VOLUME 22, NO4, DEC 2000

Investigation of pollutants in the industrial effluents

ndustrial effluents collected from different industries of I-9 sector Islamabad were examined for different physical parameters such as pH, SS, TDS, DS, DO and GOD. Various anions such as Cl-1, SO4--2NO3-1, NO2-1 and cations viz Na+, K+, Ag+, Ca+2, pb(+2), Ca+2, Zn+2 Mn+2, Cd+2 were also investigated in the same effluents. The values were compared with standard, of NEQs and were found all parameters within the permissible limit except COD, Cl-1 l(-1) and cation like Cu+2, Zn+2, Mn+2 and Cd+2. Th, hazardous effect of these parameters have also been discussed.read more

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M ISHAQ ,NISAR AHMAD ,YOUSUF IQBAL ,SULTAN ALAM ,SHOMILA SABIR ,

Lightweight characteristics of the Naka Pabni shale in Pakistan

An investigation into bloatable raw material comprising of shale, suitable for use in making lightweight aggregate has been mode to exist in large quantities in the region of Naka Pabni located in Kirthar province to the North of Karachi. Field studies have revealed that extensive deposits of shale occur in the region Test results indicate that the material can be bloated successfully at 1,100 degreesC and the resultant bloated material becomes considerably lighter than the conventional aggregate. The expanded aggregate is hard, highly cellular and has a tough water resistant skin and uniform structural strength.read more

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SHAH ALAM KHAN ,HAMID ULLAH KHAN ,

Hydrolysis of methyl formate in aqueous solutions and the evaluation of rate constants

Emphasis has been placed on the data for the hydrolysis of methyl formate in neutral medium ova the temperature range 293-343 K to illustrate the method, employing numerical integration and the criteria of least squares for the evaluation of the first and second order rate constants in kirrman's equation by sum of trapezoids. The values obtained for second order rate constant K-1 (L mol(-1) sec(-1)) contrast the values reported in literature. The hydrolysis of methyl formate involves alkyl-oxygen cleavage.read more

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M AURANG ZEB ,NAEEM PIRZADA ,SHAKILA BEGUM ,

Pseudo-first order rate constants and thermodynamic parameters for esters hydrolysis in neutral medium

 comprehensive study of the Pseudo-first order rate constants K-0 (sec(-1)) for uncatalysed reaction and the thermodynamic parameters for alkyl formates HCOOR in neutral medium in the temperature range (293-343 K) has been undertaken The fi ee energies, enthalpies and entropies of activation were measured according to the theory of absolute reaction rates. The enthalpies and entropies of activation decreased from methyl to ethyl formates whereas the DeltaS(#) and DeltaH(#) values obtained for isopropyl formate were approximately the same as that for ethyl formate indicating that further substitution at the proportional to -C atom did not produce any further significant intramolecular polarization. The A(AL)1 mechanism was operative in neutral hydrolysis of esters.read more

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M AURANG ZEB ,SHAKILA BEGUM ,NAEEM PIRZADA ,

Detection and removal of copper from the industrial effluents

A bench scale hydrometallurgical method is proposed for the detection nd removal of copper from the effluents discharged by various industries into Kabul Rivet. The conditions, rob as, effect of cid concentration temperature and acid leaching time were optimized The effluents were ashed at 500-600 degreesC and the residue was leached with 7.5 M HCl for six hours at 80 degreesC. Almost 99% removal of copper is achieved from the acid leached solution by extraction into 5% solution of trioctylamine in benzene and subsequently stripping with 0.1 M HCl solutions. The technology developed is economically feasible because the solvents used are regenerated aml recycled just after washing with distilled water.read more

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MUHAMMAD ALI QAISAR ,KAMIN KHAN ,A RAHMAN ,M RIAZ ,M AKIF ,

Determination of physico-chemical properties and heavy metals in the effluents of match industries of Hayat Abad Industrial Estate, NWFP

Effluent samples were collected at different intervals from match industries located at Hayat Abad Industrial Estate. These samples were analyzed for their physico-chemical properties and selected toxic metals suspected to be released by match industries. The effluents of all match industries contained high concentration than the permissible level of chromium (VI), iron and manganese ranging from 11.00 +/- 0.00- 38.91 +/- 0.05 ppm, 11.76 +/-0.10-21.70 +/- .08 and 0.06 +/-0.01-2.28 +/-0.09 respectively. Other heavy metals like copper, lead, zinc and nickel were founded to be below detection limit.read more

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JASMIN SHAH ,NOOR UL ISLAM ,M RASUL JANB ,M REHMAN ,

Capillary gas chromatographic determination of vanadium in rock samples using bis (acetylpivalylmethane) ethylenediimine as complexing agent

 A capillary gas chomatographic method has boar developed for the determination of vanadium from rock samples. It is based on complexation of analyte by bis (acetylpivalylmethane) ethylanediimine (H(2)APM(2)en) followed by solvent extraction, elution and reparation through capillary gas chromatographic column BP5 (50 m x 0.22 mm i.d) with layer thickness 0.25 mum The complexing reagent and copper (II), nickel (II), palladium (II) and platinum (II) as metal chelates of H(2)APM(2)en completely separated from oxovanadium (IV). However, high concentration of iron (II) supressed oxovanadium (IV) response. Quantitation was carried out using standard addition after acid dissolution of rock samples. The amount of vanadium was found within 101.5-687.5 mug/g with relative standard deviation (RSD) 2.05-4.27 %.read more

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M I BHANGER ,ASHFAQ A MEMON ,M Y KHUHAWAR ,

Preparation, spectroscopic and magnetic characterization of Di-mu-methoxy-bis(2-amino-3-methylpyridine)(2) copper(II) with NO3-, CIO4- or CF3SO3-

Three new dinuclear copper(II) complexes of 2-mino-3-methylpyridine has been prepared and characterized by spectroscopic, magnetic and elemental analysis. Complex [Cu-2(2-amino-3-methylpyridine)(4)(OCH3)(2)] (NO3)(2) were characterized magnetically by magnetic susceptometer. The magnetic susceptibility of powdered [Cu-2(2-amino-3-methylpyridine)(4)(OCH3)(2)](NO3)(2) has been examined in the range of 5 to 270 K. The dimer exhibits an antiferromagnetic exchange interaction The best fit to the Bleaney-Bowers equation was obtained yielding 2J = 133 cm(-1) with g = 2.02 and p = 2.58 x 10(2) for the complex in c.g.s. units. The dinuclear complexes are ESR silent in solid state and only a weak signal of monomeric impurities is observed Frozen solution ESR spectra suggests that the complexes dissociate when dissolved in DMF or DMSO.read more

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ZEHRA TALEBI ,NASRIN SADEGHY MOGHDAM ,SAEID AMANI ,

Primary-secondary wavelength spectrophotometric determination of trace amounts of silver in wastewater with 2,4-dibromo-6-carboxy-benzenediazoaminoazobenzene

 In the presence of Triton X 100 at pH 13 the reaction between silver (Ag+) and chromogenic reagent, 2,4-dibromo-6-carboxy-benzenediazoaminoazo-benzene (DBCBAA) was developed to form a red complex. This reaction was highly selective in the presence of disodium ethylene diamine tetracetate (Na(2)EDTA). Because of the interference of excess of DBCBAA the mw method named Its primary-secondary wavelength spectrophotometry (PSWS) was applied instead of the ordinary spectrophotometry for the determination of trace amounts of silver in wastewater Results showed that such a method gave out the better precision and higher accuracy thm the ordinary method By analyzing several wastewater samples, the relative standard deviations were less than 3.69% and the recovery rate of Ag between 93.5 and 104%.read more

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LEI WANG ,MEI TAO ,HONG WEN GAO ,

Impact of surface functional groups on the adsorption of aliphatic organic acids from aqueous solutions on granular activated charcoal

dsorption of aliphatic organic acid, such ar Formic, Acetic, Propionic and n-Butyric acids fi om aqueous solutions on the su;face of granular activated charcoal was studied as a function of stirring time, concentration of adsorbate and evacuation temperature (105 degreesC, 300 degreesC and 800 degreesC). Adsorption equilibrium war found to be established within four hours time in all cares of aliphatic organic acids having concentrations i.e. 0.005M and 0.01 M at temperature of 25 degreesC, which may be due to the uniform distribution of dive rites on the surface of adsorbent.Evacuation temperatures (105 degreesC, 300 degreesC and 800 degreesC) showed a considerable positive effect on the extent of adsorption and it war found that the higher adsorption of the organic acid on the sample evacuated at 800 degreesC may be due to the decomposition of surface oxides and evolution of CO and CO2 at high evacuation temperature, which make the surface non-polar and thereby increased surface area which result in greater adsorption of non-polar or weakly polar organic acid, because of high affinity for organic compounds whereas carbon possess surface functional group having high affinity for water molecules, and thereby decreasing the effective diameter of the pore opening which result in lower adsorption of organic compounds at 105 degreesC. The amount of adsorption of organic acids constantly increases as the homologous series is ascending Linear form of Freundlich's and Langmuir equations were applied to the adsorption isotherms data and it was found that both the equations obeyed them well.read more

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SULTAN ALAM ,MOHAMMAD ISHAQ ,YOUSUF IQBAL ,