VOLUME 28, NO4, AUG 2006

Kinetics of Removal of Dyes from Aqueous Solution by Wood Charcoal of Bombax cieba Activated at 1000oC

The kinetics of sorption of basic dyes, (methyl blue and basic blue 3) from aqueous solution by charcoal activated at 1000oC, prepared from the wood of Bombax cieba was investigated. It was found that the adsorption process follow first order kinetics. The rate constant (k) increased with the rise in temperature showing endothermic nature of the adsorption process. Activation energies for methylene blue basic blua 3, were found to be 2.33 and 8.74 kj/mol respectively.read more

---

F K BANGASH ,A MANAF ,

The Determination of Zeolitic Water and Thermal Stability of Nickel Exchanged X-Zeolites by TGA and DTA

Five Sample of Ni2+ exchange X-zeolites were prepared by ion exchange technique and were studied by chemical analysis, thermogravimetric analysis (TGA) and differential thermal analysis (DTA) to determine their unit cell composition, Zeolite water and thermal stability. The percentage of cation exchange decreased with increasing the concentration of Ni2+ cations in the exchange solution. The water contents of the zeolite X increased with increasing the Ni2+ contents per u.c of the zeolite. The dehydration Na X completed at 380oC and those of Ni X-zeolite samples at 420-470oC and the total weight loss occurred at 800oC for Na X and Ni X zeolites at 900-980oC depending on the Ni2+ cation loading of the zeolite. The thermograms were of lumpy nature indicated formation of a series of intermediate structure during dehydration. The endothermic peak of dehydration shifted towards high temperature for Ni X-zeolites indicated H2O molecules are more strongly bonded to Ni2+ cations than Na+ cation. The positions of exothermic peaks indicated that Calcined NI X-zeolites samples are thermally less stable than Na X-zeolite. The DTA curves indicated that Na X-zeolite becomes amorphous at above 930oC and NI X-zeolites at 800-870oC. the above results are discussed and possible interpretations are given.read more

---

T H SHAH ,S AKBAR ,K DAD ,R SHAHNAZ ,

Characterization of Amorphous AIPO4 Surface Sites

ALPO4 surface processes weakly acidic AlOH and POH groups generated due to water chemisorptions on the surface. The presence of these group on were identified from the well-defined peaks in the infra red region at 510, 1000-1200, for PO bending/stretching respectively and 1650, 3400 and 3780 cm-1 for AlOH and POH, heat treatment at 300°C affects only the Bronsted acidic sites i.e., weakly acidic AlOH and POH at 1650,3400 cm1 and disappearance of the bend at 1400 cm whereas the lattice nature remains unaffected. Water adsorption again enhanced the bands at 1650 and 3400 cm-1 along with re-appearance of the band lost at 1400 cm-1.read more

---

M JAVID ,

Determination of Molybdenum (VI) as Complex with Bromopyrogallol red in Micellar Media of Tween 80

Molybdenum (VI) was determined spectrophotometrically with bromopyrogallol red as complexing reagent in aqueous. Phase in presence of a non-ionic surfactant.Tween 80 Beer’s law is obeyed, over the concentration range 0.6-1.mgmnL-1 with the detection limit 0.12 ngmL-1. The lmax molar adsorption, molar adsorptivity and sandell’s sensitivity were 480 nm. emax = (x 104 mol-1 cm-1) 0.6 and (15.9) ngcm-2. Validation of this has been made by comparing the results with those obtained by flame AAS, no significant difference was noted between the two methods at 95% confidence interval. The method is simple, accurate and economical and has been applied for the determination of molybdenum (VI) in industrial waste water samples.  read more

---

G A SHAR ,G A SOOMRO ,

Derivative Spectrophotometric Determination of Nickel (III) with 1-BItroso-2-napthanol in Aqueous Phase

A spectrophotometric and first derivative spectrophotometric determination of Ni(II) is carried out with  1-nitro-2-napthol as complexing reagent in aqueous phase using non-ionic surfactant Tween 40. The nickel is determined in the range 1.7-120 ngmL-1 with detection limit (2s) of 1.7 ngmL-1. The molar adsorptivity and Sandell’s sensitivity are emax 1.0 x (104 mol-1 cm-1) and 5.8 ngcm-2 at 452 nm. The optimum pH of the complex is 8. the critical micelle concentration (cmc) of Tween 40 is 5%. Adsorption studies in the first derivatives mode is carried out to determine the adsorption maximum of the complex fro higher sensitivity and to overcome interference due to the presence of certain other metals ions. The presents method is compared with that of AAS and no-significant difference is noted between the two methods at 95% confidence level.  The methods has been applied for the determination of Ni (II) in industrial waste water and edible oil samples.read more

---

G A SHAR ,G A SOOMRO ,

Analytical Investigation of Soil Inorganic Nutrients of Cholistan Desert-Pakistan

Desert oil inorganic nutrients have their geological influence on wild medicinal herbs, plants and crop production. Soil samples collected from different areas of Cholistan desert were analysed for pH, moisture, and soluble salt organic contents, Na+, K+, Ca2+, Mg2+, Fe3+, Al3+, Cl-, CO32-, HCO3-, So42_ and PO43-. pH was observed from 7.30 to 8.85. Average level of nutrients were found higher in the order Al3+ (4323.66±205.93)> Fe3+(289.54±160.77)> SO42- (266.19±215.59)> Cl- (247.08±248.48)> HCO3- (78.45±161.44)> CO32- (60.14±414.26)> Ca2+ (53.16±50.01) Mg2+ (18.95±19.39)> PO43- (18.72±24.20)> Na+ (17.75±15.34) K+ (15.81±18.51). Data analysis for soluble salts and CO32- has showed random variation in result from positive correlation for certain pairs of nutrients.read more

---

A N MEMON ,M H S WATTOO ,J IQBAL ,F H WATTOO ,S A TIRMIZI ,

Formation and Crystallization Studies of Na2O-CaO-SiO2-P2O5 Glasses

Calcium Phosphate based glasses and glass ceramics are known for their bio-active nature. In Na2O-CaO-SiO2-P2O5 system composition containing 40$, 45%, 51% SiO2 and 6 wt% P2O5 were studied with regard to ease of glass formation and crystalline. In the system large quantities of Calcium Oxide can be incorporated without significant increase in melting temperature. Crystalline behavior has been studied by iso-thermal heat treatment were 800oC,850oC,900oC. Different crystalline phases developed during heat treatment were analyzed by X-0ray Diffraction method.read more

---

S B NIAZI ,W A SHAH ,F MAHMOOD ,R AZEEM ,M P I QAZI ,

Determination of Heavy Metals in Medicinal Plants

Accumulation of heavy metals like Pb, Cu, Zn, Cr, Fe and Ni were determined in the medicinal plant parts including roots, stems, leaves and seeds by atomic adsorption Spectrophotometry.these plant which include Datura alba Nees, Withania somnifera L, Alhagi pseudalhagi Desv and Achyranthes aspera L are used locally for various types of body disorder. In all of the four plants samples, high pb was observed in the roots of Datura alba followed by the leaves of Achyanthes aspera and Withania somnifera. The concentration of Cr,Fe,Zn was found high in all the samples. The objective of this study was to investigate the concentration levels of toxic metals in plants that are used in herbal medicines by the local community.read more

---

F KHAN ,L KHAN ,WALI ULLAH ,I HUSSAIN ,I KHAN ,

A Kinetic Study of the Cleavage of Tin-Carbon Bond in Triphenyltin(IV) [2-(2,6-dichlorophenyl)aminophenyl acetate] by Ethyl Iodide

The pseudo-first order kinetics for the substitution reaction of P{h3SnL [L=2-(2,6-dichlorophenyl)aminophenyl acetate] with ethyl iodide have been studied in Ch2Cl2 at 20oC using controlled temperature controlled UV-Visible Spectroscopy. The reaction shows a first order dependence on both reactants. The rates of the reaction have been calculated and approximate rate constants have been determined for the cleavage of tin-phenyl bond. The reaction is believed to proceed through the associative mechanism.     read more

---

S AHMAD ,M ALTAF ,S SHAHZADI ,S ALI ,

Total Concentration and Chemical Speciation of Heavy Metals in Sewage Sediments

Bottom sewage sediments from six locations of Lahore city were studied to evaluate total concentration of selected heavy metals and also their chemical speciation using sequential chemical extraction method. Analyses of the extracts were carried out by atomic adsorption spectroscopy. The total concentration OF metals were in the sequence Fe> Mn> Ni> Cu> Zn> Co. the metals were partitioned into five operationally defined fractions i.e. exchangeable, bound to carbonate, associated with Fe-Mn oxides, associated with organic fractions and residual. Speciation analysis showed that the most of the metals were in the residual fraction. The next considerable proportion is associated with Fe-Mn oxides, than with organic fraction and least with carbonate and exchangeable fraction.read more

---

M A KHASMIRI ,T SHAFIQUE ,M TARIQUE ,F BASHIR ,