp. 223-236

 

 

Louis Paul Cailletet—The liquefaction of the permanent gases

Jaime Wisniak*

 

To Louis Paul Cailletet (1831-1913) we owe the realization of the liquefaction of permanent gases using a free expansion process. A brilliant analysis of an experimental mishap led him to achieve this possibility. The priority of oxygen liquefaction was and continues to be a matter of discussion. The life and scientific work of Cailletet are described together with details about the priority polemic.