Tariq Mahmood Ansari

Organic acids pretreatment effect on Rosa bourbonia phyto-biomass for removal of Pb(II) and Cu(II) from aqueous media

The sorption of Pb(II) and Cu(II) form aqueous media by Rosa bourbonia waste phyto-biomass (RBWPB) pretreated with organic acids was investigated as a function of biosorbent dosage, initial metal ions concentration and contact time. The equilibrium biosorption data was analyzed using two kinetic models (pseudo-first order and pseudo-second order) and two isotherm models (Langmuir and Freundlich). The RBWPB was successfully applied for sequestration of both heavy metal ions; however, organic acids pretreatments decreased the metal adsorption capacity of RBWPB. The Langmuir model fitted well to the data, and the pseudo-second order kinetic equation could best describe the biosorption kinetics of Pb(II) and Cu(II) metal ions. Gibbs free energy indicated the spontaneous adsorption of Pb(II) and Cu(II) onto RBWPB.

Fourier Transform Infrared Spectroscopic characterization and optimization of Pb(II) biosorption by fish (Labeo rohita) scales

The present study reports the use of locally available fish (Labeo rohita) scales for Pb(II) removal from aqueous solutions under different experimental conditions. Maximum Pb(II) adsorption (196.8 mg g(-1)) occurred at pH 3.5. Pb(II) sorption was found to be pH, dose, initial metal concentration, contact time and shaking speed dependent while particle size and temperature independent. Experimental data of Pb(II) biosorption onto fish scales fitted well to Freundlich isotherm model in comparison to the model of Langmuir. The fast adsorption process in first 30 min followed by subsequent slow adsorption rate was suitably described by pseudo-second order model. In addition, this study was designed to evaluate the effect of physical and chemical pretreatments on surface properties of fish scales by the application of Fourier Transform Infrared (FTIR) Spectroscopic analysis. Physical pretreatments resulted in partial degradation of some functional groups. Alkaline pretreatments of fish scales did not have any significant influence on the nature of functional groups responsible for Pb(II) uptake, while acidic pretreatments resulted in degeneration of the most of functional groups on biosorbent cell wall. FTIR analysis confirmed the involvement of amino, carboxylic, phosphate and carbonyl groups in Pb(II) biosorption by fish scales.

Combined use of Alkane-Degrading and Plant Growth-Promoting Bacteria Enhanced Phytoremediation of Diesel Contaminated soil

Inoculation of plants with pollutant-degrading and plant growth-promoting microorganisms is a simple strategy to enhance phytoremediation activity. The objective of this study was to determine the effect of inoculation of different bacterial strains, possessing alkane-degradation and 1-amino-cyclopropane-1-carboxylic acid (ACC) deaminase activity, on plant growth and phytoremediation activity. Carpet grass (Axonopus affinis) was planted in soil spiked with diesel (1% w/w) for 90 days and inoculated with different bacterial strains, Pseudomonas sp. ITRH25, Pantoea sp. BTRH79 and Burkholderia sp. PsJN, individually and in combination. Generally, bacterial application increased total numbers of culturable hydrocarbon-degrading bacteria in the rhizosphere of carpet grass, plant biomass production, hydrocarbon degradation and reduced genotoxicity. Bacterial strains possessing different beneficial traits affect plant growth and phytoremediation activity in different ways. Maximum bacterial population, plant biomass production and hydrocarbon degradation were achieved when carpet grass was inoculated with a consortium of three strains. Enhanced plant biomass production and hydrocarbon degradation were associated with increased numbers of culturable hydrocarbon-degrading bacteria in the rhizosphere of carpet grass. The present study revealed that the combined use of different bacterial strains, exhibiting different beneficial traits, is a highly effective strategy to improve plant growth and phytoremediation activity.

Synergistic effect of interfacial phenomenon on enhancing catalytic performance of Pd loaded MnOx–CeO2–C hetero-nanostructure for hydrogenation and electrochemical reactions

Hetero-nanostructures have proven to be impressive materials due to their multi-functionalities in various catalytic applications. Here, the basic focus has been devoted to interface chemistry among different domains in the field of catalysis to develop an outstanding composite material with exceptional redox and catalytic properties in hydrogenation and as well in electrochemical reactions. The unique nano-hybrid material is synthesized by the loading of Pd nanoparticles onto MnOx–CeO2 mixed oxides. The heterogeneous catalytic ability for hydrogenation reactions were studied such as the reduction of organic pollutant 4-nitrophenol into 4-aminophenol and the hydrogenation of styrene into ethylbenzene. However, for electrochemical reactions, a comprehensive investigation as anode and cathode materials in direct formic acid fuel cells was performed. The strong reducing property of Pd enhanced the catalytic performance of mixed oxides and the synergistic effect of mixed oxides through interfacial phenomenon improved the performance of the hetero-nanostructured catalyst. The as-designed nanocomposite depicts high catalytic efficiency with low-cost economical standards.

Synthesis and application of alumina supported nano zero valent zinc as adsorbent for the removal of arsenic and nitrate

Arsenic and nitrate are ill-famed environmental pollutants that are responsible for various lethal diseases. Their removal from drinking water is very essential. In present study, newly synthesized alumina supported nano zerovalent zinc (Alumina-nZvZ) has been tested to remove arsenic and nitrate. Quantitative analyses of arsenic have been performed spectrophotometrically and while that of nitrates ions colorimetrically. After optimization of time and amount of adsorbent, Langmuir, Freundlich and D-R isotherms were applied to determine different parameters for the assessment of adsorption. Synthesized samples were characterized by scanning electron microscopy (SEM) to evaluate porosity and void size. Alumina coated with reduced ZnCl2 showed better efficiency for removal of arsenic and nitrate ions. Kinetics of adsorption was evaluated by using pseudo first-order and pseudo second-order rate equations.

Evaluation of automatic probe atomization for determination of elements in urine and whole blood by electrothermal atomic absorption spectrometry

A procedure is described for the determination of Cd, Co, Cr, Mn, Ni and Pb in Seronorm and Lanonorm reference materials and clinical samples. Accurate analyses of diluted specimens were achieved against aqueous standards. The use of high atomization temperatures (2400–2750 °C) minimized chemical interference from matrix components. High temperatues also improved the characteristic mass of Ga for probe electrothermal atomic absorption spectrometry, but caused a reduction in the sensitivity of Pb due to increased diffusional loss effects. The relative standard deviation values reported for Cd in human urine (1.1–7.6 µg dm–3) were mostly <10% and good precision was also obtained for Cd and Pb in whole blood and Cr, Mn and Ni in plasma protein solution. However, the precision achieved for Co, Ni and Pb in the reference urines (7–36%) might not be satisfactory for some applications. The results suggest that the probe method could be useful for the determination of elevated concentrations, caused by industrial exposure. Further work is required to assess the procedure for the determination of lower concentrations as, for most of the analytes, the concentrations were higher than normal levels.

Pharmacological investigations and Petra/Osiris/Molinspiration (POM) analyses of newly synthesized potentially bioactive organotin(IV) carboxylates.

A series of organotin(IV) carboxylate complexes: [Me2SnL2] (1), [n-Bu2SnL2] (2), [n-Oct2SnL2] (3), [Me3SnL] (4), [n-Bu3SnL] (5) and [Ph3SnL] (6), where L=3-(4-fluorophenyl)acrylic acid, have been successfully synthesized and characterized by FT-IR, NMR ((1)H, (13)C) and single crystal analysis. The ligand coordinates to tin atom via carboxylate group. Compound 4 was also analyzed by single crystal XRD analysis. Crystallographic data for trimethyltin(IV) complex showed that the tin has approximate trigonal bipyramidal geometry with the CH3 groups in the trigonal plane. The carboxylate groups bridge the adjacent tin atoms, resulting in polymeric chains. FT-IR and NMR data also support the 5-coordination geometry for the triorganotin(IV) derivatives. In the case of the diorganotin(IV) derivatives a six-coordinate geometry at the tin atom is proposed from spectroscopic data. The Me-Sn-Me bond angle in complexes 1 and 4 was determined from the (2)J[(119)Sn-(1)H] value as 138.4° and 111° that falls in the range of 5-coordinated trigonal bipyramidal and 6-coordinated octahedral geometries, respectively. The synthesized compounds were screened for their biological activities including antibacterial, antifungal and cytotoxicity. The compounds 4-6 exhibit excellent antibacterial, antifungal and cytotoxic activities. The cytotoxicity data reveals that the HL and 1-3 are almost non-toxic and exhibited LD50 values in the range 73.45-675.1μg/mL while 4-6 are found to be cytotoxic to mildly cytotoxic with LD50 values in the range 6.43-13.49μg/mL. The compound interacts with DNA via intercalation of aromatic ring into the base pairs of DNA resulting in hypochromism and minor red shift.

Development of Silver-Nanoparticle-Decorated Emulsion-Templated Hierarchically Porous Poly(1-vinylimidazole) Beads for Water Treatment

Water, the driver of nature, has always been polluted by the blind hurling of highly toxic contaminants, but human-friendly science has continuously been presenting better avenues to help solve these challenging issues. In this connection, the present study introduces novel nanocomposites composed of emulsion-templated hierarchically porous poly(1-vinylimidazole) beads loaded with the silver nanoparticles generated via an in situ approach. These nanocomposites have been thoroughly characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, Brunauer-Emmett-Teller, and field emission scanning electron microscopy. The appropriate surface chemistry, good thermal stability, swelling behavior, porosity, and nanodimensions contributed to achieve very good performance in water treatment. Owing to their easier handling and separation, these novel nanocomposites are highly efficient to remove arsenic and eriochrome black T with decent adsorption capacities in addition to the inactivation and killing of Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria.

Characterisation of mineralogical forms of barium and trace heavy metal impurities in commercial barytes by EPMA, XRD and ICP-MS.

This study was carried out to characterise the mineralogical forms of barium and the trace heavy metal impurities in commercial barytes of different origins using electron probe microanalysis (EPMA), X-ray diffraction (XRD) and inductively coupled plasma mass spectrometry (ICP-MS). Qualitative EPMA results show the presence of typically eight different minerals in commercial barytes including barite (BaSO4), barium feldspar, galena (PbS), pyrite (FeS2), sphalerite (ZnS), quartz (SiO2), and silicates, etc. Quantitative EPMA confirms that the barite crystals in the barytes contain some strontium and a little calcium, whereas trace heavy metals occur in the associated minerals. Analysis of aqua regia extracts of barytes samples by ICP-MS has shown the presence of a large number of elements in the associated minerals. Arsenic, copper and zinc concentrations correlate closely in all 10 samples. The findings suggest that barytes is not, as traditionally thought, an inert mineral, but is a potentially toxic substance due to its associated heavy metal impurities, which can be determined by an aqua regia digest without the need for complete dissolution of the barite itself. X-ray powder diffraction was not informative as the complex barite pattern masks the very weak lines from the small amounts of associated minerals.

Accumulation of some essential nutrients by lentil (Lens culinaris) plants at low potassium regimes

The effect of low K+ regimes on a salt‐tolerant line ILL 6796 and a salt‐sensitive line ILL 6439 of lentil (Lens culinaris) was studied in a pot experiment in glasshouse conditions. Plants of the two lines were treated with 78, 39, 19.5, and 9.75 mg K+ L‐1in the Rorisons nutrient solution. The salt‐tolerant line had a higher content of shoot dry matter at the lowest external K+ concentration than the salt‐sensitive line; the former was superior also in seed yield to the latter. K+ deficiency resulted in lowering the absorption of N and P in the leaves, roots, and seeds of both lines. However, the salt‐tolerant line ILL 6796 accumulated significantly greater amounts of N and P in the leaves than the salt‐sensitive line ILL 6439. K+ concentrations in the leaves and roots of both lines decreased with decrease in K+ concentrations of the growth medium, whereas Ca 2+ concentrations were little affected. ILL 6796 had a greater amount of Ca 2+ in the leaves than that in ILL 6439, but a reverse pattern was obser...