Browsing by Author "Balakrishna Prabhu, K."

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Adsorption of hexavalent chromium from aqueous medium using a new Schiff base Chitosan Derivative
    (Research India Publications subscription@ripublication.com, 2017) Balakrishna Prabhu, K.; Saidutta, M.B.; M Kini, M.
    Modification of chitosan biopolymer was achieved by grafting (3-phenyl-1H-pyrazole-4-carbaldehyde) by the Schiff base reaction to synthesize a new chitosan derivative (ChD). The formation of the product was confirmed by FTIR, XRD and 13CNMR analysis. The grafted molecule provided additional nitrogen bearing groups as binding sites. The new derivative was used to investigate the removal of Cr (VI) ions in water. The sorption was best favoured at a pH of 3.0. From the Langmuir isotherm, the maximum monolayer adsorption capacity for the adsorbent was determined (Qo=63.5 mg/g). The sorption data fitted satisfactorily to the Redlich-Peterson isotherm. The kinetics of adsorption was best described by pseudo-second order rate equation. The thermodynamic study revealed that the adsorption of Cr (VI) on to ChD was spontaneous and accompanied by increase in entropy. The metal removal was favoured at lower temperatures indicating that the adsorption was exothermic in nature. © Research India Publications.
  • No Thumbnail Available
    Item
    Improvement in performance of polysulfone membranes through the incorporation of chitosan-(3-phenyl-1h-pyrazole-4-carbaldehyde)
    (Cogent OA info@CogentOA.com, 2017) Balakrishna Prabhu, K.; Saidutta, M.B.; Isloor, A.M.; Hebbar, R.S.
    Pure polysulfone membranes are known to exhibit poor permeability, and high fouling. This study was conducted to explore the possibility of improving the permeation characteristics of polysulfone membranes by using a chitosan derivative as an additive. Polysulfone membranes blended with chitosan derivative 3-phenyl-1H-pyrazole-4-carbaldehyde (ChD) were prepared by the method of wet coagulation. The hydroxyl, amine and the imine functional groups present in the ChD evidently increased the hydrophilicity of the surface of the blended membranes which was confirmed by contact angle measurements. The contact angle of the blended membrane having 2 wt.% ChD was 62 ± 1 as compared to 70 ± 1 of neat polysulfone membrane. The SEM analysis of the blended membranes revealed a highly porous structure with a very thin surface skin layer, finger like projections in the sub-layer with a macro void structure at the base. The blended membranes also showed significant improvement in pure water flux of 351 L m?2 h?1 at 0.8 MPa trans membrane pressure (TMP) as compared to 24 L m?2 h?1 of neat polysulfone membrane at the same TMP. The anti-fouling test using bovine serum albumin exhibited improved anti-fouling characteristic of blended membranes with a maximum flux recovery ratio (FRR) of 57%. The heavy metal rejection study revealed that membrane P-1 showed maximum 36 and 29% rejection for Pb and Cu respectively. © 2017 The Author(s). This open access article is distributed under a Creative Commons Attribution (CC-BY) 4.0 license.