Mechanistic features of ultrasonic desorption of aromatic pollutants

Abstract This study attempts to identify the physical mechanism of ultrasonic desorption of aromatic pollutants. Specifically, an attempt is made to discriminate between the contributions made by the various physical effects of ultrasound and cavitation that generate high convection in the medium towards enhancement in desorption of pollutants. Two model adsorbents (activated charcoal and Amberlite XAD-4) and three aromatic pollutants (viz. phenol, p-cresol and nitrobenzene) have been chosen. The experimental techniques adopted in this study alter the characteristics of the cavitation phenomenon in the medium. The approach is to couple experimental results with simulations of cavitation bubble dynamics. Qualitative comparison between experimental and simulations results reveals that microturbulence generated by cavitation bubble plays insignificant role in enhancement of desorption. On the other hand, acoustic waves emitted by cavitation bubbles mostly contribute to enhancement of the desorption process. This is due to high pressure amplitude and discrete nature of the waves that create intense yet intermittent and chaotic convection in the medium. The experimental/modeling framework presented in this thesis could be extended to any other set of pollutant-adsorbent.

[1]  Vijayanand S. Moholkar,et al.  Mechanistic Studies in Ultrasound-Assisted Adsorption for Removal of Aromatic Pollutants , 2009 .

[2]  Fusheng Li,et al.  Effect of ultrasound on desorption kinetics of phenol from polymeric resin. , 2006, Ultrasonics sonochemistry.

[3]  V. S. Moholkar,et al.  Physical facets of ultrasonic cavitational synthesis of zinc ferrite particles. , 2010, Ultrasonics sonochemistry.

[4]  B. Hameed,et al.  Removal of phenol from aqueous solutions by adsorption onto activated carbon prepared from biomass material. , 2008, Journal of hazardous materials.

[5]  H. Schmidt-Traub,et al.  Effect of Ultrasound on Adsorption and Desorption Processes , 2003 .

[6]  Surendra Kumar,et al.  Adsorption of phenol and 4-nitrophenol on granular activated carbon in basal salt medium: equilibrium and kinetics. , 2007, Journal of hazardous materials.

[7]  Hongxia Xi,et al.  Effects of ultrasound on adsorption equilibrium of phenol on polymeric adsorption resin , 2002 .

[8]  E. Naffrechoux,et al.  Effects of ultrasound on adsorption-desorption of p-chlorophenol on granular activated carbon. , 2003, Ultrasonics sonochemistry.

[9]  E. Naffrechoux,et al.  An investigation of the mechanisms of ultrasonically enhanced desorption , 2007 .

[10]  K. Cheng,et al.  Effect of ultrasound and mechanical agitation on adsorption of 4-(2-pyridylazo) resorcinol (PAR) by amberlite XAD-2 , 1982 .

[11]  S. Allen,et al.  Comparison of optimised isotherm models for basic dye adsorption by kudzu. , 2003, Bioresource technology.

[12]  T. Leighton.  The Acoustic Bubble , 1994 .

[13]  H. Schmidt-Traub,et al.  Desorption of a fixed-bed adsorber by ultrasound. , 2002, Ultrasonics.

[14]  V. S. Moholkar,et al.  Physical features of ultrasound-enhanced heterogeneous permanganate oxidation. , 2010, Ultrasonics sonochemistry.

[15]  Zuoming Zhou,et al.  Ultrasound enhanced adsorption and desorption of chromium (VI) on activated carbon and polymeric resin , 2011 .

[16]  Aimin Li,et al.  Adsorption of phenolic compounds from aqueous solutions by a water-compatible hypercrosslinked polymeric adsorbent. , 2002, Chemosphere.

[17]  S. Chandrasekaran,et al.  Modelling of a batch sonochemical reactor , 1994 .

[18]  E. Naffrechoux,et al.  Desorption of Metal Ions from Activated Carbon in the Presence of Ultrasound , 2005 .

[19]  A. Torrents,et al.  Low-temperature thermal desorption of aromatic compounds from activated carbon , 1997 .

[20]  Detlef Lohse,et al.  Phase diagrams for sonoluminescing bubbles , 1996 .

[21]  Su Lin,et al.  Liquid-phase adsorption and desorption of phenol onto activated carbons with ultrasound. , 2006, Ultrasonics sonochemistry.

[22]  E. Naffrechoux,et al.  Ultrasonic desorption of p-chlorophenol from granular activated carbon , 2005 .

[23]  A. Szeri,et al.  Water vapour, sonoluminescence and sonochemistry , 2000, Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[24]  Vijayanand S. Moholkar,et al.  Physical insights into the sonochemical degradation of recalcitrant organic pollutants with cavitation bubble dynamics. , 2009, Ultrasonics sonochemistry.

[25]  B. Özkaya.  Adsorption and desorption of phenol on activated carbon and a comparison of isotherm models. , 2006 .

[26]  H. Tamon,et al.  Desorption Characteristics of Aromatic Compounds in Aqueous Solution on Solid Adsorbents , 1996 .

[27]  R. T. Yang,et al.  Desorption by ultrasound: Phenol on activated carbon and polymeric resin , 1998 .

[28]  Qingrui Zhang,et al.  Improved adsorption of 4-nitrophenol onto a novel hHyper-cross-linked polymer. , 2007, Environmental science & technology.

[29]  E. Naffrechoux,et al.  Modeling of adsorption isotherms of phenol and chlorophenols onto granular activated carbon. Part I. Two-parameter models and equations allowing determination of thermodynamic parameters. , 2007, Journal of hazardous materials.

[30]  V I Ilyichev,et al.  Spectral characteristics of acoustic cavitation. , 1989, Ultrasonics.

[31]  Vijayanand S. Moholkar,et al.  Mechanistic Approach to Enhancement of the Yield of a Sonochemical Reaction , 2007 .

[32]  L. Lv,et al.  Adsorption and desorption hysteresis of 4-nitrophenol on a hyper-cross-linked polymer resin NDA-701. , 2009, Journal of hazardous materials.

[33]  Vijayanand S. Moholkar,et al.  Mechanistic approach to intensification of sonochemical degradation of phenol , 2009 .

[34]  Zhang W Ming,et al.  Synergistic adsorption of phenol from aqueous solution onto polymeric adsorbents. , 2006, Journal of hazardous materials.

[35]  Y. Adewuyi,et al.  Sonochemistry: Environmental Science and Engineering Applications , 2001 .

[36]  J. Levec,et al.  Desorption of Phenol from Activated Carbon by Hot Water Regeneration. Desorption Isotherms , 1996 .

[37]  Aniruddha B. Pandit,et al.  Cavitation Reaction Engineering , 1999 .

[38]  R. T. Yang,et al.  Ultrasound Enhanced Adsorption and Desorption of Phenol on Activated Carbon and Polymeric Resin , 2001 .

[39]  Ji-qin Zhu,et al.  Removal of trace organic compounds from wastewater by ultrasonic enhancement on adsorption , 2005 .

[40]  T. Mason,et al.  Applied Sonochemistry: The Uses of Power Ultrasound in Chemistry and Processing , 2002 .

[41]  William H. Press,et al.  Numerical recipes , 1990 .

[42]  B. Gao,et al.  Two-step kinetic study on the adsorption and desorption of reactive dyes at cationic polymer/bentonite. , 2009, Journal of hazardous materials.