M. I. Bhanger

Characterization of banana peel by scanning electron microscopy and FT-IR spectroscopy and its use for cadmium removal

This study describes the use of banana peel, a commonly produced fruit waste, for the removal of Cd(II) from environmental and industrial wastewater. The banana peel was characterized by FT-IR and scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) analysis. The parameters pH, contact time, initial metal ion concentration and temperature were investigated and found to be rapid ( approximately 97% within 10 min). The Langmuir adsorption isotherm was used to describe partitioning behavior for the system at room temperature. The value of Q(L) was found to be (35.52 mg g(-1)) higher than the previously reported materials. The binding of metal ions was found to be pH-dependent with the optimal sorption occurring at pH 8. The retained species were eluted with 5 mL of 5 x 10(-3)M HNO(3) with the detection limit of 1.7 x 10(-3)mg L(-1). Kinetics of sorption followed the pseudo-first-order rate equation with the rate constant k, equal to 0.13+/-0.01 min(-1). Thermodynamic parameters such as Gibbs free energy at 303K (-7.41+/-0.13 kJ mol(-1)) and enthalpy (40.56+/-2.34 kJ mol(-1)) indicated the spontaneous and endothermic nature of the sorption process. The developed method was utilized for the removal of Cd(II) ions from environmental and industrial wastewater samples using flame atomic absorption spectrophotometer (FAAS).

Synthesis and application of a highly efficient tetraester calix[4]arene based resin for the removal of Pb2+ from aqueous environment

The present study describes the Pb(2+) sorption potential of newly synthesized tetraester calix[4]arene (TC4) based resin from aqueous media. The TC4 resin was synthesized through diazotization reaction of TC4 with Amberlite XAD-4 in the presence of sodium nitrite in acidic medium. The TC4 resin was characterized by using different analytical techniques such as FT-IR, elemental analysis and scanning electron microscopy (SEM). The Pb(2+) removal ability of the resin from the aqueous environment has been evaluated by both batch adsorption as well as column studies. The experiments have been conducted involving the determination of effect of pH, adsorbate concentration, adsorbent dosage, contact time and temperature. Moreover, on the basis of kinetic studies, the pseudo-first-order and pseudo-second-order adsorption kinetics were calculated. The thermodynamic parameters of lead adsorption were also calculated. Equation isotherms such as Langmuir (L), Freundlich (F), and Dubinin-Radushkevich (D-R) were successfully used to model the experimental data. From the D-R isotherm parameters, it was considered that the uptake of Pb(2+) by TC4 resin is ion exchange mechanism. From the results it has been found that the TC4 resin is a versatile adsorbent for the removal of Pb(2+) from the aqueous environment. The study also confers its impact on human health, reinstate of polluted sites and other fields of material science.

An excellent fluoride sorption behavior of modified amberlite resin

The article describes a convenient method for the modification of Amberlite XAD-4 resin by introducing thio-urea binding sites onto the aromatic rings. The modified (ATU) resin has been employed for the quantitative sorption of fluoride ions in batch as well as column experiments. The parameters (i.e. pH, contact time, etc.) were optimized and desorption of fluoride ions was fulfilled by using 0.01 M HCl solution. The equation isotherms such as Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin were also successfully applied to model the experimental data. The sorption capacity of the ATU resin was found as 3.286 mmol g(-1). From the D-R isotherm parameters, it has been calculated that the uptake of fluoride ion by ATU resin occurs through ion exchange sorption mechanism. The study will contribute toward the remediation of fluoride polluted areas as well as in the various fields of materials science.

Sorption of organophosphorous pesticides onto chickpea husk from aqueous solutions.

The sorption efficiency of chickpea husk of black gram variety (BGH), for the removal of organophosphorous pesticides (OPPs), i.e. triazophos (TAP) and methyl parathion (MP) from aqueous media has been investigated. Optimization of operating sorption parameters, i.e. particle size, sorbent dose, agitation time, pH, initial concentration of sorbates, and temperature has been studied. The sorption data fitted well to Freundlich, Langmuir and Dubinin-Radushkevich (D-R) sorption isotherms. The maximum sorption capacities of BGH for TAP and MP were calculated to be 3.5+/-0.45 and 10.6+/-0.83 mmol g(-1) by Freundlich, 0.0077+/-0.021 and 0.025+/-0.0094 mmol g(-1) by Langmuir and 0.48+/-0.037 and 0.15+/-0.077 mmol g(-1) by D-R isotherms respectively, employing 0.2g of sorbent, at pH 6, 90 min agitation time and at 303 K. Application of first order Lagergren and Morris-Weber equations to the kinetic data yielded correlation coefficients, close to unity and showed partial intra-particle diffusion. The negative values of thermodynamic parameters, i.e. DeltaH (kJ mol(-1)), DeltaS (J mol(-1) K(-1)) and DeltaG (kJ mol(-1)) indicate the exothermic and spontaneous nature of the sorption process. The sorbed pesticides were recovered by sonication with methanol, making the regeneration and reutilization of the sorbents promising. The investigated sorbent exhibited potential applications in water decontamination, treatments of industrial and agricultural waste waters and thus productively demonstrated viable use of agricultural waste material.

Capillary gas chromatographic determination of putrescine and cadaverine in serum of cancer patients using trifluoroacetylacetone as derivatizing reagent

Trifluoroacetylacetone (FAA) derivatives of 1,4-diaminobutane (putrescine) (Pu) and 1,5-diaminopentane (cadaverine) (CA) were prepared and characterized by elemental microanalysis, IR, and mass spectrometry. Diamine derivatives were eluted from capillary gas chromatographic (CGC) column BP1 (12 m x 0.22 mm I.D.) or BP5 (50 m x 0.22 mm) with layer thickness 0.25 microm, using nitrogen as a carrier gas and flame ionization detection (FID). A solvent extraction procedure was developed for the extraction of Pu and CA from aqueous solution with a linear calibration range 0-20 microg/0.2 ml of extract with a detection limit of 0.5-0.6 ng/injection. The method was applied for the determination of Pu and CA in the serum of five cancer patients before and after radiotherapy. The serum of two healthy persons was also analyzed for Pu and CA contents. Pu and CA concentrations were found within the range 1.16-3.96 microg/ml and 0.88-1.46 microg/ml in cancer patients as compared to 0.11-0.16 microg/ml and 0.06-0.075 microg/ml respectively in healthy persons with a coefficient of variation (CV) within 0.62-5.47%. Pu and CA concentrations decreased on radiotherapy in cancer patients, but were much higher than in healthy persons.

Chemical composition of essential oils from Alhagi maurorum

Alhagi maurorum Medik. (Alhagi camelorum, Alhagi pseudalhagi) belongs to the Fabaceae family and is the species of Alhagi used in folk medicine as a diaphoretic, expectorant, laxative, purgative, and diuretic 1–3 . Literature survey revealed that flavonoids, fatty acids, coumarins, sterols, vitamins, and alkaloids are the active constituents of Alhagi species [3]. A. maurorum shows antiulcer [4], pharmacological [1], antidiarrheal [5], anti-inflammatory [6], urease-inhibition [7], analgesic [8], antiproliferative [9], antioxidant [10], and antinociceptive activities [11]. Phytochemical studies on A. maurorum show carbohydrates, tannins, unsaturated sterols, triterpenes, flavonoids, and flavanone glycosides [2]. The essential oils are used as raw material in different fields, including cosmetics, phytotherapy, aromatherapy, nutrition, perfumes, and spices [12]. The present investigation of A. maurorum describes the chemical constituents of the essential oil from leaves and stems using GC-MS 13 . Leaves and stems of the Alhagi maurorum plant were collected from Jamshoro (Sindh) in January 2011 and identified by Prof. Dr. Muhammad Tahir Rajput Dean, Faculty of Natural Sciences, University of Sindh, Jamshoro. A voucher specimen (1540) of the plant was deposited in the herbarium of the Institute of Plant Sciences, University of Sindh Jamshoro, Pakistan. Air-dried leaves and stems of the plant (70 g of each part) were subjected separately to dry steam distillation [24] for 3 h. The oil was separated from the water using n-hexane (HPLC grade), dried over analytical reagent grade anhydrous Na2SO4 and then stored at 4 C in sealed vials before GC-MS analysis. An agilent 6890 N GC instrument coupled with an MS-5975 inert XL mass selective detector and an auto sampler 7683-B injector was used for GC-MS analysis of the essential oil of A. maurorum. An HP-5MS column with dimensions of 30 m 0.25 mm i.d. and film thickness 0.25 m was used for the analysis. The temperature of the oven was held at 80 C for 2 min, raised to 200 C at 5°C/min (1 min hold), and then to 280 C at 20 C/min (3 min hold). A 1.0L sample was injected using a split mode (split ratio, 1:10). Helium gas was used as a carrier gas at a flow rate of 1.5 mL/min. An electron ionization mode with ionization energy of 70 eV was used for MS detection. The injector and MS transfer line temperatures were set at 220 and 290 C, respectively. The chemical composition of the essential oils obtained from the fresh parts of Alhagi maurorum (leaves and stems) is presented in Table 1. Sixteen compounds in leaves and 21 compounds in stems were identified, constituting over 56.8 and 76.7% of oils composition from both parts of A. maurorum, respectively. The volatile fractions of A. maurorum consisted of a complex mixture of different substances, with ketones (leaf – 4.4%, stem – 5.2%), acid derivatives (leaf – 1.5%, stem – 1.8%), terpenoids (leaf – 26.8%, stem – 18.7%), and hydrocarbons (leaf – 19.3%, stem – 50.6%). Also, heterocyclics (5.2%) were present in leaves, and aldehydes (0.2%) in stems. In the leaf oil, drimenol (23.2%), 9-octylheptadecane (9.3%), 4-hexyl-2,5-dihydro-2,5-dioxo-3-furanacetic acid (5.2%), 2-nonadecanone (4.4%) and pentacosane (4.3%) were found as the major constituents. In the stem oil, neophytadiene (39.3%), trans-ionone (5.4%), 6,10,14-trimethyl-2-pentadecanone (5.2%), actinidiolide (4.9%), and nonacosane (4.3%) were the main components. Drimenol, octadecane, eicosane, docosane, tetracosane, and squalene were common volatile constituents of the essential oils. The chemical class distributions of the volatile constituents are summarized in Table 1.

Exploitation of Beach Sand as a Low Cost Sorbent for the Removal of Pb(II) Ions from Aqueous Solutions

Abstract Beach sand is used to remove traces of Pb(II) ions from aqueous solutions. Effect of shaking speed, amount of sorbent, shaking time, nature and concentration of different electrolytes and deionized water along with buffer of pH 2–10 have been studied. Maximum sorption of Pb(II) ions (>94%) is achieved from 10−4M HNO3. Sorption data have been tested using Langmuir, Freundlich, and Dubinin‐Radushkevich (D‐R) sorption isotherms. Thermodynamic parameters such as ΔH, ΔS, and ΔG have been evaluated. Kinetics of sorption is followed by Morris‐ Weber, Reichenberg and Lagergren equations. Influence of diverse ions on the sorption of Pb(II) ions is also investigated.

Kinetic Study of an Effective Pb(II) Transport through a Bulk Liquid Membrane Containing Calix[6]arene Hexaester Derivative as a Carrier

The article describes transport of Pb(II) through bulk liquid membrane (BLM) containing calix[6]arene hexaester derivative (1) as a carrier. The effect of various parameters such as temperature, carrier concentration, stirring speed and type of solvent on the Pb(II) transport efficiency of the carrier through BLM was evaluated. The activation energy values for the extraction and re-extraction were found as 56.33 kJ mol−1 and 14.79 kJ mol−1, respectively. These values demonstrate that the process is diffusionally controlled by Pb(II). Observations indicate that the membrane entrance and exit rate constants (k1, k2) increase with increasing stirring speed as well as carrier concentration and decrease with increasing temperature. The effect of solvent on k1 and k2 was found to be in the order of CH2Cl2 > CHCl3 > CCl4.

Utilization of organic by-products for the removal of organophosphorous pesticide from aqueous media

Sorption potential of rice (Oryza sativa) bran and rice husk for the removal of triazophos (TAP), an organophosphate pesticide, has been studied. The specific surface area were found to be 19+/-0.7 m(2)g(-1) and 11+/-0.8m(2)g(-1) for rice bran and rice husk, respectively. Rice bran exhibited higher removal efficiency (98+/-1.3%) than rice husk (94+/-1.2%) by employing triazophos solution concentration of 3 x 10(-5) M onto 0.2 g of each sorbent for 120 min agitation time at pH 6 and 303 K. The concentration range (3.2-32) x 10(-5) M was screened and sorption capacities of rice bran and rice husk for triazophos were computed by different sorption isotherms. The energy of sorption for rice bran and rice husk was assessed as 14+/-0.1 and 11+/-0.2 kJ mol(-1) and kinetics of the sorption is estimated to be 0.016+/-0.002 and 0.013+/-0.002 min(-1), respectively. Intraparticle diffusion rate was computed to be 4+/-0.8 and 4+/-0.9 nmol g(-1)min(-1/2). Thermodynamic constants DeltaH, DeltaS and DeltaG at varying temperatures (283-323 K) were also calculated.

Nickel(II) chelates of some tetradentate Schiff bases as stationary phases for gas chromatography

Abstract Nickel(II) chelates of four tetradentate Schiff bases, bis(acetylacetone)ethylenediimine (H 2 AA 2 en), bis-(acetylacetone)propylenediimine (H 2 AA 2 pn), bis(acetylacetone)- dl -stilbenediimine ( dl -H 2 AA 2 S) and bis(acetylacetone)- meso -stilbenediimine ( meso -H 2 AA 2 S), were examined as stationary phases for gas chromatography. The complexes were coated with 3% OV-101 in the range 3–5%. The phases were packed in stainless-steel columns (3 m × 3 mm I.D.) and were examined for the separation of saturated aromatic hydrocarbons, heteroaromatic aldehydes, ketones, amines and alcohols. Kovats retention indices of alsohols, aldehydes and ketones increased with improvement in the separation when using mixed stationary phases, particularly 3% OV-101-5% dl -AA 2 SNi compared with 3% OV-101.