Time filter

Source Type

Hanumantharao Y.,Andhra Loyola College Autonomous | Kishore M.,H+ Technology | Ravindhranath K.,Bapatla Engineering College
Electronic Journal of Environmental, Agricultural and Food Chemistry | Year: 2012

Batch adsorption dynamics and equilibrium studies for the removal of Fluoride ions from aqueous solution using indigenously prepared Acacia farnesiana carbon (AFC), has been carried out under various experimental conditions at room temperature (30±1°C). Results found that percentage removal of Fluoride (F-) ions is increased with the decrease in initial concentration and is increased with increase in contact time initially and after 40-45 minutes, the % removal is found to be almost constant. Adsorption is highly pH sensitive and optimum pH range for appreciable or maximum adsorption of F- ion is found to be 6.5-7, with maximum absorption around 6.9. Adsorption data are modeled with isotherms and the different kinetic equations. Kinetics of adsorption is observed to be second order with intraparticle diffusion as one of the rate determining steps. The interactions of the adsorbent with Fluoride samples are characterized by making surface studies using X-ray Photo Electron Spectroscopy (XPS), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscope (SEM) and Energy Dispersive Spectrum (EDS) techniques. XPS and SEM-EDS data show evidence for Fluoride sorption on the AFC surface via inner-sphere complexation accompanying increased hydrogen bonding and surface oxidation. Removal of F- ions by indigenously prepared activated carbon, AFC, is found to be effective and hence AFC could be employed as an alternative adsorbent to the Commercial Activated Carbon (CAC) for water treatment for the removal of Fluoride ions.

Rao B.V.,Andhra Loyola College Autonomous
Journal of Thermal Analysis and Calorimetry | Year: 2010

Co(II), Ni(II), Cu(II) and Cd(II) chelates with 1- aminoethylidenediphosphonic acid (AEDP, H4L1), α-amino benzylidene diphosphonic acid (ABDP, H4L2), 1-amino-2-carboxyethane-1,1-diphosphonic acid (ACEDP, H5L 3), 1,3-diaminopropane-1,1,3,3-tetraphosphonicacid (DAPTP, H 8L4), ethylenediamine-N,N′-bis(dimethylmethylene phosphonic)acid (EDBDMPO, H4L5), O-phenylenediamine-N, N′-bis(dimethyl methylene phosphonic)acid (PDBDMPO, H4L 6), diethylene triamine-N,N,N',N;,NN-penta(methylene phosphonic)acid (DETAPMPO, H10L7) and diethylene triamine-N,N-bis(dimethyl methylene phosphonic)acid (DETBDMPO, H4L8) have been synthesised and were characterised by elemental and thermal analyses as well as by IR, UV-VIS, EPR and magnetic measurements. The first stage in the thermal decomposition process of these complexes shows the presence of water of hydration, the second denotes the removal of the coordinated water molecules. After the loss of water molecules, the organic part starts decomposing. The final decomposition product has been found to be the respective MO•P 2O5. The data of the investigated complexes suggest octahedral geometry with respect to Co(II) and Ni(II) and tetragonally distorted octahedral geometry with respect to Cu(II). Antiferromagnetism has been inferred from magnetic moment data. Infrared spectral studies have been carried out to determine coordination sites. © 2009 Akadémiai Kiadó, Budapest, Hungary.

Hanumantharao Y.,Andhra Loyola College Autonomous | Ravindhranath K.,Bapatla Engineering College
International Journal of ChemTech Research | Year: 2012

The surface sorption characteristics of activated carbon prepared from the shells of "Lagenaria siceraria" (calabash or bottle gourd or opo squash or long melon) towards fluoride has been investigated by varying the operational parameters such as initial concentrations, (1.5-15 mg/L), agitation time (10-70 minutes) and pH (3-10). Batch processes are employed. The experimental isotherms data are analyzed using Langmuir and Freundlich isotherm models. The data is best fitted with the Langmuir isotherm model. The calculated dimensionless separation factor, RL indicates that the adsorption of F- ion onto adsorbent is favorable. First order, pseudo-first order, second order and pseudo-second order kinetic equations and intra particle diffusion and pore diffusion models are used to examine the experimental data. It is found that the pseudo-second order kinetic equation describes the data of F- ion adsorption on adsorbent carbon adequately. The BET surface area pore size distributions, and physicochemical parameters for the adsorbent are obtained by N2 adsorption at 77 K. Surface morphology is also examined using Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDX) and X-ray Photo Electron Spectroscopy (XPS) before and after adsorption of F- ion. The chemical composition, elemental analysis and functional groups on the surface of the active carbon prepared are studied using XRD, and FT-IR techniques.

Rao Y.H.,Andhra Loyola College Autonomous | Ravindhranath K.,Bapatla Engineering College
Asian Journal of Chemistry | Year: 2013

A thorough study is made to assess the thermal and metallic ion pollution caused by Vijayawada thermal power station in the surrounding water bodies. Surface and ground water samples at judicially chosen sample stations have been analyzed at specific intervals of time for a period of nine months. It is found that the surface and ground waters are being contaminated with respect to heavy metal ions. Stratification of impounded waters of Krishna river at the point of discharge of effluents, is observed due to elevated temperatures and it is resulting in the depletion of dissolved oxygen content and thereby causing stress on biota of the lake; valuable fish species are being disappeared from placid waters of Krishna river and causing the migration of fisher man for their lively hood. Further, it is observed that heavy metal ions like Cr, Mn, Fe, Ni, Cu and Zn are being leached from fly ash due to the anaerobic conditions prevailing in the bottom of stratified pond waters. The accumulation of these ions due to bio-amplifications signals the alarming situation ahead for the people in five costal districts in Andhra Pradesh as the same impounding waters are being supplied for their drinking and agricultural purposes. Copyright © 2013 Asian Journal of Chemistry.

Papodu K.,Government J College | Hanumantha Rao Y.,Andhra Loyola College Autonomous | Ravindhranath K.,Koneru Lakshmaiah College of Engineering
Der Pharma Chemica | Year: 2014

The surface sorption nature of bio-adsorbents derived from plant materials of Terminalia arjuna, Atlantia monophylla (L) Correa and Madhuca indica plants have been probed towards the removal of Zinc ions from simulated polluted waters by varying the physicochemical parameters such as pH, sorbent concentration and time of equilibration and the extractions conditions have been optimized for the maximum removal of Zinc ions from waste waters. The extractions have been found to be pH sensitive. The optimum sorbent dosage, time of equilibration and % of removal have been found to be in the order leaves > barks > Ashes for the three plants studied. The effect of the co-ions on the % of extraction of Zinc has been studied and found that the common anions and monovalent ions are marginally interfered while cations like Cu2+ and Ni2+ interfered to some extent but Al3+ interfered markedly. The developed methodologies have been successfully applied to the samples collected from real polluted lake waters and industrial effluents.

Discover hidden collaborations