9 research outputs found
Removal of Chromium(VI) Ions from Aqueous Solutions and Industrial Effluents Using Magnetic Fe<sub>3</sub>O<sub>4</sub> Nano-particles
No full text The adsorption characteristics of magnetic Fe3O4 nano-particles synthesized by chemical co-precipitation for the removal of chromium(VI) ions from aqueous solutions and tannery effluents have been studied. The composition, size, morphology and magnetic properties of the nano-particles were characterized by FT-IR, XRD, TEM and VSM methods, respectively. Experiments were conducted in batch mode to observe the influence of different parameters such as pH, feed concentration, adsorbent dosage and temperature on the performance of the adsorbent. It was found that when the pH of the system was decreased from 7 to 2, the extent to which Cr(VI) ions were removed increased from 54% to 77%. The adsorption process was found to follow second-order kinetics and the rate constant was evaluated at 30 °C. The Langmuir isotherm was found to provide a good fit to the experimental data. The adsorption capacity of magnetite nano-particles towards Cr(VI) ions at room temperature was 2.9508 mg/g, with the value increasing to 3.4454, 3.7592 and 4.0475 mg/g at 40 °C, 50 °C and 60 °C, respectively. On the basis of the adsorption free energy change of 16.577 kJ/mol obtained at 30 °C, the adsorption mechanism was confirmed as being chemical in nature. The thermodynamic parameters for the adsorption process were also calculated from the experimental data. At an S/L ratio of 0.2 and under optimized conditions of pH, temperature and agitation, the removal of Cr(VI) ions from aqueous solution amounted to 85%. Regression analysis was performed and a correlation between percentage removal and operating parameters obtained. </jats:p
Removal of Cr(VI) ions using Fe-loaded chitosan carbonized rice husk composite beads (Fe-CCRCB): Experiment and quantum chemical calculations
No full textAdsorption and desorption of L-phenylalanine on nano-sized magnetic particles
No full textJournal of Engineering and Applied Sciences4839-4
Enhancement of biodiesel synthesis over highly active CaO derived from natural white bivalve clam shell
No full textAbstractWhite bivalve clam shell (WBCS), a good source of calcium carbonate collected from sea shore was subjected to calcination–hydration–dehydration treatment to obtain CaO with high activity. The performance of the newly obtained CaO from the calcination–hydration–dehydration treatment of WBCS and commercial CaO was tested for their catalytic activity via transesterification of waste frying oil (WFO). The results showed that the methyl ester conversion for the commercial CaO was 67.57% whereas it was 94.25% for the CaO obtained from calcination–hydration–dehydration treatment of WBCS at a 7wt.% catalyst (based on oil weight), methanol to oil ratio of 12:1, reaction temperature of 65°C and reaction time of 1h
Interaction of dpyatriz and Cu/Zn-dpyatriz complexes with human telomere DNA: The role of G-quadruplex formation and its effect on antitumor and antitelomerase activity
No full text217-2291,3,5-Triazine derivative of dipyridyl amine (dpyatriz) and the Cu(II), Zn(II) complexes have been prepared,
characterized by CHN, IR, NMR and mass measurements and interacted with HTelo8 and HTelo20, the two types of human
telomere repeat DNA (TTAGGG)n; n = 8, 20. The telomere DNAs have been treated with all three compounds (dpyatriz,
Cu-dpyatriz and Zn-dpyatriz) under parallel/antiparallel and random coiled conditions. The interactions are followed by
circular dichrosim measurements, fluorescent intercalator displacement (FID) assays and molecular docking studies through
MOE program. The free ligand and its Cu(II) and Zn(II) complexes stabilize predominantly antiparallel G-quadruplex form
under antiparallel and no salt conditions. The binding constant (Kb) values calculated for the ligand and complexes are in the
range of 1.9 x 105 M-1 to 4.2 x 107 M-1 under various conditions show the higher affinity of G-quadruplex conformations.
The FID assay using thiazole orange with HTelo20 clearly depicts the G-quadruplex stabilization through strong binding
mode. Also, all the three compounds dpyatriz, Cu-dpyatriz and Zn-dpyatriz show an intercalative mode of interaction with
antiparallel G quadruplex DNA in molecular docking studies. The compounds show cytotoxicity with the IC50 values in the
range of 50 – 90 nM, and antitelomerase activity in the range of 5 to 10 μM
Heavy metal removal from copper smelting effluent using electrochemical cylindrical flow reactor
No full textThe purpose of this study is mainly to evaluate the performance of the continuous recirculation flow cell at low current density and pH (the
pH at which the effluents are available) in removing heavy metals from copper smelting effluent by cathodic reduction. During the electrolysis at
different pH, % removal of heavy metals removal, energy consumption and heterogeneous reaction rate constants were investigated at given flow
rate and current density on the selected industrial effluent. The overall specific energy consumption at the pH 0.64 was observed to be lowest,
which is 10.99 kWh/kg of heavy metal removal
Biodiesel production from rubber seed oil using calcium oxide derived from eggshell as catalyst – optimization and modeling studies
No full textBiodiesel production from rubber seed oil using calcium oxide derived from eggshell as catalyst – optimization and modeling studies
No full textIn the present study, Calcium oxide (CaO) obtained from eggshells has been used as a heterogeneous catalyst for biodiesel production from highly viscous non-edible rubber seed oil (RSO). Characterization of synthesized catalyst was done with the help of scanning electron microscope equipped with Energy dispersive spectrometry (SEM-EDS), X-ray diffraction (XRD) and Fourier transform Infrared spectroscopy (FTIR). Response surface methodology (RSM) with central composite design (CCD) was used to optimize the process parameters and 1H-NMR (Nuclear Magnetic Resonance) spectroscopy analysis was performed to find the conversion of RSO to biodiesel. A conversion of 99.7% of RSO to biodiesel was obtained at 12:1 methanol to oil molar ratio, 4 (wt%) of catalyst, and 3 hour reaction time with a quadratic regression model of R2 of value 0.9566 was obtained. The composition of prepared biodiesel is estimated with the help of Gas Chromatogram-Mass Spectroscopy (GC-MS) analysis. Artificial Neural Network (ANN) with Levenberg-Marquardt algorithm was also trained to predict biodiesel conversion and the value of R2 obtained was 0.9976. It was observed that predicted conversion values from ANN were better when compared to prediction using RSM
Interaction of dpyatriz and Cu/Zn-dpyatriz complexes with human telomere DNA: The role of G-quadruplex formation and its effect on antitumor and antitelomerase activity
Get PDF1,3,5-Triazine derivative of dipyridyl amine (dpyatriz) and the Cu(II), Zn(II) complexes have been prepared, characterized by CHN, IR, NMR and mass measurements and interacted with HTelo8 and HTelo20, the two types of human telomere repeat DNA (TTAGGG)n; n = 8, 20. The telomere DNAs have been treated with all three compounds (dpyatriz, Cu-dpyatriz and Zn-dpyatriz) under parallel/antiparallel and random coiled conditions. The interactions are followed by circular dichrosim measurements, fluorescent intercalator displacement (FID) assays and molecular docking studies through MOE program. The free ligand and its Cu(II) and Zn(II) complexes stabilize predominantly antiparallel G-quadruplex form under antiparallel and no salt conditions. The binding constant (Kb) values calculated for the ligand and complexes are in the range of 1.9 x 105 M-1 to 4.2 x 107 M-1 under various conditions show the higher affinity of G-quadruplex conformations. The FID assay using thiazole orange with HTelo20 clearly depicts the G-quadruplex stabilization through strong binding mode. Also, all the three compounds dpyatriz, Cu-dpyatriz and Zn-dpyatriz show an intercalative mode of interaction with antiparallel G quadruplex DNA in molecular docking studies. The compounds show cytotoxicity with the IC50 values in the range of 50 – 90 nM, and antitelomerase activity in the range of 5 to 10 μM
